Routine Laboratory Research Articles

8070 Atypical New Onset Diabetes Mellitus in a Young Male: Is this LADA vs Type 1 or Type 2?

Abstract Disclosure: S.K. Devineni: None. S. Shaik: None. J.L. Gilden: None. Background: Recent literature suggests that autoantibody seropositivity is common in new onset autoimmune Diabetes Mellitus (DM), especially in younger patients. Latent autoimmune diabetes of adults (LADA), a form of adult-onset autoimmune DM. is considered a mix of type 1 and type 2 DM, sharing similar immune cell characteristics to both subtypes. Unlike type 1, LADA patients do not require insulin for glycemic control for the first six months after diagnosis. Unlike type 2, LADA patients are positive for single islet autoantibody, glutamic acid decarboxylase (GAD), and anti-gliadin antibodies. Patients with LADA often present with symptoms (polyuria, polydipsia, nocturia, fatigue, and visual changes). We present a case of new onset Diabetes Mellitus in a young male, autoantibody seronegative, at the time of diagnosis. Case report: A 19-year-old Caucasian male was sent to the Emergency Department with a serum blood glucose (BG) level of 579 mg% after routine blood tests. He denied any clinical symptoms and serum levels showed no elevation in ketones, nor bicarbonate levels, ruling out ketoacidosis. His hemoglobin A1c at that time was 14.7%. He denied prior knowledge of personal or family history of DM. or other autoimmune disorders. However, it was discovered that routine labs done 1 ½ months earlier on a Health Screen revealed BG=295 mg% with urine positive for ketones (80 mg/dl) and glucose (>1000 mg/dL). Physical Exam: (HT=178 cm; WT=79 Kg) was unremarkable. Autoantibodies for GAD 65, islet-cell, Zinc transporter 8, and Islet Antigen 2 were all negative. He was hospitalized for 9 days. BG levels were difficult to control and required increasing doses of both long acting and short acting insulin. He was discharged with insulin therapy (30 units of glargine at nighttime and 12 units of premeal aspart). One week later, the patient ate several gummy bears as a nighttime snack and subsequently woke up in the middle of the night feeling shaky and having blurry vision. BG was greater than 300 mg%. In the emergency room, he. received intravenous fluids. No insulin was given as his BG normalized and he was discharged. Later, a continuous glucose monitor revealed multiple hypoglycemic episodes. The patient was living in a situation where he only had limited access to certain foods, and thus his insulin regimen was decreased (28 units glargine and 10 units aspart for meals) Conclusion: We present the case of new onset atypical DM in a young patient whose insulin sensitivity and risk factors seem to resemble a pattern of type 1 DM; despite seronegative autoantibodies We predict that he may eventually seroconvert to type 1 DM. It is also possible that he may have an unusual presentation of LADA or type 2 DM, although he had no hyperglycemic symptoms. Presentation: 6/3/2024

6423 The Storm in a Healthy 26-year-old Hispanic Female

Abstract Disclosure: P.M. Reyes-Torres: None. M. Hernandez-Hernandez: None. Uncontrolled hyperthyroidism can cause thyrotoxicosis and lead to end-organ dysfunction known as thyroid storm. The incidence is .20 and .76 per 100,000 persons per year, with an incidence of 4.8–5.6 per 100,000 hospitalized patients. Of those hospitalized with thyrotoxicosis in the U.S., thyroid storm is diagnosed in 16%. Most commonly affects females, middle-aged patients, and Caucasians. Can be precipitated by acute illnesses, surgery, or non-compliance with medications. Symptoms are characterized by fever, cardiac and gastrointestinal dysfunction, and altered mentation along with impaired thyroid function tests.A 26-year-old Hispanic female presented to our ER complaining of palpitations, general malaise, dysphagia, and fevers after attending a social event 3 days before. Physical examination revealed a fever of 101F, restless patient with pressured speech, and diffusely enlarged non-tender thyroid without discrete nodules. Labs were remarkable for WBC: 12 000, urinalysis, b-HCG, and CXR were all negative. Burch-Wartofsky Point Scale: 55 and biochemical tests (TSH: 0.005 ml/UL, free T4 >5 ng/dL, Total T3: 8.5 ng/mL, Total T4: 28.87 uG/DL, Thyroglobulin 34.81 ng/mL) for which diagnosis of thyroid storm was made. She was transferred to the ICU and treatment was initiated with fluids, Propranolol 60 mg PO q4hrs, PTU 250 mg PO q4hrs, and Hydrocortisone 300 mg IV as loading dose then 100mg IV q8hrs. TSI and TRAb were ordered. Thyroid US remarkable for bulky thyroid gland with heterogeneous, increased vascularity, no obvious cystic/solid lesions seen. Repeated tests showed a decreasing trend of free T4: 4.71 ng/dL and Total T3: 2.42ng/dL for which PTU was discontinued and Methimazole 15 mg PO BID was started. Five days after treatment started, the patient continued symptom-free and was discharged with Propranolol 60 mg PO q6hrs and Methimazole 15 mg PO BID. TSI and TRAb samples were obtained but results were pending before discharge. Follow-up was scheduled in 2 weeks with routine labs but the patient was lost to follow-up.This case highlights the importance of early recognition and treatment of thyroid storm in Hispanics, undiagnosed patients given the presenting nonspecific, life-threatening symptoms. We conclude that our patient's cause of thyrotoxicosis was an undiagnosed case of Graves Disease and the storm was most likely triggered by an upper viral respiratory tract infection. This case could potentially help physicians identify hyperthyroidism in an earlier phase, reducing incidence, mortality, and hospitalizations of thyroid storm since a variety of mimics make the diagnosis challenging. Furthermore, we could contribute to updated statistical knowledge regarding the risk of patients with thyrotoxicosis developing thyroid storm which despite advancements in technology, are currently lacking. Presentation: 6/1/2024

8586 A Case Of Vitamin D Toxicity: From Michigan To Hawaii, Vitamin D Is Very High

Abstract Disclosure: A. Abu Limon: None. S.A. Aldasouqi: None. K. Patel: None. F. Akanbi: None. S. Khan: None. P. Kachhadia: None. We report a patient case who is a 46-year-old male, managed for Type 2 diabetes and Vitamin D deficiency (Defined by 25-hydroxy vitamin D levels less than 20ng/ml) at Michigan State University Endocrinology specialty clinic.He started taking 5000 IU daily Vitamin D supplements and on subsequent follow up his levels corrected to 88 ng/ml. His supplements were held.On a routine repeat lab check, his 25-hydroxy vitamin D level is reported to be higher than 200 ng/ml. Which meets the biochemical diagnosis of Vitamin D toxicity. His Calcium level was 9.7 mg/dL (N 8.7-10.3 mg/dL) and PTH-intact level was 38.3 pg/mL (N 14.0-72.0 pg/mL).On questioning the patient, he assured us he is still not on any Vitamin D supplements and that he just got back from a two-weeks long trip from Hawaii and spent hours daily on the beach without using sunblock.He is sure he didn't get tanning, sunburns, or any burns during that period.He was feeling fine without any symptoms or complications.While in Michigan during the winter, with limited number of sunny days, His 25-hydroxy vitamin D levels trended down slowly over the following few months, while Vitamin D supplements kept on hold.The most common cause of Vitamin D toxicity is excessive supplemental Vitamin D use. Other reasons can be related to excessive tanning or burns, that our patient didn't have. Excessive sun exposure or dietary intake is not a known reason to raise Vitamin D levels to a toxic range.Our patient lives in Mid-Michigan, an area known for low number of sunny days (150-180 sunny/ partly sunny days per year ), Which is a reason for high prevalence of vitamin D deficiency in the population. This is Compared to mostly sunny days on the Hawaiian Islands.Coming Back home for the winter season did help his Vitamin D levels to continue trending down back to a safe, non-toxic range. Presentation: 6/2/2024

8254 The Risk Of Thrombotic Complications In Patients With Post-COVID Syndrome Is High Even With Normal Coagulogram Values

Abstract Disclosure: A. Alieva: None. The high risk of thrombotic complications in patients with diabetes, even more increased in the post-Covid period, requires practicing physicians to be especially vigilant and carefully monitor the state of the hemostatic system and the function of the vascular endothelium. Routine laboratory tests may be insufficient for dynamic monitoring and timely detection of abnormalities. In this article, the author proposes the determination of cell adhesion molecules as a predictor of thrombotic complications in patients with type 2 diabetes mellitus in the post-Covid period. In our current study, VCAM-1 levels were elevated in all patients with type 2 diabetes within 24 months of COVID-19 infection and were not associated with increased von Willebrand factor or D-dimer or other coagulation abnormalities. This means that routine determination of coagulogram, D-dimer and von Willebrand factor may miss the stage of prothrombotic changes in the microvasculature. It is possible that an increase in the level of cell adhesion molecules precedes the appearance of other abnormalities in the hemostasiogram. Therefore, for patients with type 2 diabetes after a coronavirus infection with normal coagulogram values, it seems promising to determine the level of VCAM-1 molecules to prevent the occurrence of thrombotic complications. In addition, monitoring this indicator may be useful in determining the effectiveness of preventive therapy. Presentation: 6/3/2024

7336 Decades In The Dark: The Long Road To Diagnosing And Treating Hypophosphatasia

Abstract Disclosure: V.A. Mendpara: None. G. Madrigal Loria: None. L.Z. Khan: None. Background: Hypophosphatasia (HPP) is a rare bone disorder that results from deficient activity of the tissue non-specific isoenzyme alkaline phosphatase (ALP).[1] This case highlights a patient whose diagnosis of this treatable genetic condition was significantly delayed for almost two decades, despite receiving care at a prominent academic institution. The patient's persistently low ALP levels in routine lab tests were overlooked by multiple clinicians, leading to a delay in her care and eventual treatment. Case presentation: A 61-year-old Caucasian woman presented at the endocrinology clinic with complaints of severe fatigue, generalized pain, multiple childhood fractures, and ongoing dental issues. The rheumatology clinic to which she was referred for polyarthralgia diagnosed her with Hypophosphatasia (HPP) after noting chronically low alkaline phosphatase (ALP) levels from her previous charts ranging from 15 to 24 U/L (normal range: 34 to 123 U/L) over two decades. Her serum calcium, parathyroid hormone (PTH), and 25-hydroxy vitamin D levels were within normal ranges. A DEXA scan revealed normal bone density, effectively ruling out osteoporosis. Further investigation showed elevated Vitamin B6 levels at 219.6 nmol/L (normal range: 20.0 to 125.0 nmol/L), raising suspicion for HPP. The patient's family history provided additional insight, with her mother having a history of short stature and fractures and her son experiencing premature tooth loss at the age of 2. A genetic evaluation identified a heterozygous pathogenic variant in the ALPL gene (c.881A>C, p.Asp294Ala), confirming the diagnosis of autosomal dominant HPP. Initiating treatment with Asfotase alfa, a medication targeting HPP, resulted in a marked improvement in the patient's symptoms. Discussion: This case shows the diagnostic complexities of HPP, stressing the significance of actively screening for this condition via ALP levels in routine laboratory testing or during osteoporosis evaluations. The diagnostic process is critical to distinguish HPP from primary osteoporosis, as treatment and potential risks differ significantly. Inadvertent use of bisphosphonates can worsen hypomineralization and lead to atypical femoral fractures in HPP patients. Asfotase alfa enzyme replacement therapy, available since 2015, offers a targeted approach by replacing the enzyme defect, thereby mitigating symptoms. Heightened awareness among healthcare providers of HPP in adults holds the potential to enhance diagnosis rates and facilitate improved treatment outcomes for this highly treatable condition.[1] Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, Eighth Edition. ASBMR. Presentation: 6/2/2024

8226 A Diagnostic Challenge: Factitious Hypobicarbonatemia in Severe Hypertriglyceridemia

Abstract Disclosure: U. Rafat: None. S. Azmat: None. M. Siddiqui: None. R. Alshantti: None. D. Kircheva: None. V. Trendafilova: None. Background: Serum CO2 levels measured by a chemistry analyzer usually correlate with calculated bicarbonate levels on an ABG. There are some instances however, when this is not the case. Severe hypertriglyceridemia can cause serum bicarbonate levels to appear falsely low on metabolic panel. Clinical Case: A 48-year-old man was referred to Endocrinology Clinic for evaluation of hypogonadism and severe hypertriglyceridemia. Routine labs revealed a plasma CO2 of 11 mmol/L (20-31). Na was 133 mmol/L (136-145), K was 4.4 mmol/L (3.5-4.7), Chloride was 101 mmol/L (98-109) and anion gap was 25 (8-20) measured using a Siemens Vista enzymatic chemistry analyzer. His triglycerides were > 1100 mg/dL (0-150), above upper detection limits of the analyzer. The patient reported fatigue and mild abdominal pain. He was admitted to the hospital for further evaluation. His lipase was 41 U/L (12-73), lactic acid 1.2 mmol/L (0.50-2.20). ABG showed pH of 7.41, HCO3 of 26.6 mmol/L (22-29), and anion gap of 7 (10-20). The patient was well-appearing with normal vital signs and normal physical exam. He was made NPO and started on pravastatin, fenofibrate and fish oil. Once his triglycerides were < 1000 mg/dL, he was started on a very low-fat, low-carbohydrate diet. The CO2 level on BMP normalized on day 3 of hospitalization, when triglycerides measured 1010 mg/dL. No other treatment was given for the low CO2 levels. It does not appear that other lab indices were significantly affected by the hypertriglyceridemia. Review of Literature: A BMP measures serum total carbon dioxide using a chemistry analyzer using either an enzymatic/spectro-photometric method, or an electrode-based method; an ABG sample calculates plasma bicarbonate with the Henderson-Hasselbach equation, using the pH and partial pressure of pCO2 in the sample. Enzymatic analyzers measure CO2 using spectrophotometry and decrease in light absorbance is proportional to the sample’s CO2 levels. It is postulated that severely high triglycerides can interfere with this reaction and cause spuriously low CO2 levels, a phenomenon called pseudohypobicarbonatemia. One proposed mechanism for interference with the enzymatic assay method is turbidity causing a falsely low measured CO2 level. Verghese et al found that the severity of the CO2 measurement error positively correlates with the severity of triglyceride elevation. Conclusion: Awareness of the phenomenon of hypertriglyceridemia-induced pseudohypobicarbonatemia can prevent misdiagnosis or delays in diagnosis, as well as unwarranted testing and treatment. Presentation: 6/3/2024

12268 Hypercalcemia Alert: Exploring The Link To Isolated Bone Marrow Sarcoidosis

Abstract Disclosure: M. Renzu: None. C.M. Hubers: None. V. mehta: None. A. Qazi: None. D.K. Yerasuri: None. Introduction: Sarcoidosis, a complex disorder marked by granuloma formation in diverse organs, often affects the lungs, but can involve various systems as well. Rare cases of bone marrow involvement may mimic conditions like multiple myeloma, emphasizing the need to consider sarcoidosis in patients with bone marrow abnormalities, especially those without typical myeloma features. Case Presentation: A 79-year-old white male with a medical history of hypertension, hyperlipidemia, deep venous thrombosis, prostate cancer in remission, chronic knee pain, and basal cell carcinoma presented for pre-operative evaluation, as he was scheduled for an elective orthopedic procedure. On routine lab work, he was found to have acute hypercalcemia and normocytic anemia. This finding raised suspicion for an underlying systemic pathology. He reported that he did not take any calcium or vitamin D supplements at home. Subsequent endocrine assessment, including evaluation of parathyroid hormone and vitamin D levels, revealed a non-PTH-mediated hypercalcemia. The persistence of hypercalcemia prompted further investigations, including assessments for multiple myeloma by oncology. The workup was negative for multiple myeloma but significant for granulomas on bone marrow biopsy, a finding consistent with sarcoidosis. Additionally, angiotensin converting enzyme levels were elevated at the time of diagnosis. Interventions led to the resolution of hypercalcemia following steroid therapy of prednisone 20 mg daily and close follow up with endocrinology. As part of his follow up, ACE levels are being regularly monitored, with the patient going for lab work every other month. Discussion: Bone marrow biopsies rarely reveal granulomas and sarcoidosis accounts for only a very small percentage of these findings. The standard workup for sarcoidosis typically does not include bone marrow biopsies. By integrating biopsies into the standard diagnostic protocol researchers may gain insights into the etiology and mechanisms driving this manifestation of sarcoidosis, ultimately improving diagnostic accuracy and patient care. Distinguishing sarcoidosis from multiple myeloma also poses diagnostic challenges, necessitating thorough evaluation in patients with bone marrow abnormalities. Despite its rarity, clinical suspicion for sarcoidosis should be considered in patients with underlying hematologic disorders or malignancies. Additionally, sarcoidosis exhibits geographical variation, being less common in Japanese men and more prevalent in African American women. This highlights the importance of considering demographic factors when evaluating patients for sarcoidosis and its extrapulmonary manifestations. Long-term outcomes in isolated bone marrow sarcoidosis remain unclear, warranting surveillance for progression to multiple myeloma or other lymphoproliferative disorders. Presentation: 6/2/2024

8557 Osteitis Fibrosa Cystica as the Initial Manifestation of Severe Primary Hyperparathyroidism: A Case Report

Abstract Disclosure: L.A. Robles Gomez: None. G. Gill: None. A. Vincent, DO: None. A. Mahmoud, MD: None. Introduction: Osteitis fibrosa cystica (OFC) is a pathognomonic yet uncommon finding of hyperparathyroidism seen in less than 2% of patients with primary hyperparathyroidism in Western countries. We present a case of infrequent finding of late-stage severe hyperthyroidism with asymptomatic hypercalcemia and incidental findings of osteolytic bone lesions. Clinical Case: A 28-year-old female with a history of PCOS, fatigue, and chronic abdominal pain presents to the clinic after recent work-up during an ED visit demonstrated incidental findings of osteolytic bone lesions in the setting of mild hypercalcemia. Physical examination was relatively unremarkable except for mild tenderness to palpation on the right lower quadrant. Laboratory significant calcium 10.7 mg/dl (8.6-10.2 mg/dL), albumin 3.6 g/dL, Creatinine 0.56 mg/dL, GFR 127 mL/min, Alkaline phosphatase 187 IU/L (37-127 IU/L), AST 24 IU/L, ALT 45 IU/L, Intact PTH and calcium: PTH 413 pg/mL (15-65 pg/mL), Calcium 11.5 (8.7-10.4 mg/dL), Bone Specific Alkaline Phosphatase: 54.5 mcg/L (4.7-17.8 mcg/L), Phosphorus 2.1 mg/dL (2.4-4.8 mg/dL), Magnesium 1.7 mg/dL (1.5-2.5 mg/dL), Vitamin D 25 10 mg/mL (20-100 ng/mL), TSH 2.12 uIU/mL (0.46-5.05 uIU/mL). CT abdomen pelvis w/o contrast with multiple predominantly lytic expansile bone lesions, mainly in the pelvis, with the most extensive 6.2 cm lesion in the superior, posterior right ilium, the anterior acetabulum, and the posterior right ischium. A prior CT done in 2018 showed a similar distribution of lytic lesions. The patient denied any previous personal or family history of hypercalcemia or parathyroid abnormalities despite a review of prior outside records revealed abnormal labs dating back to 2018 with intact PTH 406 pg/mL, calcium 10.3 mg/dL, Ionized calcium 10.7 mg/dl (3.30-6.0 mg/dL), albumin 3.3g/dL, alkaline phosphatase 288 IU/L. The patient denied prior symptomatology of hypercalcemia, including renal stones, or prior treatment for hypercalcemia. Further work-up was ordered, and the patient was referred to endocrine surgery for management. Conclusion: Osteitis fibrosa cystica (OFC) has become a rare manifestation of primary hyperparathyroidism (PHPT) due to early diagnosis of hypercalcemia by routine lab monitoring. Skeletal findings typically seen on PHPT can vary from bone reabsorption-acroosteolysis, subchondral bone resorption, brown tumors, salt-and-pepper skull, and osteopenia. Subchondral reabsorption around specific joints commonly affects pubic symphysis and sacroiliac joints, as seen in our patient. The mechanism is due to PTH-mediated osteoclastic absorption of bone and surrounding cartilage. Due to the rare presentation of PHPT with associated osteitis fibrosa cystica, diagnosis requires a high degree of clinical suspicion, as delayed diagnosis can lead to avoided manifestation, as described by our report. Presentation: 6/3/2024

A successful outcome in four puppies sustained swimmer puppy syndrome.

Swimmer puppy syndrome (SPS) is a rare condition that affects neonatal animals. The affected puppies are unable to stand, remain in sternal recumbency with their legs splayed laterally and ambulate with typical swimmer-like movements. This study reports the clinical findings and discusses the treatments and outcomes in four puppies of various breeds with clinical signs of SPS. Previous medical records of the animals were reviewed for history, clinical features, radiographic findings and choice of treatment. Treatment follow-up was evaluated at 15, 30, 45 days and 6 months. In three puppies all limbs were affected. In one case only the forelimbs were affected, while the hind limbs remained normal. Clinical, orthopaedic and neurological examinations, routine laboratory findings and tidal breathing flow-volume loop measurements were normal. Concurrent problems occurred in two animals and included slightly deformed chest and ventrodorsal flattening of the thorax with a slight right displacement of the heart. For the management of SPS, chest and hobble bandages were used, as well as physiotherapy and environmental management. Three puppies recovered completely after 45 days of treatment. In one case the therapy was discontinued after 2 weeks. In this case, the puppy could stand, but mild abduction of the forelimbs and lameness were obvious after 6 months. Intensive physiotherapy contributed to positive outcomes even in older puppies. Also, to the authors' knowledge, this is the first report of tidal breathing flow-volume loop measurement for dogs with pectus excavatum.

B-034 Performance Evaluation of the Total Bile Acids (TBA) Assay on Mindray BS-2800M Analyzer

Abstract Background Bile acids (BA) are synthesized in the liver and secreted into bile. The function of BA is to promote absorption of lipids including fat-soluble vitamins. During liver diseases such as viral hepatitis and liver injury by hepatotoxic drugs, and cholestasis condition, BA secretion to bile is impaired, causing serum BA level to rise. Therefore, the determination of serum BA can be used as a sensitive indicator of liver function. TBA reagent contains NADH that requires pH ≥ 9 to be stable that is usually difficult to be maintained during reagent opened and stored on the analyzer. Meanwhile, 3α-Hydroxysteroid Dehydrogenase (3α-HSD) is required for the reaction. 3α-HSD is sensitive to pH condition. Minor changes in pH results in significant changes of enzyme activity. We formulated our TBA reagent with prolonged stability when reagent is onboard on the analyzer. This study evaluated the performance of the new Mindray TBA assay on Mindray BS-2800M. Methods TBA assay was based on the method with coupled Thio-NAD and NADH reaction for BA. The R1 contains Thio-NAD. The R2 contains NADH and 3α-HSD. R1 is incubated with serum sample containing BA for 5 min at 37°C and R2 is then added. During further incubation in the presence of Thio-NAD, 3α-HSD converts BA to 3-ketosteroids and Thio-NADH. The reaction is reversible, and 3α-HSD can convert 3-keto steroids and Thio-NADH to BA and Thio-NAD. In the presence of excess NADH, enzyme cycling occurs efficiently and the rate of formation of Thio-NADH is determined by measuring specific change of absorbance at 412 nm. Two-point-line calibration is used by this assay. The TBA concentrations for the test samples are obtained by the absorbances of test samples from the calibration line. The performances of precision, linearity, onboard stability, interference (hemolysis, lipid and bilirubin), correlation are evaluated following CLSI protocols. Results The precision study was run according to EP05A3 with two commercial controls (about 21 and 36μmol/L) and two serum sample pools(about 9.9 and 24.2 μmol/L)on the Mindray BS-2800M system. The repeatability and within-lab CVs ranged from 0.74% to 1.97%, respectively. The linearity of the assay was determined as from 2.0 μmol/L to 180 μmol/L. The reagent onboard stability is for 28 days without recalibration that is superior to TBA reagents from other manufacturers. The interference of hemolysis, lipid and bilirubin are with less than ±10% impact with hemolysate Hemoglobin up to 500 mg/dL, Intralipids up to 500 mg/dL, and Conjugated bilirubin up to 30 mg/dL, Unconjugated bilirubin up to 30mg/dL. This assay (Y) also correlated well with SEKISUI TBA assay (x), (Y = 0.9965X + 0.2694, r= 0.9993). Conclusions From this evaluation, we concluded that Mindray TBA assay can measure serum TBA precisely and accurately with good performances, especially for onboard stability. It is suitable for use in routine clinical laboratories.

A-095 A New CO2 Assay with Concentrated Reagent Having Superior Onboard Stability on Mindray BS-2800M Analyzer

Abstract Background Measurement of total content of CO2 in serum or plasma can be used to assist in the diagnosis of various acid-base disorders. There are small amounts (about 0.04%) CO2 in the earth’s atmosphere, or more in an enclosed clinical laboratory space. The environmental CO2 could be dissolved into the CO2 reagent continuously, in particular at lowered temperature when it is opened and stored on the system, which leads an impact on CO2 assay performance. Presently, competitors mainly use additional inserts or with small opening of the reagent container to reduce the contact with air from reagent, to improve its onboard stability. Here, we designed a new CO2 assay by optimizing the reagent formulation with a new protection mechanism to reduce the amount of CO2 absorption to the reagent and improved its onboard stability. This study evaluated performances of the new CO2 assay on Mindray BS-2800M analyzer. Methods Mindray CO2 assay with concentrated reagent is based on PEPC (Phosphoenolpyruvate Carboxylase) enzymatic method. It is designed with an innovative mechanism of reagent formulations with a protective layer of chemical(s) on top of the reagent that prevents CO2 from entering the reagent and reduced its impact to its on-board stability. The onboard stability was conducted with a constant reagent consumption mode to simulate as it in clinical lab use. The onboard study used two levels of Quality Control materials and serum pools. According to CLSI protocols, the following assay performances were evaluated: onboard stability, precision, method comparison, linearity, and interference. Results On Mindray BS-2800M analyzer, Mindray CO2 assay demonstrated an excellent onboard stability. With uncapped reagent on the system, the stability is for 21 days without recalibration, with less than ± 5% deviation from day zero. In parallel onboard stability studies, with Roche CO2 reagent on Cobas c701 system, the relative deviation from day zero was found to be within ±10%; and other three manufacturers` results with deviation exceeded ±10% vs. day zero in 7 days. The linearity of Mindray CO2 assay was determined as from 2.0 to 50.0 mmol/L. Our CO2 assay correlated well with Roche CO2 on Cobas c701 (Mindray = 1.0032 * Roche - 0.0186, r≥0.99). The repeatability and with-lab CVs were ranged from 0.64% to 3.41%, respectively. There was no significant interference (<±10%), at CO2 concentration of 15 mmol/L with bilirubin up to 60 mg/dL,hemolysate up to 800 mg/dL, Intralipid up to 1000 mg/dL, triglycerides up to 1000 mg/dL. Conclusions On Mindray BS-2800M analyzer, the new CO2 assay demonstrated a good ability against environmental CO2 inference in 21 days of onboard time. The new CO2 assay also shown good performances in precision, correlation (accuracy) and anti-interference from endogenous substances. Therefore, we conclude that the new Mindray CO2 assay is suitable for routine clinical laboratory use.

B-102 The Impact of Protein / Protein Interactions on Serum Free Light Chain Assay Calibration

Abstract Background Since 2001, Serum Free Light Chain measurements have become established as routine clinical laboratory tests. Katzmann (2002) published a reference interval based on 282 normal samples establishing a ratio reference range 0.26-1.65. Whilst kappa and lambda measurements are of little diagnostic value, kappa/lambda ratio gives a strong indication of monoclonal gammopathy. In recent years, it has been suggested that the ratio may have changed. Here we present investigations identifying protein/protein interactions that may account for the discrepancies between QC release and real-world data; identifying a remediation step which will allow verification of the published ratio. Methods The manufacturers QC release data was reviewed for kappa, lambda and kappa/lambda ratio for all lots from 2018-2023, and compared to published data. To mimic field observation, an accelerated stability study was performed on standard calibrators and protein/protein interactions identified using western blot. Subsequently, calibrators were depleted of alpha-1 antitrypsin (A1AT) and other serum proteins using specific affinity chromatography; accelerated stability was repeated. A calibrator of pure polyclonal free light chains (FLC) in human serum albumin was produced in the presence/absence of A1AT and additional interfering serum proteins. Results At release, the average kappa reference range was 7.2-29.5 mg/L (62 kits, 9 different US blood donor sera collections and 3852 data points) and 7.7-24 mg/L for lambda (78 kits, 9 different US blood donor sera and 4664 data points), with a kappa/lambda ratio of 0.45-1.69. There was minimal change over 5yrs to these measurements. Analysis of FLC calibrators during an accelerated stability identified interactions between kappa FLC and ubiquitous serum proteins, including A1AT. The standard calibrator activity declined by 14.9±0.1% (mean±SEM) over a 4-month accelerated period @22oC, equivalent to 16 months real time. Calibrators depleted of A1AT and specific additional serum proteins showed significantly less decline in activity 1.4±1.4%, p<0.001. When blood donor sera were analysed using the standard calibrators following 4 months at 22oC, the results showed an increase in the reported kappa concentrations compared to those generated from frozen calibrators (19.0[15.4-22.5] to 21.3[17.0-26.0] mg/L, 12.5±3.8%, p<0.001). This observation was mirrored in kappa/lambda ratio (1.3[1.1-1.5] to 1.4[1.2-1.7] mg/L, 12.5±3.8%, p<0.001) and when clinical patient samples were assessed (30.1[14.0-47.1] to 34.3[15.5-56.9] mg/L, 13.8±1.4%, p<0.001). The depleted calibrator did not report an increase in sample results. FLC+HSA calibrators, when spiked with either physiological concentrations of A1AT or other serum proteins, showed a 16.7% and 15.3% decrease in activity respectively, compared to FLC+HSA calibrators without additional proteins. Conclusions At release, US blood donor sera have different absolute kappa mg/L compared to the published reference interval, but these changes do not invalidate the published kappa/lambda ratio, in contrast to recent reports and have not changed since 2018. An unpredictable kappa/protein interaction was observed, particularly with A1AT in a time dependent fashion, which correlated to a reduction in calibrator activity. Removal of A1AT and other specific serum proteins remediated the issue, and the kappa/lambda ratio was verified irrespective of the age of the calibrator.

A-297 Feasibility of a novel Seegene Multiplex PCR panel for the simultaneous detection of HSV-1, HSV-2, VZV and Mpox: a focus on inclusion, confirmation and LOD assessment

Abstract Background Characterized by atypical presentations of short prodromal symptoms, variations in clinical staging, non-uniform presentation of rash, and varied syndromes of proctitis and pharyngitis, the WHO declared the 2022 Mpox outbreak a global public health emergency in July 2022. The overlap of clinical presentation with other causes of vesicular lesions identified gaps in the diagnostic tests available for MPXV and highlighted the need for a multiplex PCR approach to the diagnosis of HSV, VZV, and MPXV among patients presenting with vesicular lesions. Currently, no FDA cleared multiplex approach offering a single unified approach to the diagnosis of HSV, VZV, and MPXV from a single sample exists. Multiplex assays offer a role in diagnostic support where clinicians are challenged to determine the causative agent because of overlap. Furthermore, no assay capable of providing MPXV clade II reporting, needed for compliance to select agent reporting rules, exist for routine clinical labs. This study outlines the initial feasibility of Seegene’s multiplex HSV, VZV, MPXV PCR assay, highlighting the LOD assessment from the 1st WHO International Standards, ZeptoMetrix® NATtrolTM Controls, and custom plasmids. Methods Gene targets representing conserved, differentiated regions of HSV-1, HSV-2, VZV, MPXV, and MPXV clade II were identified through phylogenetic analysis. A total of 28 oligonucleotide combinations, were applied to Seegene’s proprietary amplification and detection process creating a multiplex assay capable of 8 unique detection signals in 5 channels using the BioRad Opus® 96. 1st WHO International Standards (IS) for HSV-1/2, VZV, ZeptoMetrix® NATtrolTM and custom designed plasmids controls were titrated and spiked into Copan UTM supplemented with 5% HeLa cells and used to define target LOD panels ranging in concentrations tested with multiple replicates. Sample processing, DNA extraction, and PCR amplification were performed on the Seegene Starlet® automated liquid handler and BioRad® OPUS 96 using Seegene software. Results Detection rates for HSV-1 at target concentrations of 1x102 IU/ml (WHO) and 6.17x100 copies/ml (NATtrolTM) were 100%. Detection of HSV-1 with plasmid DNA at target concentrations of 1.25x101 was 95%. Detection rates for HSV-2 were 100% at 5x102 IU/ml (WHO) and 5.56x101 copies/ml (NATtrolTM). Detection of HSV-2 with plasmid DNA at target concentrations 2.5E1 was 100%. For VZV, detection rates of 100% were observed at LOD challenge pools comprising 1x102 IU/ml (WHO) and 1.85x101 copies/ml (NATtrolTM). Detection of VZV with plasmid DNA at target concentrations 2.5x101 was 95%. For MPXV, detection rates of 100% were observed when challenged with LOD pools at 1.67x101 copies/ml respectively. Detection of MPXV with plasmid DNA at target concentrations 6.25x100 was 95%. Confirmation of clade II reporting for MPXV was determined using phylogenetic analysis. Conclusions Standardize of Seegene’s multiplex HSV-1, HSV-2, VZV, MPXV assay using traceable quantitated standard resulted in >95% detection rates of 6.17x100 copies/ml for HSV-1, 5.56x101 copies/ml for HSV-2, 1.85x101 copies/ml for VZV, and 1.67x101 copies/ml for MPXV respectively. A single multiplex PCR assay offers advantages for the simultaneous detection of HSV, VZV, and MPXV DNA in lesions specimens where clinical features present overlap and in patients whose clinical history is difficult to obtain.

B-281 Performance Characteristics Evaluation of the ARK Diagnostics Immunoassay for Xylazine/4-HydroxyXylazine in Urine

Abstract Background Xylazine exposure is currently common in some US cities, but routine laboratory testing is not available. We evaluated the ARK Diagnostics immunoassay for qualitative detection of xylazine/4-hydroxy Xylazine in urine, prior to its anticipated release as a Forensic Use Only assay. Evaluation of performance characteristics of the ARK assay were conducted at two university hospitals, using either the semi-quantitative application of the assay, as performed on the Roche Cobas 503 analyzer (Institution A), or the qualitative application of the assay, as performed on the Beckman Coulter AU480 analyzer (Institution B). Methods Xylazine (X) and 4-hydroxy Xylazine (4-OHX) were obtained from Cayman Chemical (Ann Arbor, MI). Pooled xylazine-free urine was spiked either with X or 4-OHX in the range of 0-2000 ng/mL. De-identified, to-be-discarded patient urine samples were obtained from among those submitted for routine drugs-of-abuse panel testing. X measurements on all samples were performed by LC-MS/MS; samples were segregated into X-NEGATIVE (X<10 ng/mL) and X-POSITIVE (X>=10 ng/mL). The ARK assay was conducted according to manufacturer’s instructions, either as a semi-quantitative assay (Institution A, Roche analyzer) or as a qualitative assay (Institution B, Beckman Coulter analyzer), with 10 ng/mL as the manufacturer-specified cutoff for ARK POSITIVE, using manufacturer-supplied calibration standards ranging from 0-500 ng/mL X. Results The ARK semi-quantitative analysis (Roche analyzer) showed essentially equivalent curvilinear response curves for either X or 4-OHX at concentrations below 1000 ng/mL; for the semi-quantitative ARK assay, we use “>1200 ng/mL” for X-ARK >1200 ng/mL. By mixing studies (Roche), there were neither positive nor negative interferences observed as assessed for common drugs of abuse or for common therapeutic drugs. The presence of hemoglobin, bilirubin or moderate lipemia were devoid of assay interference. Precision studies for manufacturer-supplied controls were as follows: intra-assay CVs were 6.9% for the NEGATIVE control (5.1±0.35 ng/mL) and 5.9% for the POSITIVE control (15.7±0.53 ng/mL) (n=20); interassay CVs were 7.8% for the NEGATIVE control (5.1±0.40 ng/mL) and 5.7% for the POSITIVE control (15.9±0.90 ng/mL) (n=20). For the qualitative ARK assay as performed on the Beckman analyzer, POSITIVE and NEGATIVE controls ran invariably according to their designations. For the semi-quantitative assay application (Roche analyzer): among 78 X-NEGATIVE samples by LC-MS/MS, there were 0% ARK-POSITIVE results (false-positive rate=0%); among 74 X-POSITIVE samples by LC-MS/MS, there was one ARK-NEGATIVE result (false-negative rate=1.4%); this sample (X=65 ng/mL) was found to have a high amorphous crystalline content, and was unable to be reanalyzed. For the qualitative assay application (Beckman Coulter analyzer): among 78 X-NEGATIVE samples there was one ARK-POSITIVE sample (false-positive rate=1.3%) for a sample with xylazine=8.8 ng/mL by LC-MS/MS, with undetectable 4-OHX (<10 ng/mL); among 74 X-POSITIVE samples, there were no ARK-NEGATIVE results (false-negative rate=0%). Conclusions The ARK xylazine immunoassay demonstrated acceptable analytical performance with respect to detection of xylazine in urine at 10 ng/mL. With additional consideration of the assay’s cross reactivity with the major xylazine metabolite, 4-OH-xylazine, the assay was judged to be highly suitable for routine use as a screening test for detection of xylazine exposure via urine testing.

B-123 Prediction of Opioid Use Duration in Post-Surgical Orthopedic Patients Using CYP2D6 Inhibitor Index and Routine Laboratory Markers

Abstract Background Hydrocodone, the most commonly prescribed opioid in the U.S., is typically used for pain management following surgery and is a known potential drug of abuse with non-negligible risk of addiction. Significant variability in patients’ response to hydrocodone therapy have been reported, owing to both iatrogenic and endogenous sources. The objective of this study is to evaluate the feasibility of predicting post-discharge hydrocodone use in patients who have undergone orthopedic surgery using patient demographics, genotyping, concurrently prescribed medications, and routinely collected laboratory test results. Methods Targeted genotyping was performed on each patient with genes known to affect hydrocodone pharmacokinetics or pharmacodynamics, including CYP2D6, CYP3A4, CYP3A5, CYP2B6, COMT, OPRM1, and ABCB1. An inhibition index for CYP2D6 was calculated by ranking concurrently prescribed medications as weak, moderate, or strong inhibitors of enzyme activity. Pain index, average hydrocodone dose per day during hospital stay, and CYP2D6 estimated activity scores based on allele functionality were included as predictors. In addition, a retrospective chart review of electronic hospital records was performed where basic metabolic panel and complete blood count results were screened within 10 days of each patient's surgery date. Two types of classification and decision tree algorithms were tuned and validated as prediction models using 5-fold cross validation, including a ‘Fast and Frugal Decision Tree’ (FFTree) and an extreme gradient boosting machine (xgBoost). Clinical predictive features were ranked according to the Shapley Additive Explanations (SHAP) values using the xgBoost model. Results Out of 79 total patients with hydrocodone use duration information, 25 were categorized as “Short” and 54 categorized as “Long” using a 1-week threshold. FFTree model selected the top three features of CYP2D6 inhibition index, blood sodium level, and blood creatinine level and obtained a sensitivity and specificity of 0.80 and 0.76, respectively. The xgBoost model, using the same three features, achieved a sensitivity and specificity of 0.872 and 0.628, respectively, an AUROC of 0.814, PRAUC of 0.912, net benefit of 0.359, and was well-calibrated with a Brier score of 0.161. Consistent with previously published results, the predictive capacity of all genotypes analyzed were unremarkable and consistently ranked as the least important features by the xgBoost model SHAP values, due to their low predictive value. Conclusions Both the FFTree and xgBoost models were able to adequately classify the patients according to a 1-week stratification criteria with good to excellent classification performance. Patients with larger CYP2D6 inhibition index were more likely to be classified as “Long” duration. Sodium and creatinine level, which may reflect hydration status and renal function, and therefore hydromorphone elimination rate, were key predictors of post-discharge hydrocodone use duration when combined with the CYP2D6 inhibition index. Further refinement of the proposed models and validation of model robustness and stability using external cohorts is necessary. These results may have implications for providers when prescribing hydrocodone for pain management, where the ability to risk-stratify patients according to their predicted probability of developing opioid use disorder is of clinical importance.

B-127 The Effect of Hemolysis on Potassium Measurement in a Community Setting: The Marching Error

Abstract Background Potassium is one of the most sensitive analytes to in-vitro hemolysis. To detect this error, modern clinical chemistry analyzers calculate the hemolysis index (HI) to estimate the degree of specimen hemolysis. Recently, Roche Diagnostics lowered the acceptable potassium HI limit from 100 to 20 and recommended laboratories avoid using specimens with an HI>20. The goal of this study was to determine a clinically acceptable HI cut-off for potassium at our community reference laboratory, relying on patient data from routine laboratory operation. Methods Plasma venous potassium, sodium, and HI test results from community patients measured on Roche cobas 8000 ISE and c701 modules between September 2022 to December 2023 were extracted from the Roche Infinity Middleware (n=1,101,897). Data was divided into groups based on HI which ranged from 0 to 300. The sample pool with the lowest level of hemolysis (HI≤10) was defined as the base group. Mean and standard deviation of potassium for each HI group was calculated and the difference in the mean between each group compared to the base group was calculated as both absolute and percent ΔK. Percent changes in critical values for both potassium and sodium as a function of hemolysis were calculated for each HI group. Measurement uncertainty (MU) for potassium was calculated using a top-down approach. Data were analyzed in Rstudio and Microsoft Excel. Results The vast majority of potassium specimens (83.8%) were stratified into the HI base group (HI ≤10) and 96.8 % had an HI ≤ 20, the cut-off recommended by Roche. The mean potassium level for each HI group increased as the degree of hemolysis in the specimens became more elevated. A MU-derived analytically significant shift of ΔK>0.1 mmol/L was observed for the bin HI 21-30. Depending on the employed total allowable error limit, clinically significant shifts in mean potassium levels were observed at HI bin 41-50 (RCPA: ΔK>0.2 mmol/L) or HI bin 101-150 (EFLM-derived reference change value: ΔK>10.1% and CLIA: ΔK>0.5mmol/L. The shift in patient potassium values seen as HI increased led to a change in critical results reporting frequencies. In the base group (HI≤10), 0.06% and 0.07% of results had low (<2.6 mmol/L) or high (>6.2 mmol/L) critical potassium values, respectively. When HI was 101-300, 0.00 and 15.7% of results had low or high critical potassium values. A similar comparison performed with sodium did not show the same shift in reported critical values. Linear regression of ΔK plotted vs HI produced the equation ΔK=0.0051xHI, validating the equation of Martinez-Morillo and Alvarez published previously using paired hemolyzed/non-hemolyzed potassium laboratory data. Conclusions In community patients, in-vitro hemolysis produced analytically significant errors at an HI of 20. Clinically significant errors occurred between an HI of 40-100. Past HI 100, mean ΔKs of 0.5-1.20 mmol/L were seen in our population. This shift in patient values as a function of hemolysis led to a change in critical result reporting, suggesting the generation of both factious critically high potassium results and the masking of critically low potassium results in our patient population.

Prevalence and risk factors of low bone mineral density in Chinese Han male patients with alcohol dependence.

To investigate the prevalence of low bone mineral density (BMD) along with its possible risk factors in male Han Chinese patients with alcohol dependence (AD). This retrospective, cross-sectional study included male patients with AD, classified into normal and low BMD groups according to bone densitometry T scores. Demographic and alcohol-related data, and routine laboratory parameters were compared between the two groups. Binary logistic regression analysis was employed to evaluate risk factors associated with low BMD, and correlations between the T-score and demographic, alcohol-related, and routine laboratory data were evaluated. Among a total of 107 patients with AD included in the study, the prevalence of low BMD was 70.09% (75/107). Patients with low BMD were older, consumed more alcohol daily, and had higher lactate dehydrogenase (LDH) and lower Ca2+ levels than patients with normal BMD. Regression analysis revealed that increased daily alcohol intake, low serum Ca2+ levels, high serum LDH levels, and comorbid hypertension was related to low BMD in patients with AD. Further correlation analysis revealed a positive association between T-score and serum Ca2+ levels. Increased daily alcohol intake, low serum Ca2+ levels, high serum LDH levels, and comorbid hypertension may be risk factors for low BMD.

HELLP syndrome and associated factors among pregnant women with preeclampsia/eclampsia at a referral hospital in southwestern Uganda: a cross-sectional study

BackgroundHemolysis Elevated Liver Enzymes Low Platelets (HELLP) syndrome, a complication of preeclampsia/eclampsia, is associated with severe maternal morbidity and mortality. In resource-limited settings, such as Uganda, gaps in routine laboratory assessments may lead to underdetection of HELLP syndrome. This study determined the prevalence and factors associated with HELLP syndrome among pregnant women with preeclampsia/eclampsia at Mbarara Regional Referral Hospital (MRRH), southwestern Uganda.MethodsA cross-sectional study was conducted at the high-risk ward of the MRRH from December 2022 to June 2023. Pregnant women diagnosed with preeclampsia or eclampsia were enrolled consecutively. Participants’ sociodemographic and clinical data were collected using an interviewer-administered questionnaire. The diagnosis of complete HELLP syndrome was made based on the Tennessee classification: aspartate aminotransferase enzyme ≥ 70 IU/L, platelet counts < 100,000 cells/µL, and serum lactate dehydrogenase enzyme ≥ 600 IU/L. We used multivariable modified Poisson regression analysis to determine factors associated with HELLP syndrome.ResultsA total of 129 participants with a mean age of 28 ± 6.6 years were enrolled in the study. The prevalence of HELLP syndrome was 18.6% (n = 24; 95% CI: 12.7–26.3%). Independent factors associated with HELLP syndrome were maternal age (adjusted prevalence ratio [aPR]: 4.96; 95% CI: 1.57–15.65; for mothers aged < 20 years compared to those aged 20–34 years), the presence of epigastric pain (aPR: 5.89; 95% CI: 1.41–14.63), and referral from other health facilities (aPR: 3.14; 95% CI: 1.27–7.72).ConclusionApproximately 2 of the 10 women who presented with preeclampsia or eclampsia had HELLP syndrome. It is more common among teenage mothers, those with a history of epigastric pain and those referred from lower health facilities. Incorporating routine laboratory testing for HELLP syndrome in the diagnostic protocol for preeclampsia or eclampsia, especially among adolescent mothers, those experiencing epigastric pain, and those referred from lower health facilities, could enhance timely detection and management of mothers with preeclampsia whose pregnancies are complicated by HELLP syndrome.

Costs and benefits of routine labs in hospital patients: iatrogenic anaemia and undiagnosed acute kidney injury

ImportanceGuidelines recommend avoiding unnecessary laboratory tests to minimise risks of anaemia in hospitalised patients as well as reduce costs, but there are costs to skipping routine labs including missing acute...

Use of NIR in COVID-19 Screening: Proof of Principles for Future Application.

The COVID-19 pandemic that affected the world between 2019 and 2022 showed the need for new tools to be tested and developed to be applied in global emergencies. Although standard diagnostic tools exist, such as the reverse-transcription polymerase chain reaction (RT-PCR), these tools have shown severe limitations when mass application is required. Consequently, a pressing need remains to develop a rapid and efficient screening test to deliver reliable results. In this context, near-infrared spectroscopy (NIRS) is a fast and noninvasive vibrational technique capable of identifying the chemical composition of biofluids. This study aimed to develop a rapid NIRS testing methodology to identify individuals with COVID-19 through the spectral analysis of swabs collected from the oral cavity. Swab samples from 67 hospitalized individuals were analyzed using NIR equipment. The spectra were preprocessed, outliers were removed, and classification models were constructed using partial least-squares for discriminant analysis (PLS-DA). Two models were developed: one with all the original variables and another with a limited number of variables selected using ordered predictors selection (OPS-DA). The OPS-DA model effectively reduced the number of redundant variables, thereby improving the diagnostic metrics. The model achieved a sensitivity of 92%, a specificity of 100%, an accuracy of 95%, and an AUROC of 94% for positive samples. These preliminary results suggest that NIRS could be a potential tool for future clinical application. A fast methodology for COVID-19 detection would facilitate medical diagnoses and laboratory routines, helping to ensure appropriate treatment.