Normal Urine Research Articles

Integrated proteomics reveals enrichment of oxidative stress and inflammatory proteins in the urine and stone matrix of calcium oxalate stone formers.

Nephrolithiasis is a multifactorial disease associated with urinary and matrix proteins that become a focal point of research for diagnostic and preventative strategies. The functional relevance of these proteins in lithogenesis, along with their origins and impacts, remains a major subject of ongoing lithogenic research. Here, an integrated analysis was done on multiple proteome datasets compiled from various studies of normal urine (NU), urine from calcium oxalate stone formers (SFU), and calcium oxalate stone matrix (SM). Functional annotation and network analysis revealed the profound enrichment of proteins associated with oxidative stress and inflammation only in the stone-related samples (both "SFU but not NU" and "SM but not NU" cohorts). The oxidative stress and inflammation-related proteins were most abundant in the "SM but not NU" cohort and had higher proportions in the "SFU but not NU" cohort than the "NU only" cohort. KEGG pathway analysis corroborated such observation and highlighted the inclusion of proteins in the complement and coagulation pathways, particularly in SM. The findings of this study inform some mechanistic insights into the roles of calcium oxalate stone-related proteins and may help develop effective prevention and treatment strategies for nephrolithiasis.

P-780. Ultrasensitive Detection of Urine LAM for All Kinds of Tuberculosis Utilizing Optofluidic Single-Molecule Counting Technology

Abstract Background Sputum is an imperfect yet widely used sample type for the diagnosis of tuberculosis (TB). Children and people living with HIV (PLHIV) are often unable to produce sputum, testing with culture and nucleic acid amplification tests is costly and has long turn-around time, and sputum cannot be used for diagnosis of extrapulmonary TB. Lipoarabinomannan (LAM) in urine is an established TB biomarker, but currently available tests have poor sensitivity (limit of detection [LoD] ∼250 pg/mL and as low as 13% clinical sensitivity) and are only approved for use in PLHIV. Fluxus’ single-molecule counting technology combines integrated optics and microfluidics on a single chip-based system and achieves ultrasensitive detection of biomarkers. We have developed a prototype urine LAM assay utilizing the Fluxus technology and evaluated the preliminary analytical and clinical performance. Methods LoD and dynamic range were determined in buffer and urine by spiking cultured LAM (cLAM) into both matrices. LoD and limit of quantification (LoQ) for endogenous LAM urine (uLAM) were calculated after diluting a urine sample from an individual living with HIV and confirmed TB and with known concentration of uLAM as quantified by MesoScale Diagnostics (MSD) electrochemiluminescence. Dilution linearity and spike recovery activity were measured by spiking cLAM in buffer and normal urine, respectively, in concentrations ranging 0.01–100 ng/mL. Crossreactivity with Mycobacterium smegmatis LAM was evaluated with pooled normal urine. Results LoDs for cLAM in buffer and urine were 0.32 pg/mL and ∼1 pg/mL, respectively, with a >5-log dynamic range. LoD and LoQ for uLAM were ∼2 and ∼10 pg/mL, respectively. Linearity was acceptable across the range 0.01–100 ng/mL with a mean 102% recovery (range 86%–134%) and mean spike recovery was 106% (range 80%–130%). No crossreactivity with M. smegmatis LAM was observed. Conclusion Fluxus’ LAM assay, powered by single-molecule counting technology, detects cLAM and uLAM at pg/mL concentrations and with a broad dynamic range. There was minimal matrix effect across the dynamic range of the assay and no crossreactivity to M. smegmatis LAM. An ultrasensitive LAM assay has the potential to significantly increase the diagnostic yield and to expand the use of LAM testing to all kinds of TB. Disclosures Cathy Le, BS, Fluxus, Inc.: Stocks/Bonds (Public Company) Tiffany Truong, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Gipshu Dave, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Justin Nguyen, BS, Fluxus, Inc.: Stocks/Bonds (Public Company) Phuong-Uyen Tran, BS, Fluxus, Inc.: Stocks/Bonds (Public Company) Niamh Nolan, MS, Fluxus, Inc.: Advisor/Consultant Renee Tobias, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Valerie Brachet, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Frank Zaugg, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Peter Wagner, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Johanna Sandlund, MD, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company)

Diagnosing alkaptonuria-related nephropathy with urine albumin analysis.

Homogentisic acid (HGA) accumulation in alkaptonuria (AKU) causes injuries in various organs including the kidney. We present a case of a 9-year-old girl initially diagnosed with AKU-related nephropathy due to proteinuria found in her urine analyses. Despite 1month of ramipril treatment, the patient's proteinuria progressed, and as a result, kidney biopsy and nitisinone treatment were planned. In addition, we controlled her proteinuria with urine albumin measurement. After finding a normal urine albumin level in the 24-h urine sample, we realized that the patient was misdiagnosed with proteinuria because of HGA interference with urine protein level measurement using benzethonium. The patient's treatment for kidney injury was canceled. Urine albumin level was measured as normal 2months later, confirming proteinuria was a false-positive test result. AKU-related nephropathy should be evaluated with urine albumin measurement instead of protein. In this way, the complication risk of unnecessary interventions and pharmacotherapies can be avoided.

Unraveling diabetic kidney disease: insights from single-cell RNA sequencing.

The incidence of diabetic kidney disease (DKD) is rising annually. Diabetes leads to structural damage and dysfunction in the kidneys, clinically manifesting as progressive proteinuria and declining renal function, ultimately resulting in end-stage renal disease (ESRD). Recent findings have identified a subset of DKD known as normoalbuminuric diabetic kidney disease (NADKD), characterized by normal urine albumin levels but reduced renal function. These complex clinical presentations and underlying pathophysiology challenge traditional diagnostic and treatment approaches. Single-cell RNA sequencing (scRNA-seq), a novel experimental technique, is employed to analyze gene expression in renal tissue, blood, and urine from DKD patients, enhancing our understanding of tissue function, cellular interactions, and disease progression. This approach facilitates early screening and personalized management of DKD.

MINIMAL CHANGE DISEASE IN PEOPLE LIVING WITH HIV: A CASE REPORT AND REVIEW OF THE LITERATURE.

Various glomerular diseases are associated with human immunodeficiency virus (HIV) infection. However, the incidence of minimal change nephrotic syndrome has scarcely been reported. We describe a patient with a stage 4 HIV infection complaining of swelling in his face, hands, feet, genitals and an enlarged abdomen. Urinalysis revealed +3 proteins with normal urine sediment, and 2.1 g protein was found in the 24-hour analysis. Renal ultrasound showed bilateral glomerulopathies with hyperechoic and cortical thickening, a normal kidney size, and ascites. Kidney biopsy revealed acute tubular injury without HIV-associated nephropathy (HIVAN) features. The patient was treated with salt restriction, diuretics, captopril, methylprednisolone, and combined ART for 2 weeks and showed clinical improvement. Two weeks after the remission, the patient came to the outpatient department with a history of a 3-day cough with rust-colored sputum, fever, malaise, and shortness of breath. The lung auscultation revealed bilateral rhonchi and the chest x-ray result suggesting pneumonia. The patient was diagnosed with sepsis associated with healthcare-associated pneumonia but was not willing to be hospitalized and passed away at home. This study is limited to single-case nature and the possibility of sampling error. However, this case encourages further study in the field of HIV-associated renal diseases in providing clear recommendation in the management in special population.

Utility of Urine Dipstick Testing in Pediatric Appendicitis: Assessing its Role in Identifying Complicated Cases and Retrocecal Appendicitis.

Diagnosing appendicitis in children remains a challenge, and the role of urine dipstick is controversial. This study aimed to evaluate the association between abnormal urine dipstick results and appendicitis, particularly appendicitis severity and appendix position. A prospective cohort study was conducted from 2017 to 2021 at a tertiary hospital in Sweden. Children aged ≤ 15 years with suspected appendicitis were included. Logistic regression was used to assess associations between abnormal urine dipstick results and sex, age, peritonitis, body temperature, C-reactive protein, complicated appendicitis, and appendix position. A total of 311 children with suspected appendicitis were included, with 193 (62%) diagnosed with appendicitis. Among these, 80 (41%) had complicated appendicitis. There was no difference in appendicitis rate between children with positive and normal urine dipstick results. Among children with appendicitis, 119 (62%) had positive urine dipstick results: 49% ketones, 29% erythrocytes, 23% protein, 19% leukocytes, and 2% nitrite. Multivariable analysis revealed that female sex (adjusted odds ratio: 2.41 [95% confidence interval, CI: 1.21-4.80], p = 0.013), retrocecal appendicitis (aOR: 2.39 [95% CI: 1.18-4.84], p = 0.015), and complicated appendicitis (aOR: 2.27 [1.01-5.13], p = 0.015) were significantly associated with abnormal urine dipstick results. Sensitivity and specificity of positive urine dipstick for complicated appendicitis was 56% (95% CI: 45-67%) and 64% (95% CI: 54-73%), respectively, with an area under the curve of 0.62 (95% CI: 0.54-0.70). Limitations in this study include potential unmeasured confounders such as hydration status and urinary tract infections. Abnormal urine dipstick results are common in children with appendicitis. Urine dipstick might help identify cases of complicated and retrocecal appendicitis.

Indications and Outcomes of Fetal Cystoscopy for Lower Urinary Tract Obstruction: A Comprehensive Review.

Fetal lower urinary tract obstruction (LUTO) encompasses a spectrum of rare congenital anomalies affecting the fetal urinary system, leading to significant morbidity and mortality. This condition, arising from various anatomical anomalies such as posterior urethral valves (PUV), urethral atresia, and cloacal malformations, disrupts normal urine flow, resulting in secondary complications such as pulmonary hypoplasia and renal impairment. Current management strategies, including fetal vesicoamniotic shunting (VAS) and fetal cystoscopy, aim to alleviate obstruction and mitigate associated risks. While VAS has been a longstanding intervention, fetal cystoscopy presents a promising alternative by enabling direct visualization and targeted treatment of urinary tract obstructions. However, fetal cystoscopy is not without challenges, including technical complexities and risks associated with invasive procedures. This review explores the rationale, indications, technical considerations, outcomes, and future innovations of fetal cystoscopy in managing LUTO. It highlights the critical role of accurate diagnosis, patient selection, and procedural expertise in optimizing fetal and maternal outcomes. Despite existing challenges, ongoing advancements in technology and clinical practice hold the potential for further enhancing the safety and efficacy of fetal cystoscopy, underscoring its evolving role in prenatal care.

Analysis of urine pH and specific gravity in pasture sheep

AbstractUrine pH and specific gravity represent the routine objectively verifiable parameters in urinalysis. Urinalysis is presently an underutilised analytical tool in ovine medicine but holds the same potential for predictive, diagnostic and prognostic use in sheep as it does in human and small animal medicine. Urine pH and specific gravity were measured as a health screening tool to ascertain normal physiological ranges in sheep on free-range summer pastures with free access to drinking water. Both sexes, different ages and various breeds including Dorper, Karakul, Damara and cross-breeds were recruited into the study to investigate possible sources of variation. Experimental animals were selected through stratified random sampling using farm records from a population of 69 rams, 135 ewes and 115 lambs. Samples of urine were collected from 60 rams, 60 ewes and 60 lambs by free catch following induction of micturition by transient apnoea. Urine pH was measured by a pH metre whilst urine specific gravity was evaluated with an optical refractometer. The urine pH ranged from 6.81 to 9.08, with a mean of 8.52 ± 0.02 (se). Only one animal had a urine pH value below the existing reference level (7.4–8.5). Concurrent abnormalities of the urine in dipstick analysis included proteinuria and glucosuria. Urine specific gravity varied from 1.003 to 1.050 with a mean of 1.021 ± 0.001 (se). Four sheep, all of them lambs, had urine-specific gravity values above the existing reference level (1.015 to 1.045). The high urine specific gravity was associated with diverse pathological findings including proteinuria, pyuria and glucosuria as well as the presence of urine sediment. Urine pH was influenced by gender and breed and specific gravity by age. The results affirmed that sheep naturally produce alkaline urine and aciduria points to an underlying pathological problem. An association between high urine specific gravity and systemic/urinary system disorders was evident in lambs. Isosthenuria and hyposthenuria were frequently encountered in healthy adult sheep and were considered indices of positive water balance rather than renal dysfunction. Collated data confirmed existing reference levels but revised the upper limit of normal urine pH to 9 instead of 8.5, and the lower limit of normal urine specific gravity to 1.003 instead of 1.015.

Management of children with kidney injuries of various severity: a series of clinical observations

BACKGROUND: Kidney injury takes approximately 1–5% of all urinary tract and abdominal cavity injuries. Children blunt trauma amounts more than 90% of all kidney damages. Kidney injury is always followed by pain in the lumbar region and abdomen as well as by hematoma and hematuria. Serious renal injuries in children are more often accompanied by stable vital functions and normal general urine analyses compared to adults. Such patients require dynamic observation and instrumental examination so as to determine further curative strategy. CLINICAL CASE DESCRIPTION: This article describes three clinical cases of kidney injury in children. In the first case, ultrasound examination and computed tomography revealed contusion changes in the kidney, subcapsular hematoma and renal parenchyma rupture without damage of the collecting system. Due to clinical findings, ultrasound and computed tomography examination, conservative management was prescribed to one patient, while for the other two with renal parenchyma rupture — surgery. One of these patients had malformation — a gap between the upper and lower segments of the double kidney. Such malformation could aggravate the injury. CONCLUSION: The present series of clinical observations is an example of managing children with kidney injuries of varying severity. Depending on the damage severity, conservative management or surgical tactics are chosen by specialists.

Identification of Potential Diagnostic Markers for Depressive Disorders using Urinary Biomarkers of N-Methylnicotinamide and Hippuric Acid

Introduction: The diagnostic methodology for depressive disorders, relying on symptom clusters, has inherent limitations in ensuring heterogeneity levels. Consequently, this presents a notable risk of inevitable diagnostic errors in mental health assessments. Therefore, advocating for objective diagnostic approaches through empirical testing in clinical settings becomes crucial for individuals dealing with depressive disorders. This study aims to identify the effectiveness of urine as a diagnostic support for depressive disorders using the N-Methylnicotinamide and Hippuric Acid biomarkers. Methods: This study used 13 urine samples from patients with depressive disorders and 13 normal urine samples. It used ELISA methods with observational analytic and cross-sectional designs. Results: The results showed that the N-methylnicotinamide biomarker had a relationship with depressive disorders with a correlation value of 0.867, while hippuric acid obtained a correlation value of 0.692. Besides, the N-Methylnicotinamide and Hippuric Acid biomarkers showed differences in the urine of depressive disorder and normal patients with significance values of 0.000 and 0.001 for the N-Methylnicotinamide and Hippuric Acid biomarkers, respectively. In addition, the Relative Operating Characteristics curve analysis showed that these two biomarkers had good sensitivity and specificity values in assisting the diagnosis of depressive disorders. N-methylnicotinamide has a sensitivity of 92.3% and a specificity of 100%, while hippuric acid has a sensitivity of 76.9% and a specificity of 84.6%. Conclusions: Significant differences in the biomarkers of N-methylnicotinamide and hippuric acid in the urine of depressed patients compared to normal patients. Therefore, these biomarkers can be the empirical laboratory methods to support the diagnosis of depressive.

2D Fe/Co-MOF/SOX cascade reactors for fast noninvasive detection of sarcosine level in prostate cancer urine

Sarcosine plays a key role in screening for early prostate cancer. However, the several already reported peroxidase mimics immobilized with sarcosine oxidase (SOX) utilized to detect uriary sarcosine still have some limitations such as complex synthesis process, using of expensive heavy metals to mimic enzyme activity and long color development time. Herein, an inexpensive peroxidase-like 2D Fe/Co-MOF nanosheet was prepared by a simple solvent modulation method. The resultant 2D Fe/Co-MOF nanosheets have strong peroxidase activity, with its Vmax value for H2O2 of 15.3 × 10-8 M/s, being 1.76 times that of HRP. Then, using the 2D Fe/Co-MOF as a peroxidase model for anchoring natural SOX to construct 2D Fe/Co-MOF/SOX , which can act as a cascade reactor for detection of sarcosine. Considering the above properties, a platform for the detection of sarcosine was built based on a colorimetric method. Because of presence of the high ratio of Fe2+ caused by the electron transfer from Co2+ to Fe3+, large specific surface area and plentiful active sites, 2D Fe/Co-MOF/SOX with TMB (3,3′,5,5′-tetramethylbenzidine) colorimetric reagent could have fast color development and can be applied conveniently and fastly in an early screening tool for prostate cancer patients. The sarcosine could be quantified by peroxidase activity with a detection range of 1–400 μM and a limit of detection (LOD) of 0.324 μM. More importantly, the average sarcosine concentration of 21.367 μM and 1.871 μM was detected in patient’s and normal urine (n = 5), respectively, which showed an excellent screening effect and a great potential in early prostate cancer.

7752 Navigating Hypercalcemia in Pregnancy: A Case Report

Abstract Disclosure: J. Gabbay: None. S. Steinmetz-Wood: None. Introduction: Primary hyperparathyroidism (PHPT) in pregnancy is rare but presents many diagnostic and therapeutic challenges. Prompt diagnosis and treatment are important due to associated maternal and fetal risks, however evaluation of urine calcium to differentiate from Familial Hypocalciuric Hypercalcemia (FHH) becomes less reliable due to physiologic changes in pregnancy, sestamibi scans. CT scans require radiation, parathyroidectomy introduces surgical risk, and medical alternatives like bisphosphonates can interfere with fetal skeletal development. Clinical Case: A 24-year-old woman who presented to the emergency room for progressive nausea and abdominal pain was found to be pregnant with elevated serum calculated calcium to 11.4 mg/dL (2.84 mmol/L). She had a history of renal stones, longstanding hypercalcemia of unknown etiology and a remote family history of parathyroid “issues”. Follow up laboratory work showed a PTH of 75.8 pg/ml (8.04 pmol/L) with an elevated 24-hour urine calcium and a low 25OH vitamin D. Given her history of kidney stones and overt symptoms it was our clinical judgement that this was not a case of FHH. She was started on IV fluids twice weekly. After an unrevealing neck ultrasound, an MRI neck showed a 7 mm lesion along the posterior aspect of the left thyroid suggestive of a parathyroid adenoma. Sestamibi scan was avoided due to the risks of radiation to the developing fetus. Given the presumptive diagnosis of parathyroid adenoma, the lack of response to aggressive hydration, and the maternal and fetal risks of hypercalcemia during pregnancy, parathyroidectomy was pursued in her second trimester. Intra-operative inspection and biopsy showed the lesion to be only a lymph node. She underwent 4-gland exploration and the left inferior parathyroid gland, which appeared abnormal and enlarged, was removed. The intra-operative PTH dropped only from 98 to 80 (10.4 to 8.5 pmol/L). She otherwise had an unremarkable hospital course and at discharge her calcium was normal with an undetectable PTH, which can be an expected finding in pregnancy. On follow up she was feeling well with sustained normocalcemia and low PTH levels. Given the age at which her hyperparathyroidism started, she was referred to genetics for further evaluation. Clinical Lessons/Conclusion: There were significant biochemical and radiological limitations in the management of this case. Normally an inappropriately normal PTH with elevated serum calcium and normal urine calcium/creatinine clearance ratio confirms the diagnosis of PHPT, however in pregnancy it should be noted that FHH could also present with normal or elevated urine calcium due to absorptive hypercalciuria in pregnancy. Additional clinical history and reasoning was needed for management as well as a skilled surgeon, where preoperative localization was limited and was not ultimately helpful. Presentation: 6/2/2024

7510 Use Of Tumor Markers And Surgery In The Management Of Medullary Thyroid Cancer During Pregnancy

Abstract Disclosure: M. Garver: None. C. Vaz: None. Introduction: Thyroid cancer is the second most diagnosed cancer during pregnancy, predominantly differentiated thyroid malignancies. [1] MTC during pregnancy is rare and challenging to manage due to its aggressive nature. We describe the successful diagnosis and management of MTC during pregnancy. Clinical Case: A 28 yo woman presented with a rapidly growing neck lump for 2 months with an associated unintentional 10lb weight loss and without compressive symptoms. She had no history of childhood radiation exposure or family history of thyroid cancer. Physical exam revealed a hard L lobe thyroid nodule without palpable lymphadenopathy. The patient was 5 weeks pregnant at the time. A neck US revealed a 4.2x2.7x2.0 cm L solid isoechoic thyroid nodule with punctate echogenic foci and microcalcifications. The nodule was classified as TIRADS 4 and ATA high suspicion. FNA noted Bethesda IV with positive IHC stains for chromogranin and calcitonin. Afirma MTC classifier was positive, confirming diagnosis of MTC. At 7 weeks gestation, calcitonin was markedly elevated at 3508 pg/mL (n <5 pg/mL), CEA 29.5 ng/mL (n <2.5 ng/mL) and calcium 10.3mg/dL (8.6-10.2mg/dL). Plasma normetanephrines were elevated to176 pg/mL (n <148 pg/mL) with normal metanephrines 28 pg/mL (n <57 pg/mL) and normal 24-hour urine metanephrines. CT neck revealed 3.2x2.8cm L thyroid nodule without cervical lymphadenopathy. Due to pregnancy status, additional imaging to assess for metastatic disease was deferred until after delivery. Genetic testing did not identify mutations within the thyroid cancer panel including APC, CHEK2, DICER1, MEN1, PRKAR1A, PTEN, RET, SDHB, SDHD, and TP53. The patient underwent total thyroidectomy with neck dissection at 19 weeks gestation without complication. Two weeks postoperative Calcitonin was 2 pg/mL(n <5 pg/mL) and CEA was undetectable. Conclusions: The effect of pregnancy on MTC is not well studied because of low incidence. Guidelines on the timing of surgery for MTC diagnosed during pregnancy are lacking. While evidence confirms that surgery can be safely postponed until after delivery for low risk differentiated thyroid malignancies, there is no consensus on timing of surgery for MTC. Given the aggressive nature of MTC, along with marked elevation of calcitonin and CEA in this case, surgery was performed in the 2nd trimester with excellent outcome. Data is conflicting on accuracy of calcitonin and CEA during pregnancy, with some reports suggesting falsely high levels due to pregnancy. The sharp decline in calcitonin and CEA 2 weeks postoperatively suggested these were truly elevated due to MTC and unaffected by pregnant status. We suggest that calcitonin and CEA be followed similar to non-pregnant cases with MTC. Resources: 1.Khaled, H. M., Lahloubi, N. A., & Rashad, N. (2016). A review on thyroid cancer during pregnancy: Multitasking is required. Journal of Advanced Research, 7(4), 565–570. Presentation: 6/2/2024

8790 A Case Of Ectopic Cushing’s Syndrome Secondary To Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH)

Abstract Disclosure: T. Goettemoeller: None. R. Lopez Fanas: None. K. Cedeno: None. A. Manavalan: None. Introduction: Ectopic Cushing’s syndrome is a rare disease accounting for <20% of cases of endogenous Cushing’s syndrome. DIPNECH is a poorly understood lung disease characterized by abnormal proliferation of neuroendocrine cells in the bronchial mucosa. It can be a precursor to pulmonary carcinoid tumors and has rarely been associated with ACTH production. Clinical Case: A 70-year-old female with intellectual disability and hypertension presented with diffuse edema and weakness. Examination was notable for hypertension, anasarca, and hirsutism. In addition to hypokalemia and metabolic alkalosis, hypercortisolism was observed: random serum cortisol - 50.1 ug/dL, late-night salivary cortisol - 1.72 mcg/dL (normal < 0.09 mcg/dL) and 24-hour urine free cortisol - 1,845.9 mcg (normal: 4.0 – 50.0 mcg/24h). Cortisol level remained > 25 ug/dL after high-dose dexamethasone suppression test. Ketoconazole was initiated and titrated to achieve normal 24-hour urine free cortisol levels and spironolactone was added to manage hypokalemia. An MRI of the sella and pituitary was unremarkable while an abdomen and chest CT identified a 2.5 cm well-circumscribed right middle lobe pulmonary nodule and mild thickening of the bilateral adrenal glands. A gallium-DOTATATE scan revealed a 2.1 cm right middle lobe pulmonary nodule with mildly increased uptake. A transbronchial biopsy of the right middle lobe nodule confirmed a carcinoid tumor. Immunohistochemistry (IHC) staining was positive for CHR, SYN, CD56, and AE1/3. Ki-67 stain showed a low proliferative index. A right middle lobectomy was performed with pathology revealing two typical carcinoid tumors measuring 2.8 and 0.7 cm each, with multiple carcinoid tumorlets and foci of neuroendocrine cell hyperplasia consistent with DIPNECH. IHC staining for ACTH was positive in the carcinoid tumors and tumorlets. Four days after surgery, AM cortisol was 8.1 ug/dL and potassium levels and blood pressure normalized off ketoconazole and spironolactone. The patient was discharged, but was readmitted a month later for anasarca, lethargy, hypokalemia, and metabolic alkalosis. A recurrence of Cushing’s syndrome was confirmed, and medical therapy was resumed. A chest CT revealed post-surgical changes. Her course was complicated by an aspiration event, septic shock, PEA arrest, resuscitation, and intubation. The patient’s care was ultimately transitioned to hospice. Conclusion: Florid Cushing’s syndrome due to ectopic ACTH production associated with DIPNECH is an exceedingly rare condition. Early recognition and treatment are crucial to prevent the numerous complications that may arise, and close follow-up after tumor removal is critical to ensure continued remission has been achieved. Presentation: 6/1/2024

6891 Exclusive Normetanephrine Secreting Pheochromocytoma In A Young Male

Abstract Disclosure: E. Askar: None. H. Moran: None. IntroductionPheochromocytomas and paragangliomas arise from chromaffin cells and produce excessive catecholamines. Hypertension is their primary clinical symptom. they differ in their catecholamine secretory phenotype; paragangliomas typically secrete norepinephrine, while pheochromocytomas typically secrete epinephrine. Here, we present a case 21-year-old male with pheochromocytoma with elevated norepinephrine but normal epinephrine levels.Case presentationA 21 -year-old male with no past medical history presented with episodes of palpitations, sweating, and elevated blood pressure. He also reported abdominal pain. On admission, his blood pressure was 143/92 mmHg, pulse was 71/min, respiration was 16/min, and oxygen saturation was 100% in room air. The rest of physical exam was not significant. His electrolyte panel was normal. Computed tomography (CT) abdomen and pelvis with contrast was performed and showed a right adrenal mass measuring 4.9 x 4.0 x 6.5 cm which is predominantly hypoattenuating (approximately 30 Hounsfield units) with thick nodular rim of enhancement. Hormonal workup showed normal serum testosterone, DHEA-S, AM cortisol, ACTH, aldosterone, plasma metanephrine, and urine metanephrine, but profoundly high plasma normetanephrine 3641.6 (0.0-210.1) pg/mL. His 24-hour urinary normetanephrine was elevated at 14874 (80-440) ug/24hr, confirming a pheochromocytoma. The high norepinephrine level in the setting of normal epinephrine raised suspicion for Von Hippel Lindau (VHL). He was started on alpha and beta blockage and had laparoscopic removal of the right adrenal gland. The pathology report confirmed the diagnosis of pheochromocytoma confined to right adrenal. The patient was then referred for genetic testing. Conclusion: Pheochromocytoma can be a part of familial disorders, although being sporadic in nature most of the time. As demonstrated in our case, the hallmark of pheochromocytoma associated with VHL is nearly exclusive normetanephrine secretion and a high ratio of normetanephrine to metanephrine. Confirmation and testing of genes aid in proper monitoring and follow-up. The preferred course of treatment is radical resection. Presentation: 6/2/2024

8790 A Case of Ectopic Cushing’s Syndrome Secondary to Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH)

Abstract Disclosure: T. Goettemoeller: None. R. Lopez Fanas: None. K. Cedeno: None. A. Manavalan: None. Introduction: Ectopic Cushing’s syndrome is a rare disease accounting for <20% of cases of endogenous Cushing’s syndrome. DIPNECH is a poorly understood lung disease characterized by abnormal proliferation of neuroendocrine cells in the bronchial mucosa. It can be a precursor to pulmonary carcinoid tumors and has rarely been associated with ACTH production. Clinical Case: A 70-year-old female with intellectual disability and hypertension presented with diffuse edema and weakness. Examination was notable for hypertension, anasarca, and hirsutism. In addition to hypokalemia and metabolic alkalosis, hypercortisolism was observed: random serum cortisol - 50.1 ug/dL, late-night salivary cortisol - 1.72 mcg/dL (normal < 0.09 mcg/dL) and 24-hour urine free cortisol - 1,845.9 mcg (normal: 4.0 – 50.0 mcg/24h). Cortisol level remained > 25 ug/dL after high-dose dexamethasone suppression test. Ketoconazole was initiated and titrated to achieve normal 24-hour urine free cortisol levels and spironolactone was added to manage hypokalemia. An MRI of the sella and pituitary was unremarkable while an abdomen and chest CT identified a 2.5 cm well-circumscribed right middle lobe pulmonary nodule and mild thickening of the bilateral adrenal glands. A gallium-DOTATATE scan revealed a 2.1 cm right middle lobe pulmonary nodule with mildly increased uptake. A transbronchial biopsy of the right middle lobe nodule confirmed a carcinoid tumor. Immunohistochemistry (IHC) staining was positive for CHR, SYN, CD56, and AE1/3. Ki-67 stain showed a low proliferative index. A right middle lobectomy was performed with pathology revealing two typical carcinoid tumors measuring 2.8 and 0.7 cm each, with multiple carcinoid tumorlets and foci of neuroendocrine cell hyperplasia consistent with DIPNECH. IHC staining for ACTH was positive in the carcinoid tumors and tumorlets. Four days after surgery, AM cortisol was 8.1 ug/dL and potassium levels and blood pressure normalized off ketoconazole and spironolactone. The patient was discharged, but was readmitted a month later for anasarca, lethargy, hypokalemia, and metabolic alkalosis. A recurrence of Cushing’s syndrome was confirmed, and medical therapy was resumed. A chest CT revealed post-surgical changes. Her course was complicated by an aspiration event, septic shock, PEA arrest, resuscitation, and intubation. The patient’s care was ultimately transitioned to hospice. Conclusion: Florid Cushing’s syndrome due to ectopic ACTH production associated with DIPNECH is an exceedingly rare condition. Early recognition and treatment are crucial to prevent the numerous complications that may arise, and close follow-up after tumor removal is critical to ensure continued remission has been achieved. Presentation: 6/1/2024

7331 A Rare Case Of Familial Hypoparathyroidism

Abstract Disclosure: N. Sekhon: None. K.Z. Win: None. Background: Autosomal dominant hypoparathyroidism disorders are very rare and mostly asymptomatic. We present an interesting case of autosomal hypoparathyroidism with a new variant of gene defect on genetic analysis. Case: A 66-year-old female was referred to the endocrinology clinic for familial hypoparathyroidism and calcium oxalate nephrolithiasis. She had onset of seizures at age 16. She was diagnosed with hypocalcemia and hypoparathyroidism at age 30 when she had her first episode of nephrolithiasis. She had recurrent nephrolithiasis and lithotripsies, ultimately developing chronic kidney impairment that was at stage 3b at the time of evaluation. Renal Ultrasound revealed bilateral nephrolithiasis, and nephrocalcinosis. There was a history of hypoparathyroidism in her father, paternal uncle, and son. Her medications included calcium carbonate-vitamin D3 600-400 mg-unit oral 2 tablets daily and calcitriol 0.5 mcg daily. The pertinent physical examination finding was a short stature with height 4’11” and calluses in fingers. Her recent serum chemistry showed calcium 8.8 mg/dL (reference range 8.3 - 10.6 mg/dL), PTH < 6.3 pg/mL (reference range 18.4 - 80.1 pg/ mL), and phosphorus 3.3 mg/dL (reference range 2.4 - 5.5 mg/dL). 24 hr urine calcium was 96 mg (reference range 50-300 mg/24h). She was treated with hydrochlorothiazide for nephrolithiasis but was discontinued due to hypokalemia. We performed genetic testing that resulted positive for CASR NM_001178065.1 with heterozygosity and damaging missense predictions inherited as autosomal dominant or recessive. Discussion: The calcium-sensing receptor (CaSR) has an important role in calcium homeostasis by regulating parathyroid hormone (PTH) secretion and urinary calcium excretion. Familial hypoparathyroidism disorders are divided into Autosomal dominant hypocalcemia (ADH) type 1 and Autosomal dominant hypocalcemia (ADH) type 2. ADH1 is caused by an activating mutation of calcium-sensing receptor (CASR). The estimated prevalence of ADH1 ranges from 1 per 70,000 to 3.9 per 100,000. It is characterized by mild to moderate hypocalcemia, hyperphosphatemia, hypercalciuria, and inappropriately low but detectable PTH levels. It can be associated with Bartter syndrome Type 5. ADH2 is due to mutations in the alpha subunit of the G protein G11 (Gα11). Our patient had classic symptoms of hypocalcemia including short stature, seizures, kidney stones and its sequelae. Her 24-hour urine analysis showed inappropriately normal urine calcium with low normal serum calcium, undetectable serum PTH, and normal phosphorus. Our patient’s genetic analysis revealed a heterozygous defect in gene CASR with DNA variants c.2564G>A with damaging missense predictions. There is no such variant reported or listed in the ClinVar database. To our knowledge, this is the first such case of an autosomal dominant hypoparathyroidism with this gene defect. Presentation: 6/1/2024

7686 A Case Of A 66-Year-Old Male With Systemic Macrocytosis Complicated By Osteoporosis

Abstract Disclosure: J.M. Gri: None. M. Hillhouse: None. P. madhavan: None. Background: Osteoporosis in men is underestimated and warrants investigation for secondary causes of osteoporosis. Systemic mastocytosis is a rare secondary cause of osteoporosis. Clinical Case: This is a 66-year-old male with a past medical history of severe persistent asthma, eczema, hypertension, GERD with esophagitis, basal cell carcinoma, and systemic mastocytosis (diagnosed in 2010). Family history was significant for lung cancer in both of his parents. Patient was first noted to have hyperpigmented skin lesions on his legs, trunk and upper extremities in the early 1990s. The spots were biopsied and he was diagnosed with urticaria pigmentosa in 1998. Due to persistent symptoms of facial flushing and soft stool, he was referred to Hematology and was started on antihistamines. He later underwent a bone marrow biopsy in 2010 which showed multifocal mast cell aggregates but normal trilineage hematopoiesis. He endorsed back pain shortly after his diagnosis and a DXA scan was completed. The DXA scan showed osteopenia of the spine T score of -1.8, BMD 0.999 mg/mm3 and normal bone density in bilateral hips. He had no history of fractures. He was started on alendronate and remained on the medication from 2012 to 2015. It was stopped due to intolerable symptoms of acid reflux and he required proton pump inhibitors. DXA scan in 2017 showed normal bone density of the hips and osteopenia of the lumbar spine (T score -1.2). DXA scan in 2022 showed a decrease in spine BMD by 6% (T score -1.8) from 2017 to 2022 but unchanged from 2010. Hip bone mineral density was normal but decreased by 10% since 2010 and by 6% since 2017. Labs obtained in May 2022 showed normal serum electrophoresis, normal urine calcium and creatinine ratio, calcium and vitamin D level and urine NTX of 41 nM BCE/mM (21-83) and bone specific alkaline phosphatase level of 31.5 U/L (15-41.3). After discussion with the patient, conservative management with calcium, vitamin D and exercise has been implemented along with close follow up. Should the patient’s bone turnover markers increase or fracture risk increase, additional antiresorptive therapy will be initiated. Conclusion: This case study highlights the importance of screening for osteoporosis in patients with systemic macrocytosis. As this patient was diagnosed with osteopenia at age 53, this case also emphasizes the importance of early screening in both women and men with this rare condition. Presentation: 6/3/2024

A-125 Difference Between the Results of Vitros® Dry Biochemistry and Wet Biochemistry with Kinetic Method in Diagnosing the Comorbidity of Lung Adenocarcinoma and Aacroamylasemia: Case Report

Abstract Background Amylase (AMY) is a biomarker that comes mainly from the pancreas and salivary glands. Macroamylasemia is a condition often accompanied by malignant tumors and clinical features that include: (i) recurrent abdominal pain, no abnormality in the salivary glands, serum amylase (AMY) level ≥2 to 3 times higher than the normal value and poor patient response to treatments for pancreatitis; (ii) normal serum creatinine and urea levels, increased serum AMY level, and urine AMY level within the normal range or slightly lower. Because macroamylasemia may cause abnormally increased serum AMY levels for a long period of time, misdiagnosis of pancreatitis and delayed diagnosis/treatment of the disease may occur. We report a case of lung adenocarcinoma with macroamylasemia that was co-diagnosed using wet chemistry with kinetic method and dry chemistry to measure AMY. Methods A 47-year-old male patient was previously diagnosed with “acute pancreatitis and lung infection” after initial admission to a local hospital with paroxysmal cough and abdominal pain without obvious cause. To further diagnose the patient, we determined the blood AMY level by using the wet chemistry with kinetic method and the Vitros® dry chemistry test, in addition to conducting a physical exam, abdominal and chest computed tomography (CT), and other lab tests. Two methods, calculation of amylase/creatinine clearance ratio (Cam/Ccr ratio) and protein precipitation by polyethylene glycol (PEG), were also performed to validate assumed interference by serum macroamylase (MAMS) in the wet chemistry method compared to the dry chemistry method, which has technology to capture large molecules and minimize the impact of interferents. MAMS is a high-molecular-weight AMY complex that is synthesized by normal serum AMY bound with macromolecular substances (eg, immunoglobulins and carbohydrates). Results The final diagnosis was a stage IIB cT3N0M0 adenocarcinoma of the upper lobe of the right lung and macroamylasemia. Symptoms and radiologic findings were atypical in terms of pancreatitis. Serum AMY was 2,178U/L when measured with the wet chemistry with kinetic method. When the specimen was re-tested with Vitros dry chemistry, the AMY level was 369 U/L. After precipitation with 25% PEG 6000 solution, the blood AMY level from wet chemistry decreased from 2395.1 U/L to 246.7 U/L, yielding a precipitation rate of 89.7%. Cam/Ccr ratio was calculated as 0.23% (<1%). The calculated PEG precipitation rate and Cam/Ccr ratio from this study were consistent with the ranges considered for macroamylasemia, which are ≥73% and Cam/Ccr ratio <1%, respectively. Conclusions High serum AMY levels do not necessarily indicate pancreatitis or parotitis; wet chemistry results can be impacted by the presence of serum macroamylase. Instead of relying solely on blood AMY in diagnosing acute pancreatitis, clinicians should also consider the correlations of blood AMY with urine AMY and blood lipase. In patients with prolonged blood AMY elevation but normal lipase and urine AMY, re-testing of AMY with a more interference-resistant methodology (e.g. Vitros dry chemistry) may be requested. Accordingly, Cam/Ccr ratio calculation and PEG precipitation can be performed to validate the diagnosis of macroamylasemia.

A-106 Determination of Urinary NGAL Reference Intervals from Specimens of Healthy Adult and Pediatric Individuals

Abstract Background Neutrophil gelatinase-associated lipocalin (NGAL) is a 25kDa protein implicated in multiple biological processes, including attenuation of apoptosis and differentiation of renal tubule epithelial cells and nephrons. NGAL is also produced and secreted by injured kidney tubule epithelial cells. As such, NGAL can serve as an early urinary biomarker for acute kidney injury (AKI). This multi-site, cross-sectional study aimed to establish reference intervals for urinary NGAL (uNGAL) in healthy pediatric and adult populations using a particle-enhanced turbidimetric assay. Methods Apparently healthy individuals, aged ≥ 3 months, were eligible for this study. Subjects with an active urinary tract infection (UTI) on the day of sample collection, acute kidney injury (AKI) or a history of AKI, stage 4 or 5 chronic kidney disease (CKD), known congenital anomalies of the kidney and urinary tract, known urothelial, urological, or kidney malignancies were excluded from the study. Subjects with uncorrected congenital heart disease, having undergone solid organ or bone marrow transplantation, receiving renal replacement therapy, and having undergone surgery (urologic, nephrectomy, or correction of congenital heart disease) were also excluded. A total of 688 subjects were screened, 677 were eligible, and 629 (91.4%) were considered evaluable per the protocol. The 59 excluded subjects were ineligible due to missing/incorrect information in the informed consent form, or not evaluable due to meeting exclusion criteria, mostly a positive UTI test. Urine samples were tested for NGAL on a Roche cobas® c501 analyzer in single determinations. Results Tables 1 and 2 describe the NGAL summary statistics and central 95% reference intervals by age and gender. Conclusions These data demonstrate the normal urine NGAL values in an apparently healthy pediatric and adult populations.