Antibody Screening Test Research Articles

P-2203. High Rate of False Positives in Military Blood Donors Screening Positive for Hepatitis C Virus

Abstract Background While the overall rates of Hepatitis C virus (HCV) in military populations are low, positive post-donation screening represents the second most common indication for post-donation infectious deferrals in military blood donors. All donors who screen positive are permanently deferred from blood donation, regardless of follow-up testing in clinical laboratories. There is limited data on the follow-up evaluation of these blood donors. This study describes the confirmatory testing, access to appropriate subspecialty care, and treatment of blood donors who screened positive for HCV at a large military blood bank. Methods All military blood donors between 2017-2023 at the Armed Service Blood Bank Center-San Antonio were screened for HCV by both antibody tests and nucleic acid tests, with positive antibody screening tests confirmed with an enzyme-linked immunosorbent assay (ELISA). Donors who screened positive had their medical charts reviewed to determine demographic information, follow-up evaluation, and treatment rates. On follow-up clinical diagnostic tests, patients with positive antibodies were determined to true positives (TP) and those with negative antibodies were determined to be FP. Results Of the 100,182 blood donors during the study period, 37 (0.04%) screened positive for HCV, of which follow-up information was available for 27 (73%). Of these 27, only 12 (44%) of donors were found to be TP. TP donors were more likely to be older (median 22 [20-29.5] vs. 20 [18-22], p=0.05) and have higher rates of positive nucleic acid testing (58% vs. 0%, p=0.001) after blood donation (Table 1). There was no difference in linkage to both primary and subspecialty care for TP and FP (Table 2). Of the TP, 7 (58%) were viremic, 3 (43%) of which received anti-viral therapy and 4 (57%) were administratively separated. Conclusion While HCV is one of the most common infectious reasons for military service members who donate blood to be deferred from future donations, most positive screenings were FP. Future efforts should be made to re-enter these patients with FP screening tests back into the donor pool. Disclosures All Authors: No reported disclosures

A comparative study evaluating three line immunoassays available for serodiagnosis of equine Lyme borreliosis: Detection of Borrelia burgdorferi sensu lato-specific antibodies in serum samples of vaccinated and non-vaccinated horses

Diagnosis of equine Lyme borreliosis (LB), an infection caused by members of the Borrelia burgdorferi sensu lato complex (Bbsl), is challenging due to the nonspecific clinical signs of the disease and due to the variety of non-standardized serological tests. Specific vaccine-induced antibodies against LB, providing an effective protection against the infection, complicate the issue further. The standard for the detection of specific antibodies against Bbsl is a two-tier test system based on an enzyme-linked immunosorbent assay (ELISA) or indirect fluorescent antibody test (IFA) for antibody screening combined with a qualitative, highly specific immunoassay (e. g. line immunoassay (LIA)) for confirmation. In this study, three LIAs available for detection of antibodies in equine serum samples were evaluated and compared. A total of 393 serum samples of 131 horses with known serostatus were used. It included groups of non-vaccinated horses, immunized horses (vaccinations against LB on days 0 and 14), and horses that had received an initial immunization plus an additional booster on day 180. Sera were collected on days 0, 135 and 210 of the study. Results were compared considering the tests’ sensitivity, specificity, diagnostic outcome, and the operability of each test. Agreements of the diagnostic results among the LIAs were calculated for overall test results and single antigen-antibody-complex signal results. They are presented as inter-rater agreement and statistic reliability, represented by the Fleiss’ kappa coefficient. Agreement scores ranged from poor to moderate depending on group and time-point of blood sample collection. Depending on LIA used, deficiencies were observed in the form of non-sufficient sensitivity of antigen signals on the LIA strips (especially for outer surface protein A (OspA) or variable major protein like sequence expressed (VlsE)) or as an inappropriate test interpretation of the OspA signal. Operability of the three LIAs was equally user-friendly with minor variations. In two LIAs, test-evaluation was simplified by a supplied scanner and evaluation software. To improve functionality of available LIAs for equine serum samples it is advisable to adjust sensitivity and specificity of single test antigen signals and establish appropriate evaluation protocols.

Acute hemorrhagic leukoencephalitis with a positive transfusion-related antibody screening test

Acute hemorrhagic leukoencephalitis with a positive transfusion-related antibody screening test

HEMOLYTIC DISEASE OF THE NEWBORN DUE TO UNRECOGNISED ANTI-Kpa ANTIBODY

Background: Kpa occurs in less than 2 percent of the Caucasian population. Antibody to this low frequency antigen causes mild to moderate delayed hemolytic transfusion reactions and hemolytic disease of fetus and newborn. Screening for antibodies to low frequency antigens such as Kpa is not routine, so sensitization is more difficult to diagnose. Case report: We present a case of hemolytic disease of the newborn due to anti-Kpa antibody unrecognised during regular considered first pregnancy. Results: Newborn, blood group 0 RhD positive, has been diagnosed with neonatal jaundice and positive direct antiglobuline test. Mother's screening test for irregular antibodies was negative three times during pregnancy. Elution was negative with screening red blood cells, but in identification using gel technology with cell's panels, anti-Kpa has been identified. Conclusion: Screening for antibodies to low frequency antigens such as Kpa is not routine, so immunisation to low incidence antigens is hard to diagnose, but very important. This case should alert us that there really is potential of antibodies to low incidence antigens to cause severe reactions. Keywords: Kell blood group system; Hemolytic disease of newborn; red cell alloimmunisation

RhD-negative red blood cells can be saved during liver transplantation in RhD-negative patients due to low risk of alloimmunization against RhD.

Transfusion demand is high in liver transplantation (LT), and thus RhD-positive (RhD+) red blood cell concentrates (RBCs) are sometimes given to RhD-negative (RhD-) patients. Due to immunosuppression, these patients rarely produce anti-D. We investigated the rate of anti-D formation in RhD- patients undergoing LT who were transfused with RhD+ RBCs as well as the number of transfused RhD- and RhD+ RBCs. RhD-type and transfusion history of all patients undergoing LT between 2010 and 2023 were reviewed retrospectively. In RhD- patients, who received RhD+ RBCs, the results of antibody screening test (indirect antiglobulin test and with papain-treated test cells) and direct antiglobulin test were evaluated. Five hundred and twenty-seven patients underwent 576 LT. Eighty-seven patients were RhD-, of whom 42 were transfused with RhD+ RBCs. In 34 of them, an antibody screening test result was available more than two weeks after the last RhD+ RBCs transfusion. In two of them, a transient, weak anti-D antibody was detectable, which disappeared in the further course. Overall, 1352 RBCs were transfused to the 87 RhD- patients, 543 of those were RhD+. Most RhD+ RBCs were provided to men and elder women. Transient weak anti-D occurred in two RhD- male patients during LT after transfusion of RhD+ RBCs without evidence for a hemolytic transfusion reaction. To save stocks of RhD- RBCs, early transfusion of RhD+ RBCs to RhD- men and women beyond the childbearing age should be considered during LT.

Coexistence of Celiac Disease and Allergic Wheat Sensitivity: An Observational Study of Daily Clinical Practice

Introduction: Although separate immunogenic mechanisms are involved, IgE-type sensitization to wheat and celiac disease (CD) may coexist. We observationally assessed the importance of this relationship in daily practice using CD and wheat sensitization screenings. Methods: Celiac antibody (CA) screening and food prick tests (FPTs) were requested simultaneously from patients who presented to the Allergy Clinic between January 2022 and December 2023 and had any complaint accompanied by CD symptoms/findings (non-celiac group). Patients with positive CA (CA+) underwent endoscopy. As another group, FPT results were recorded for patients previously diagnosed with CD following a gluten-free diet (celiac group). Results: In total, 169 patients (124 non-celiac and 45 celiac) were included in the study. Wheat prick positivity (WP+) was observed in 1 patient with CD. Among 65 WP+ patients without a CD diagnosis, 14 (20.3%) tested positive for CA+, and histopathology detected CD in 4 of these cases. Among the 59 WP– patients, 4 (8.8%) had CA+. The CA+ status of those with WP+ was significantly higher than those with WP– (p = 0.023). Conclusion: The 4 patients unaware of their CD exhibited WP+, with a higher rate of CA+ observed in the WP+ group. The association between WP+ and CA+ suggests that an impaired intestinal barrier may lead to simultaneous T helper 1 and 2 type inflammatory responses. Although different types of sensitization to the same food would not typically be expected, growing evidence indicates that this phenomenon does occur. Further studies are necessary to confirm these findings and to explore the underlying causes.

A-299 Assessment of a new miniaturized line blot system for fully automated serodiagnosis of Borrelia infections

Abstract Background Serodiagnosis of Lyme disease caused by Borrelia burgdorferi commonly affords the combination of a sensitive antibody screening test followed by confirmatory immunoblot analysis. We developed and evaluated a new immunoblot system enabling the multiparametric analysis of anti-Borrelia antibodies by means of miniaturized line blots in a fully automated microplate format. Methods The EUROMicroblots Anti-Borrelia (IgG and IgM, EUROIMMUN) are based on diagnostically relevant Borrelia-specific antigens. Diagnostic sensitivity was determined by analyzing 203 pre-characterized samples from patients with Lyme disease stratified by clinical picture and antibiotic treatment. Specificity was assessed using 168 sera from patients clinically diagnosed with rheumatic diseases. The reference range was analyzed using a control panel of 211 (IgG) and 210 (IgM) samples from healthy individuals, comprising 151 (IgG) and 150 (IgM) blood donors as well as 60 pregnant women (IgG, IgM). The Microwell Imager and EUROLineScan software (EUROIMMUN) were used for image acquisition and evaluation. Results Depending on the clinical category, the diagnostic sensitivity of the EUROMicroblots ranged from 68.0% in the early phase of infection to 100% (IgG/IgM combined) at a specificity of 86.9% (IgG) and 94.0% (IgM). The analysis of the panel of healthy control subjects revealed a prevalence of 10.9% (IgG) and 2.8% (IgM). Conclusions The new EUROMicroblot system enables high-throughput serodiagnosis of Borrelia infections due to the microplate format and automated processing and evaluation. Depending on clinical symptoms and treatment, the assays provide excellent diagnostic sensitivity and specificity for the detection of anti-Borrelia IgG and IgM.

Comparison of Safety and Cost of Cross-match Tests and Antibody Screening before Blood Transfusion in Patients Undergoing Orthopedic Surgery: A Cross-sectional Study

Introduction: Planning for blood request and balancing supply and demand are still contentious issues in hospitals and blood transfusion centers. This study aimed to compare the safety and cost-effectiveness of two pre-transfusion tests for red blood cells in patients undergoing orthopedic surgery. Method: In this descriptive-analytical cross-sectional study, patients undergoing surgery who required blood transfusion during the operation were included via convenience sampling method. The necessary information for this study was collected using a researcher-made checklist consisting of two parts: background information, blood bag information, and information related to potential complications. The cost estimation of the tests was also extracted using the records. The findings were analyzed using descriptive and inferential statistics with SPSS software (version 18), and the significance level was set at 0.05. Results: A total of 212 patients with a mean age of 44.98 years were included in the study. Cross-match was performed for 108 patients (50.9%), and antibody screening test was used for 104 patients (49.1%). Regarding complications after blood transfusion, at least one sign was observed in 12 patients (5.7%). Jaundice, fever, and itching were the most common symptoms. The cross-match to transfusion (C/T) ratio was higher than international standard criteria (5.25 vs. 2.5). Conclusion: The results of this study demonstrated that the safety and accuracy of both pre-transfusion methods were similar, and no significant difference was observed. However, the cross-match test was more cost-effective compared to the match antibody screening test.

Distribution and genotyping of hepatitis C virus (HCV) infection in Gansu province, China.

The distribution of common subtypes of hepatitis C virus (HCV) in Gansu province were analyzed. This information provided a theoretical basis for the selection of appropriate antiviral treatment regimens. We collected data on HCV antibody screening tests from 421,802 outpatients and inpatients at the Second Clinical Hospital of Lanzhou University from January 2018 to June 2022. Ribonucleic acid (RNA) viral load, HCV genotypes, and HCV quantification were analyzed retrospectively. The results of HCV positive detection rate, copy number, and genotype distribution were statistically analysed using SPSS 26.0. A total of 421,802 HCV antibody screenings were performed resulting in 4,558 positive cases (1.081%). In addition, 2,345 cases (1.302%) were positive with quantitative HCV antibodies in 180,157 outpatients and inpatients. Quantitative HCV virus RNA was further measured in 2592 outpatients and inpatients. There were 825 positive cases for HCV, with a positivity rate of 31.83%. High-sensitivity quantification of HCV-RNA was performed in 6538 patients, among which 1336 were HCV-RNA positive infections (positivity rate of 20.43%). Among the 1484 genotype tests, 4 genotypes and 10 subtypes were detected, including 4a, 1b, 2a, 2b, 3a, 3b, 6a, 6n, 1b/2a, and 2a/6a, with the majority of results from 2a (51.89%) and 1b (42.72%). The most prevalent genetic subtype in HCV-positive patients in Gansu was 2a, followed by 1b. In addition, 8 genotype subtypes appeared: 1a, 2b, 3a, 3b, 6a, 6n, 1b/2a and 2a/6a. Understanding the distribution of HCV genes in Gansu province is of significance for the optimization of virus treatment.

Prevalence of HTLV-1/2 infection in pregnant women in Central and South America and the Caribbean: a systematic review and meta-analysis

BackgroundHuman T-lymphotropic viruses (HTLV)-1 infection is endemic in many countries of Central and South America and Caribbean (CSA&C). Neither screening nor surveillance programs exist for HTLV-1/2 infection among pregnant women in this region. Neither in Western nations with large migrant flows from HTLV-1/2 endemic regions. MethodsSystematic review and meta-analysis of the prevalence of HTLV-1/2 infection among CSA&C pregnant women. We included studies searching EMBASE, PubMed/MEDLINE, Scopus, and Web of Science from inception to February 15, 2023. This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. ResultsWe identified a total of 620 studies. Only 41 were finally included in the meta-analysis. Most studies (61.0%) were from Brazil and Peru (14.6%). The total number of participants was 343,707. The pooled prevalence of HTLV-1/2 infection among CSA&C pregnant women was 1.30% (95% CI: 0.96-1.69) using anti-HTLV-1/2 antibody screening tests. There was a high heterogeneity (I2 = 98.6%). Confirmatory tests gave an HTLV-1 infection rate of 1.02% (95% CI: 0.75-1.33). ConclusionsThe prevalence of HTLV-1/2 infection among CSA&C pregnant women is 1.3%, most cases being HTLV-1. This rate is greater than for other microbial agents regularly checked as part of antenatal screening (such as HIV, hepatitis B, or syphilis). Thus, HTLV-1/2 antenatal testing should be mandatory among CSA&C pregnant women everywhere.

Presence of anti-RBC antibodies correlates with parasitaemia and once-infected RBCs but not the extent of post-malaria haemolysis.

In a cohort of patients treated with oral artemisinin combination therapy for uncomplicated malaria, the presence of anti-red blood cell (RBC) auto-antibodies does not correlate with the extent of post-treatment haemolysis. Patients with positive antibody screening test on d14 had higher initial parasitaemia and a higher number of once-infected RBCs throughout follow-up.

The Challenge of Preoperative Panel Reactive Antibody Positivity in Parathyroid Transplantation.

Identifying suitable recipient criteria and matching recipients with appropriate donors are required to increase survival for parathyroid transplant. This study was undertaken to evaluate transplant survival rates while comparing preoperative panel reactive antibody positivity. The study included 14 hypoparathyroidism patients who presented to our clinic for parathyroid transplant. Preoperative ABO compatibility and negative cross-match tests were prioritized for recipient-donor matching, and panel reactive antibody screening tests were performed. During the 24-month follow-up, we evaluated medication use and serum calcium, phosphorus, and parathormone levels of patients. Preoperative panel reactive antibody positivity was assessed in 3 groups. The HLA class I-positive group (mean fluorescence intensity range, 179-1770) showed decreased medication use and stability in serum calcium levels. The HLA class IIpositive (mean fluorescence intensity range, 85-3959) showed decreased medication use by 25% to 50% and returned to their former prescription doses after 12 months. An opposite pattern was observed in 2 patients with panel reactive antibody positivity for both HLA classes (mean fluorescence intensity range, 462-2289), with 1 patient requiring medication for continuing symptoms and the other patient occasionally taking additional magnesium supplementation, despite decreased medication doses after 12 months. Serum calcium levels remained normal, and parathormone and phosphorus levels were elevated. Improving patient symptoms and having no requirement for intravenous calcium replacement are priorities, and monitoring serum levels is the next important step. Varied panel reactive antibody positivities and survival rates indicate a requirement, and each HLA class could require a proper limitation for the mean fluorescence intensity. Preoperative mean fluorescence intensity cut-off value should be <900. Higher mean fluorescence intensity values in panel reactive antibody screenings could increase risk of short-term graft survival after parathyroid transplant. Further studies should include immunological risk assessments by individualizing the outcome with donor-specific antibodies.

Лайм-кардит у підлітка (клінічний випадок)

In recent years, the number of registered cases of Lyme carditis has been increasing. Purpose - to increase the vigilance of clinicians in various fields of medicine regarding Lyme carditis and awareness of its clinical manifestations on the example of the following clinical case. An empirical, descriptive study of a clinical case of Lyme pericarditis in a child from an endemic area was conducted. The research was carried out in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the bioethical commission of the hospital. Patient consent was obtained. An analysis of the literature data of PubMed, Medscape, СDC was also carried out. Clinical case. The paper describes a clinical case of a teenager with manifestations of pericarditis as a complication of Lyme infection with manifestations of untreated erythema migrans several months after a tick bite. The appointment of non-steroidal anti-inflammatory drugs did not bring relief. Conclusions. Alertness to Lyme carditis is important in the diagnosis of infectious nosologies. Lyme carditis should be considered in the differential diagnosis in patients with signs of myocardial ischemia in children with bradycardia living in endemic areas. For differential diagnosis, a two-step serological blood test is required, especially the use of screening tests for antibodies to Borrelia by ELISA with further confirmation by Western blot analysis. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Risk factors for red blood cell alloimmunization in multi-transfused oncology patients at Moi Teaching and Referral Hospital, Kenya

Background : Multiple blood transfusions may result in the production of alloantibodies against one or more red blood cell antigens which might make it more challenging to execute subsequent transfusions. Despite age and gender being risk factors for transfusion and being associated with alloimmunization frequency, they are not routinely taken into account before transfusion. This study assessed red blood cell alloimmunization and its association with risk factors among multi-transfused oncology patients at Moi Teaching and Referral Hospital Cancer Centre, Kenya.&#x0D; Methodology : The study employed a cross-sectional study design and focused on multi-transfused oncology patients at the Moi Teaching and Referral Hospital Cancer Centre. A sample size of 162 was used in the study based on Fisher's exact test formulae and a consecutive sampling technique was applied. The gel-based antibody screening and identification were performed with "ID-Diacell I-IIIII®" panel cells. The frequency, mean, median, and dispersion of descriptive statistics were shown and the association between alloimmunization with the number of transfusions, age and sex were determined by Spearman's correlation analysis. Statistical significance was established at P&lt; 0.05 and statistical tests were run at a 95% level of significance.&#x0D; Results : This study established no association between alloimmunization and the number of transfusions (P= 0.753). There was also no association between alloimmunization and age (P= 0.159). However, there was a significant positive association between alloimmunization with gender (P= 0.01). The study had a 6.2% prevalent rate of red blood cell alloimmunization, females had a greater prevalent rate than male patients. Anti-E and anti-K were the most prevalent alloantibodies.&#x0D; Conclusion and Recommendation : There is a need to improve current blood grouping and cross-match practices in most Kenyan hospitals by performing antibody screening and antibody identification tests. This study suggests routinely assessing alloimmunization in patients getting several transfusions while taking gender into account.

Evorpacept-Induced Interference and Application of a Novel Mitigation Agent, Evo-NR, in Pretransfusion Testing

Introduction: Evorpacept is a CD47-blocking agent currently being developed for the treatment of various cancers. Interference by evorpacept in pretransfusion compatibility testing has been reported at limited plasma concentrations. Although various mitigation strategies have been proposed, none are practical. This in vitro study assessed evorpacept-induced interference at extended concentrations and investigated the capability of a novel mitigation agent, Evo-NR. Methods: Antibody screening tests were performed on evorpacept-spiked plasma with (anti-E and anti-Jka) or without alloantibodies at evorpacept concentrations up to 2,000 μg/mL using manual gel cards and automated analyzers. Evorpacept-coated red blood cells (RBCs) (rr [ce/ce], Fy[a+b−], S−s+) were tested by direct antiglobulin testing (DAT) and antigen typing using anti-Fyb and anti-S reagents at indirect antiglobulin testing (IAT) phase. Evo-NR was used to resolve the interference in plasma and RBC samples. Flow cytometry was used to assess the mitigation effects. Results: Evorpacept-spiked plasma showed panreactive interference in antibody screening tests using manual gel cards (2+ to 3+) and automated analyzers (4+). A carryover effect was also observed in the automated analyzers. The use of a 3- to 6-fold molar excess of Evo-NR effectively resolved the interference in the plasma and enabled accurate alloantibody identification. Although the reduction in evorpacept binding to RBCs was identified via flow cytometry, Evo-NR was incapable of resolving the serologic interference observed in DAT and antigen typing at IAT phase. Discussion: Evorpacept showed constant panreactivity and a carryover effect at high concentrations. Evo-NR successfully resolved the interference in the plasma samples and could be considered a practical and efficient mitigation solution. Implementation of Evo-NR has the potential to support RBC transfusion for patients undergoing evorpacept treatment.

SAT318 Autoimmune Polyglandular Syndrome II In A Young Female With Severe Weight Loss, DKA, And Psychiatric Features

Abstract Disclosure: G. Wintermyer: None. C. Arcilla: None. E. Villanueva: None. Autoimmune polyglandular syndrome type II (APS II) is a rare combination of multiple endocrine diseases. The most common associated diseases are diabetes type I, Hashimoto thyroiditis, and Addison’s disease. Most patients present with nonspecific symptoms, typically in adulthood. Here we describe a 19-year-old female with APS II:A 19-year-old female with history of depression presented to hospital with severe nausea, vomiting and chest pain. She was diagnosed with pneumomediastinum secondary to hyperemesis. The symptoms were assumed secondary to ziprasidone that she was then taking.Patient experienced 20-pound weight loss in a very short period. Patient went to ED again for excessive weight loss. She was diagnosed with DKA for the first time and was admitted to ICU (Glucose level above 500 mg/dL and A1C 7.1%). After discharge, patient came to the endocrinology clinic for management of type 1 diabetes. Her BMI was 17 kg/m2. Vital signs were normal. Since the start of insulin therapy, patient gained weight and her BMI increased to 18.5 kg/m2.Patient was clinically well for about 1 year. She had periodic complete blood tests, including TSH, A1C and CMP, all of which remained normal with A1C’s of 6.3% and 6.8%. Approximately 1 year later, her TSH was 8.230 uIU/mL and free T4 was 0.92 ng/dL with subsequent TPO of 27 IU/mL. Diagnosis of Hashimoto’s hypothyroidism was made, and she was started on levothyroxine.Even though patient was on treatment for hypothyroidism, she complained of fatigue. CMP showed sodium 133 mEq/l and bicarbonate 17 mEq/l. Celiac antibodies presented negative. Cortisol AM and ANA were ordered. Before patient had the lab tests done, she was admitted to psychiatric hospital due to psychosis and bizarre behavior. Shortly after, patient was transferred to medical hospital for nausea and vomiting. Her labs were as follow: Sodium 100 mEq/l, Potassium 6.5 mEq/l, Bicarbonate 12 mEq/l, anion gap 19, Glucose 157 mg/dl. Stat cortisol and ACTH were 1.3 mg/dL and 332 pg/mL, respectively.Patient was admitted to ICU with adrenal crisis. She was started on Fludrocortisone and IV Hydrocortisone and IV fluid for hyponatremia. She was discharged from hospital with resolution of her psychiatric features. Her final diagnosis was APS II. She was started on Fludrocortisone 0.1, Hydrocortisone 20 mg in the morning and 10 mg at night.Clinicians should keep this disease in mind when assessing a patient who has presented with other autoimmune endocrinologic diseases, especially diabetes type I or adrenal insufficiency. Frequent visits, vital checks, CMP, and antibody screening tests including GAD antibodies, anti-adrenal antibodies, and TPO antibodies help in diagnosing this syndrome earlier.Clinicians also should be mindful of psychiatric features in a patient. They should try to rule out medical causes before diagnosing a patient with psychiatric disease as profound hyponatremia can cause acute psychosis. Presentation: Saturday, June 17, 2023

A-315 Pregnant Women Showed Lower Incidence Rates of False-positive Treponemal Antibody Screening Results When Compared with Nonpregnant Women and Men at an Appalachian Academic Medical Center

Abstract Background Screening for syphilis infection is recommended for all pregnant women and any adult or adolescent with increased risk for infection. Many clinical labs have adopted the reverse syphilis serology testing algorithm, that employs an automated and high-throughput treponemal antibody test as the initial screen followed by a non-treponemal antibody test to confirm all reactive samples. For specimens with discordant results, a second treponemal antibody test is used as the adjudicator. Syphilis serological tests can have false-positive results, causing discordant results between screening test and confirmatory test and complicating result interpretation. It is controversial from the literature whether pregnancy is a cause of false-positive results. This study is to determine the incidence rate of false-positive treponemal screening results among pregnant and nonpregnant patients, and to assess whether false-positivity is associated with pregnancy and age. Methods This is a retrospective study of sequential results from two treponemal antibody screening tests, including BioPlex 2200 Syphilis Total immunoassay between May 2020 and Jan 2022, and Alinity i Syphilis TP assay between Feb 2022 and Nov 2022. For each screening test, the incidence rates of false-positive results were calculated based on the reverse algorithm criteria and compared among pregnant women, nonpregnant women and men. The age differences between patients with false-positive results and patients with nonreactive results were also evaluated. Results Overall, 0.32% of 9 575 samples tested by Alinity assay showed false-positive results not confirmed by RPR or TP-PA. This is significantly lower (P &amp;lt; 0.01) than 0.60% of 14 983 samples observed for BioPlex assay. However, the lower incidence rate of false-positive results for Alinity assay relative to the Bioplex assay is only observed in pregnant women (0.18% vs 0.44%, P &amp;lt; 0.01) and nonpregnant women (0.32% vs 0.71%, P = 0.06), but not in men (0.68% vs 0.63%, P = 0.81). For both assays, male patients with false-positive results had an older median age than those with nonreactive results, and female patients showed the opposite trend, although statistical significance was only observed in nonpregnant women for Bioplex assay (median [IQR], 25 [19–35] vs 30 [22–43], P = 0.047). For both assays, pregnant women had lower incidence rates of false-positive results than nonpregnant women, although the differences did not reach statistical significance without age adjustment (Bioplex assay: 0.44% vs 0.71%, P = 0.07; Alinity assay: 0.18% vs 0.32%, P = 0.26). When age is adjusted, binary logistic regression analysis showed that pregnant women had significantly lower incidence rates of false-positive results relative to nonpregnant women for both assays (BioPlex assay: P = 0.049; Alinity assay: P &amp;lt; 0.01). Conclusion Although the incidence rates of false-positive results in BioPlex and Alinity treponemal antibody screening tests were overall within a low range, a significantly lower rate was observed for Alinity assay in pregnant women but not in men. For both assays, pregnant women showed a significantly lower incidence rate of false-positive results in comparison with nonpregnant women after age adjustment.

The impact of pretransplant suspected HLA antibody on the long-term outcome of the graft kidney: A retrospective cohort study

IntroductionThe preoperative examination of kidney transplantation includes HLA antibody screening to initially determine the presence of preexisting donor-specific antibody (DSA) that mediates hyperacute rejection. Recipients with positive HLA antibodies require further HLA specificity analysis to type the antigen and determine the antigen mismatches between the donor and recipient. However, recipients with suspected antibodies would have no further HLA specificity analysis. It is unclear whether suspected HLA antibodies would affect renal graft function. This study aimed to explore the impact of pretransplant suspected HLA antibody on the long-term outcome of the graft kidney and thus determine the necessity of routinely performing the HLA specificity analysis in recipients with suspected HLA antibodies preoperatively. MethodsThis is a single-center retrospective cohort study. 179 kidney transplant recipients (KTRs) were included and further divided into HLA antibody-negative group (Group 1) and HLA antibody-suspected groups (Group 2) based on the result of the pretransplant HLA antibody screen test. And the antibody-suspected group was further divided into a low-mismatched group (Group A) and a high-mismatched group (Group B) according to the HLA specificity analysis. We tracked the renal function indexes, biochemical indexes, and posttransplant adverse events within 5 years after transplantation and explored the necessity of further HLA specificity analysis in recipients with pretransplant suspected HLA antibodies. ResultsThere was no statistically significant difference in demographics between HLA antibody-negative group and HLA antibody-suspected groups. At 5 years of follow-up, the KTRs in HLA antibody-negative group had significantly higher eGFR levels, lower serum creatinine levels, and less urinary protein compared to those in antibody-suspected group. Meanwhile, the KTRs in low-mismatched group also had significantly higher eGFR levels, lower serum creatinine levels, and less proteinuria compared to those in high-mismatched group. Correlation analysis showed that the age of KTRs, urinary protein levels and the load capacity of HLA mismatches were associated with eGFR levels of KTRs at 5 year posttransplant. ConclusionKTRs with suspected HLA antibodies before kidney transplantation have worse graft function than the preoperative HLA antibody-negative recipients in the long-term posttransplant follow-up. The specific load capacity of HLA mismatches, the age of the recipient and the urinary protein was found to be negatively correlated with long-term posttransplant renal outcomes. It is necessary to undergo further HLA specificity analysis for recipients with suspected HLA antibodies in HLA antibody screen test to explicit HLA mismatches and improve long-term posttransplant outcomes.

Characterization of antigenic preparations for anti-HCV screening tests: Issue of test performance

Screening for anti-HCV antibodies is often subject to contradiction between different laboratories due to the use of tests from different manufacturers. In this study, we have proceeded to the identification of the various screening tests for anti-HCV antibodies with the main concerns of the characterization of each brand according to its principle, its antigenic preparation, and its evaluation in relation to the PCR RNA HC Positive and Negative samples. Our results identified thirty-two anti-HCV tests, of which 90.7% of the anti-HCV antibody detection tests had the following principles: simple liquid phase immunochromatography and solid support, the other tests, their principles were based either on the immunobolt (3.125%) or on sandwich immunochromatography (6.25%). 22 tests (68.75%) had no specification of the antigen preparation 9 tests mentioned (28.125%) recombinant proteins and only 1 test (3.125%) Recombinant proteins + synthetic peptides The correspondence was the antigen preparation, and its composition was such that 12 tests of recombinant protein preparations consisted of 8 tests contained the core, NS3, NS4 and NS5 proteins; 1 tests nucleocapsid and non-structural proteins. The evaluation of the anti-HCV tests presents on the Lubumbashi market, it turns out that the antigenic preparation tests: Core, NS3, NS4, NS5, meet the description of third-generation anti-HCV tests, because they consist of core antigens, NS3 and NS4 antigens combined and incorporated an NS5 epitope, showed significantly improved performance in terms of sensitivity and specificity.

Piperacillin-tazobactam induced immune hemolytic anemia led to increased renal impairment and eventual death from multiple organ failure in a patient with hypertensive nephropathy: case report and literature review

BackgroundPiperacillin is one of the most common drugs that cause drug-induced immune hemolytic anemia, but a complete description of the serological features and course of the disease is rare. This study completely describes the serological characteristics and course of a patient with hypertensive nephropathy who developed drug-induced immune hemolytic anemia and worsened renal function during repeated administration of piperacillin-tazobactam.Case presentationA 79-year-old male patient with hypertensive nephropathy who developed severe hemolytic anemia and worsened renal function during intravenous piperacillin-tazobactam anti-infective treatment due to lung infection. Serological tests showed that the result of the direct antiglobulin test for anti-IgG was positive (4 +) and anti-C3d was negative, and the irregular red blood cell antibody screening test was negative. Plasma samples collected at different times from 2 days before to 12 days after the discontinuation of piperacillin-tazobactam administration were incubated with piperacillin solution and red blood cells of O-type healthy blood donors at 37 °C, IgG piperacillin-dependent antibodies were detected, and the highest titer was 128. However, no tazobactam-dependent antibody was detected in any plasma samples. Therefore, the patient was diagnosed with piperacillin-induced immune hemolytic anemia. Although blood transfusion and continuous renal replacement therapy were given, the patient died of multiple organ failure 15 days after the administration of piperacillin-tazobactam was stopped.ConclusionThis is the first complete description of the disease course and serological changes of piperacillin-induced immune hemolytic anemia, which is bound to help deepen the understanding of drug-induced immune hemolytic anemia and draw profound lessons from it.