Serum Antibody Tests Research Articles

Screening for active COVID-19 infection and immunization status prior to biologic therapy in IBD patients at the time of the pandemic outbreak

Coronavirus disease 2019 has been recently classified as pandemic infection by the World Health Organization. Patients with inflammatory bowel disease (IBD) are invited to follow the national recommendations as any other person. It is unclear whether a more aggressive clinical course might develop in asymptomatic COVID-19 infected subjects during biological therapy and current evidence does not support treatment suspension. However, during pandemic, the start of treatment with immunosuppressive drugs and biologics should be postponed whenever possible and based on an individual risk assessment. When clinical conditions and the disease activity do not allow a treatment delay, before starting a biological therapy, screening of IBD patients for COVID-19 active infection by RT-PCR should be advisable, even in absence of clinical suspicion. Serum antibody testing, when available, could provide evidence of infection as well as identify patients already immune to the disease.

Local Outbreak of COVID-19 in Shunyi District Attributed to an Asymptomatic Carrier with a History of Stay in Indonesia - Beijing Municipality, China, December 23, 2020.

Summary What is known about this topic? Patients with coronavirus disease 2019 (COVID-19) infection can be categorized by severity: asymptomatic infection, mild illness, moderate illness, severe illness, and critical illness. The rate of transmission to a specific group of contacts (the secondary attack rate) may be 3–25 times lower from people who are asymptomatically infected than from those with symptoms. The incubation period is 2–14 days. What is added by this report? An individual with asymptomatic infection shed live virus that started a 42-case outbreak in Shunyi District of Beijing in December 2020. The individual had been quarantined for 14 days in a designated quarantine hotel in Fuzhou after entering China from Indonesia. During quarantine, he had 5 negative throat swab tests and 2 negative IgM serum tests. The investigation team determined that the incubation periods of 31 confirmed cases ranged from 2 to 23 days. What are the implications for public health practice? The frequency of nucleic acid testing should be increased for international entrants and people who are close contacts of confirmed COVID-19 cases. The investigation team recommend expanding sample types for nucleic acid testing to include anal swabs and residential environmental sampling; serum antibody testing can be used as a reference indicator. Parallel testing by two institutions at key points in time, such as the end of isolation, should be implemented.

Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal

Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We examined the spatial distribution of S. neurona exposure risk based on serum antibody testing and assessed risk factors for exposure in animals from California, Washington, British Columbia and Alaska. Significant spatial clustering of seropositive animals was observed in California and Washington, compared with British Columbia and Alaska. Adult males were at greatest risk for exposure to S. neurona, and there were strong associations with terrestrial features (wetlands, cropland, high human housing-unit density). In California, habitats containing soft sediment exhibited greater risk than hard substrate or kelp beds. Consuming a diet rich in clams was also associated with increased exposure risk. These findings suggest a transmission pathway analogous to that described for Toxoplasma gondii, with infectious stages traveling in freshwater runoff and being concentrated in particular locations by marine habitat features, ocean physical processes, and invertebrate bioconcentration.

Kinetics of SARS-CoV-2 specific IgM and IgG responses in COVID-19 patients

ABSTRACT The emerging COVID-19 caused by SARS-CoV-2 infection poses severe challenges to global public health. Serum antibody testing is becoming one of the critical methods for the diagnosis of COVID-19 patients. We investigated IgM and IgG responses against SARS-CoV-2 nucleocapsid (N) and spike (S) protein after symptom onset in the intensive care unit (ICU) and non-ICU patients. 130 blood samples from 38 COVID-19 patients were collected. The levels of IgM and IgG specific to N and S protein were detected by ELISA. A series of blood samples were collected along the disease course from the same patient, including 11 ICU patients and 27 non-ICU patients for longitudinal analysis. N and S specific IgM and IgG (N-IgM, N-IgG, S-IgM, S-IgG) in non-ICU patients increased after symptom onset. N-IgM and S-IgM in some non-ICU patients reached a peak in the second week, while N-IgG and S-IgG continued to increase in the third week. The combined detection of N and S specific IgM and IgG could identify up to 75% of SARS-CoV-2 infected patients in the first week. S-IgG was significantly higher in non-ICU patients than in ICU patients in the third week. In contrast, N-IgG was significantly higher in ICU patients than in non-ICU patients. The increase of S-IgG positively correlated with the decrease of C-reactive protein (CRP) in non-ICU patients. N and S specific IgM and IgG increased gradually after symptom onset and can be used for detection of SARS-CoV-2 infection. Analysis of the dynamics of S-IgG may help to predict prognosis.

Varicella-zoster virus-induced rhabdomyolysis: A case report and literature review

Infection is a possible cause of rhabdomyolysis. We describe the case of a 63-year-old male with malaise and erythematous papules on the right C5–C7 dermatomes, consistent with herpes zoster. Serum antibody and Tzanck tests of the skin lesion were positive. Increased serum creatine kinase (CK) and myoglobin levels and cola-colored urine indicated the development of rhabdomyolysis. Acute kidney injury was also observed. After excluding other possible predisposing factors, the patient was diagnosed with varicella-zoster virus (VZV)-induced rhabdomyolysis. Extracellular volume with alkalized fluids and topical acyclovir was administered. While CK levels declined to normal by day 13, the renal function was not restored. The skin lesion crusted by day 8 and scaled off gradually by day 13. Our case and literature review highlighted the necessity for systemic antiviral treatment and that poor VZV infection control could lead to irreversible kidney injury. In addition, systemic acyclovir should be administered carefully due to its complication of nephrotoxicity.

Lyme Arthritis and Clinical Judgment.

* Abbreviation: EIA — : enzyme-linked immunoassay When a child presents with acute arthritis, the immediate question is whether it is “septic” (acute bacterial) arthritis, which, in addition to antimicrobial treatment, may need surgical washout to prevent permanent damage to the joint. This can be problematic in areas in which Lyme disease is endemic because Lyme arthritis, which does not require surgical washout and typically is subacute, can at times present like septic arthritis.1 In this issue of Pediatrics , Nigrovic et al2 address the question of whether invasive procedures (diagnostic arthrocentesis and surgical washout) can be avoided in patients who have Lyme arthritis by relying on the result of a C6 enzyme-linked immunoassay (EIA) for serum antibodies against Borrelia burgdorferi . The standard approach to diagnose Lyme arthritis is a 2-tier test for serum antibodies. The first-tier test typically is an EIA that uses antigens of sonicated whole B burgdorferi organisms to measure the quantity of the patient’s antibodies (immunoglobulin M and immunoglobulin G combined) against B burgdorferi . However, an EIA result may be positive from cross-reactive antibodies. Consequently, if the EIA … Address correspondence to Eugene D. Shapiro, MD, Department of Pediatrics, Yale School of Medicine, PO Box 208064, 333 Cedar St, New Haven, CT 06520-8064. E-mail: eugene.shapiro{at}yale.edu

Highly sensitive nested PCR and rapid immunochromatographic detection of Babesia bovis and Babesia bigemina infection in a cattle herd with acute clinical and fatal cases in Argentina.

Bovine babesiosis is a tick-transmitted haemoparasitic disease caused by Babesia bovis and B. bigemina affecting cattle of tropical and subtropical regions around the world. Pathogens are transmitted by the tick vector Rhipicephalus microplus displaying a widespread distribution in northeastern Argentina. The disease is characterized by significant animal morbidity and mortality resulting in considerable economic loss. In this study, B. bovis and B. bigemina infection was investigated in a cattle herd of 150 adult bovines of pure Braford breed raised in a tick-hyperendemic field using molecular and serum antibody tests. A highly sensitive nested polymerase chain reaction (nPCR) assay targeting a species-specific region of the apocytochrome b gene resulted in direct B. bovis and B. bigemina detection in 27.3% and 54.7% of bovines, respectively. A recently developed immunochromatographic strip test (ICT) based on recombinant forms of spherical body protein 4 and the C-terminal region of rhoptry-associated protein 1 showed that 71.3% and 89.3% of bovines were seropositive for B. bovis and B. bigemina, respectively. The mixed infection rate as observed by direct (19.3%) and indirect detection (65.3%) coincided with those expected, respectively. Importantly, four months after sampling, nine bovines of the studied herd showed clinical signs of bovine babesiosis of which six animals eventually died. Microscopic detection of infected erythrocytes in Giemsa-stained blood smears confirmed B. bovis infection. Our study demonstrates that although animals showed a relatively high and very high rate of immunity against infection with B. bovis (71.3%) and B. bigemina (89.3%) parasites, respectively, clinical cases and fatalities due to the infection with B. bovis were observed. It is proposed that the most adequate control measure in the studied epidemiological situation is to vaccinate animals to prevent losses and/or an outbreak of bovine babesiosis.

Stratification of gastric cancer risk using a deep neural network.

Background and AimStratifying gastric cancer (GC) risk and endoscopy findings in high‐risk individuals may provide effective surveillance for GC. We developed a computerized image‐ analysis system for endoscopic images to stratify the risk of GC.MethodsThe system was trained using images taken during endoscopic examinations with non‐magnified white‐light imaging. Patients were classified as high‐risk (patients with GC), moderate‐risk (patients with current or past Helicobacter pylori infection or gastric atrophy), or low‐risk (patients with no history of H. pylori infection or gastric atrophy). After selection, 20,960, 17,404, and 68,920 images were collected as training images for the high‐, moderate‐, and low‐risk groups, respectively.ResultsPerformance of the artificial intelligence (AI) system was evaluated by the prevalence of GC in each group using an independent validation dataset of patients who underwent endoscopic examination and H. pylori serum antibody testing. In total, 12,824 images from 454 patients were included in the analysis. The time required for diagnosing all the images was 345 seconds. The AI system diagnosed 46, 250, and 158 patients as low‐, moderate‐, and high risk, respectively. The prevalence of GC in the low‐, moderate‐, and high‐risk groups was 2.2, 8.8, and 16.4%, respectively (P = 0.0017). Three experienced endoscopists also successfully stratified the risk; however, interobserver agreement was not satisfactory (kappa value of 0.27, indicating fair agreement).ConclusionThe current AI system detected significant differences in the prevalence of GC among the low‐, moderate‐, and high‐risk groups, suggesting its potential for stratifying GC risk.

Oncologic Implications of Chronic Hepatitis C Virus Infection.

Chronic hepatitis C virus (HCV) infection increases the risk for several types of cancer, including hepatocellular carcinoma (HCC) and B-cell non-Hodgkin lymphoma, as primary and second primary malignancies. HCV-infected patients with cancer, particularly those undergoing anticancer therapy, are at risk for development of enhanced HCV replication, which can lead to hepatitis flare and progression of liver fibrosis or cirrhosis. Risk factors for HCV infection include injection drug use, blood transfusion, or solid organ transplantation before 1992, receipt of clotting factor concentrates before 1987, long-term hemodialysis, chronic liver disease, HIV positivity, and occupational exposure. Widely available direct-acting antivirals are highly effective against HCV and well tolerated. Identification of HCV-infected individuals is the essential first step in treatment and eradication of the infection. One-time screening is recommended for persons born from 1945 to 1965; screening is also recommended for persons with risk factors. Recently, a public health recommendation has been drafted to screen all adults age 18 to 79 years. Two oncology organizations recommend screening all patients with hematologic malignancies and hematopoietic cell transplant recipients, and a recently published multicenter prospective study supports universal HCV screening for all patients with cancer. HCV screening entails testing for anti-HCV antibodies in serum and, when results are positive, HCV RNA quantitation to confirm infection. Direct-acting antiviral therapy eradicates HCV in almost all cases. Virologic cure of HCV prevents chronic hepatitis and progression to liver fibrosis or cirrhosis. HCV eradication also decreases the risk of developing HCV-associated primary and second primary malignancies, and it may allow HCV-infected patients access to important cancer clinical trials. Patients with HCV-related cirrhosis require lifelong surveillance for HCC, even after viral eradication.

Correlation between the severity of peptic ulcer bleeding and Helicobacter pylori type

Objective To investigate the correlation between the severity of peptic ulcer bleeding (PUB) and the serum antibody typing of Helicobacter pylori (H.pylori). Methods From January 1, 2009 to December 31, 2018, at Guangzhou First People′s Hospital, 1 444 patients diagnosed with PUB and received H. pylori serum antibody test at the same time were enrolled and divided into high-risk group (324 cases) and low-risk group (1 120 cases) according to Forrest classification, and according to recurrent bleeding, the patients were divided into recurrent bleeding group (32 cases) and non-rebleeding group (1 412 cases). Serum H. pylori specific antibodies cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA) and urease were detected by protein array. The correlation between H. pylori positive rate, H. pylori type, PUB and rebleeding were analyzed. Chi-square test and logistic regression analysis were used for statistical analysis. Results Among 1 444 PUB patients, there were 709 patients with gastric ulcer bleeding (GUB) and 735 patients with duodenal ulcer bleeding (DUB). Previous history of peptic ulcer disease (odds ratio (OR)=1.501, P=0.006), the maximum diameter of ulcer over 2 cm (OR=2.484, P 0.05). According to H. pylori antibody type, H. pylori type Ⅰ infection was mainly in both high-risk group and low-risk group. The positive rate of H. pylori type Ⅰ strain of high-risk group was higher than that of low-risk group (67.28%, 218/324 vs. 60.45%, 677/1 120), and the difference was statistically significant (χ2=4.986, P=0.026). There was no statistically significant difference in the positive rate of H. pylori between GUB group and DUB group (68.41%, 485/709 vs. 68.57%, 504/735; χ2=0.005, P>0.05). Conclusions The infection of H. pylori is positively correlated with the severity of PUB, but not correlated with early ulcer rebleeding. H. pylori type Ⅰ is the main pathogenic strain of GUB and DUB, and CagA and VacA double positive strain is the most common strain. Key words: Helicobacter pylori; Urease; Peptic ulcer hemorrhage; Cytotoxin-associated gene A; Vacuolating cytotoxin A

Serum and CSF Anti-NMDAR Antibody Testing in Psychiatry.

The authors examined and compared the clinical presentation of CSF positive and negative N-methyl-d-aspartate receptor (NMDAR) antibody. The investigators performed a retrospective chart review of NMDAR-antibody-positive cases (serum or CSF) involving patients presenting to psychiatric services from 2010 to 2018 in Queensland, Australia. Presentation, progress, investigations, and efficacy of treatment are detailed. There were 24 serum or CSF NMDAR-antibody-positive cases and three equivocal serum results. High rates of prodromal cognitive deficits, catatonia, speech disturbance, and antipsychotic sensitivity were observed in the 16 CSF NMDAR-antibody-positive case patients and two CSF NMDAR-antibody-negative case patients, all evident before neurological deterioration with seizures, movement disorder, and autonomic disturbance occurring in the weeks following admission. The majority of these patients (N=17) were treated successfully with immunomodulatory therapy. The nine remaining patients, who were CSF NMDAR antibody negative or equivocal, did not demonstrate any of these features and improved with psychiatric care alone. These findings suggest that traditional psychiatric care may be appropriate for patients with isolated psychiatric symptoms who have positive serum NMDAR testing when CSF is negative and there are no key clinical features such as cognitive deficits, catatonia, speech disturbance, and antipsychotic sensitivity. However, if these key features are present, a trial of immunomodulatory treatment should be considered with repeated examination of CSF for neuronal antibodies.

The Accuracy of the Serum Antibody Test for Helicobacter pylori Infection among Junior High School Students

Objective: Recently, screening for Helicobacter pylori infection has been performed among children in Japan as a prevention strategy for gastric cancer. However, the diagnostic accuracy of the serum antibody test, using the ELISA-kit, for screening in children has not been confirmed, and it is unknown whether the cutoff value used for adults is appropriate for children. The aim of this study was to evaluate the accuracy of the serum antibody test for H. pylori infection for the mass screening of junior high school students in Japan. Subjects and Methods: H. pylori infection testing and eradication therapy in junior high schools began in the 2015 fiscal year for students in Yurihonjo and Nikaho cities, located in the Akita prefecture. The data of 410 students who underwent both stool antigen tests (SATs) and serum antibody test, between 2016 and 2018, were used for analysis. Students who had positive results on the SATs test were diagnosed with H. pylori infection. Results: The rate of H. pylori infection was 3.7% (15/410). The optimal cutoff of serum antibody for children was identified to be 5.4 U/mL, with this cutoff having an area under the curve of 0.94 (95% CI 0.83–1.00), specificity of 99.5% (95% CI 98.2–99.9) and sensitivity of 93.3% (95% CI 68.1–99.8), which was wide because of the small sample size. Conclusion: The accuracy of the serum antibody test may be enough for practical use in children 13–14 years old

Influence of Helicobacter pylori Infection and Atrophic Gastritis on the Gut Microbiota in a Japanese Population

Background: Although infection with Helicobacter pylori and subsequent atrophic gastritis modulate the gastric conditions, their relationship with the gut microbiota in ­Japanese population has not been clearly characterized. Methods: A cohort of 1,123 subjects who participated in a health survey was studied. Infection of H. pylori was defined by both serum antibody and stool antigen test. The presence and severity of atrophic gastritis were defined by serum levels of pepsinogens. The relative abundance of each bacterial species in fecal samples was calculated by using 16S ribosomal RNA amplification, and the composition ratios of bacterial taxa were evaluated using propensity score matching. Results: The abundance of 3 orders, 4 families, and 4 genera was significantly higher in H. pylori-infected subjects than in noninfected subjects (false discovery rate [FDR] <0.05). In H. pylori-infected subjects with severe atrophic gastritis, the abundance of the class Bacilli, order Lactobacillales, family Streptococcaceae, and genus Streptococcus was significantly higher than that in H. pylori-infected subjects without atrophic gastritis (FDR < 0.05). Conclusions: A significant increase in the relative abundance of several taxa was observed in gut microbiota of Japanese subjects with H. pylori infection. Among the subjects with severe atrophic gastritis, the increase in the genus Streptococcus is a remarkable characteristic.

Accuracies of Endoscopic Diagnosis of Helicobacter pylori-Gastritis: Multicenter Prospective Study Using White Light Imaging and Linked Color Imaging

Introduction: The diagnosis of Helicobacter pylori infection status with white light imaging (WLI) is difficult. We evaluated the accuracies of using WLI and linked color imaging (LCI) for diagnosing H. pylori-active gastritis in a multicenter prospective study setting. Methods: Patients who underwent esophagogastroduodenoscopy were prospectively included. The image collection process was randomized and anonymous, and the image set included 4 images with WLI or 4 images with LCI in the corpus that 5 reviewers separately evaluated. Active gastritis was defined as positive when there was diffuse redness in WLI and crimson coloring in LCI. The H. pylori infection status was determined by the urea breath test and the serum antibody test. Cases in which both test results were negative but atrophy or intestinal metaplasia was histologically confirmed were defined as past infections. The primary endpoint was the diagnostic accuracies of WLI and LCI, and the secondary endpoint was inter-observer agreement. Results: Data for 127 patients were analyzed. The endoscopic diagnostic accuracy for active gastritis was 79.5 (sensitivity of 84.4 and specificity of 74.6) with WLI and 86.6 (sensitivity of 84.4 and specificity of 88.9) with LCI (p = 0.029). LCI significantly improved the accuracy in patients with past infections over WLI (36.8 in WLI and 78.9 in LCI, p < 0.01). The κ values were 0.59 in WLI and 0.70 in LCI. Conclusions: LCI is useful for endoscopic diagnosis of H. pylori-active or inactive gastritis, and it is advantageous for patients with past infections of inactive gastritis.

Fulminant type 1 diabetes mellitus associated with Coxsackievirus type B1 infection during pregnancy: a case report

BackgroundFulminant type 1 diabetes is characterized by an intrinsic insulin deficiency resulting from the severe destruction of pancreatic β cells and it rapidly leads to ketoacidosis. However, the association between fulminant type 1 diabetes in pregnancy and specific viral infections has not been reported.Case presentationThe patient in this study was a 31-year-old Japanese woman, and at 30 weeks of pregnancy she was admitted with marked fatigue. Fetal bradycardia was noted, and the child was delivered by emergency cesarean section but was stillborn. The maternal blood sugar level was high (427 mg/dL), but the glycated hemoglobin value was 6.2%; therefore, fulminant type 1 diabetes was suspected. Serum antibody testing confirmed a Coxsackievirus B1 infection. The patient in this case had fulminant type 1 diabetes in pregnancy associated with Coxsackievirus B1.ConclusionThis case highlights that fulminant type 1 diabetes in pregnancy may be associated with Coxsackievirus B1 infection.

Association between infection with Helicobacter pylori and platelet indices among school-aged children in central Ethiopia: a cross-sectional study

ObjectivePrevious clinical studies in adults from developed countries have implicated Helicobacter pylori infections in the development of thrombocytopenia. However, studies in children, particularly those from low-income countries, are unusually scarce....

Clinical features of cats diagnosed with coccidioidomycosis in Arizona, 2004-2018.

The goal of this study was to describe the clinical presentation, diagnosis and treatment of coccidioidomycosis in cats residing in a region endemic for Coccidioides species. A retrospective review of records was performed at both primary and tertiary care veterinary practices in Tucson and Phoenix, Arizona, USA. Data collected included signalment, clinical signs, physical examination findings, diagnostic test results, treatment and outcome. Fifty-one feline cases were identified from six veterinary hospitals. Cats presented with clinical signs and laboratory abnormalities similar to what has been seen in dogs, including respiratory illness (n = 20/51), neutrophilia (n = 24/31), monocytosis (n = 17/31) and hyperglobulinemia (n = 16/30). However, cats at diagnosis were typically significantly ill, with 31/51 having disseminated infection, most commonly to the skin (n = 22). Additionally, 43/44 cats that had serum antibody tests performed were positive, and median titer at diagnosis was 1:32 (range 1:4 to ⩾1:256). Serum antibody titers were significantly reduced (P ⩽0.001) in cats that responded to treatment compared with cats that did not clinically improve. Forty of 46 cats that were treated with oral fluconazole responded and did not require additional therapy. Fourteen cats developed recurrent disease and all but one had antifungal therapy successfully reinstituted. Coccidioidomycosis is a disease of concern for cats residing in the regions endemic for Coccidioides species. Disease is most often disseminated at the time of diagnosis, possibly due to delays in presentation for care and recognition of the infection. Suspicion of disease, serum chemistries, blood cell counts, presence of antibody and imaging aid in the diagnosis of coccidioidomycosis in cats. Serum antibody reduction during treatment frequently correlated with an adequate response to medication. Consideration of coccidioidomycosis as a cause of illness will lead to earlier diagnosis and potentially better treatment outcomes in cats.

Serum anti-Helicobacter pylori antibody titer and its association with gastric nodularity, atrophy, and age: A cross-sectional study.

AIMTo clarify the role of serum anti-Helicobacter pylori (H. pylori) antibody titers in gastric cancer.METHODSIn this cross-sectional study, the effect of patients’ baseline characteristics and endoscopic findings on their serum antibody titers were assessed. We evaluated consecutive patients who underwent esophagogastroduodenoscopy and their first evaluation for H. pylori infection using a serum antibody test. We excluded patients with a history of eradication therapy. The participants were divided into four groups according to their E-plate serum antibody titer. Patients with serum antibody titers < 3, 3-9.9, 10-49.9, and ≥ 50 U/mL were classified into groups A, B, C, and D, respectively.RESULTSIn total, 874 participants were analyzed with 70%, 16%, 8.7%, and 5.1% of them in the groups A, B, C, and D, respectively. Patients in group C were older than patients in groups A and B. Gastric open-type atrophy, intestinal metaplasia, enlarged folds, diffuse redness, and duodenal ulcers were associated with a high titer. Regular arrangements of collecting venules, fundic gland polyps, superficial gastritis, and gastroesophageal reflux disease were related to a low titer. Multivariate analysis revealed that nodularity (P = 0.0094), atrophy (P = 0.0076), and age 40-59 years (vs age ≥ 60 years, P = 0.0090) were correlated with a high serum antibody titer in H. pylori-infected patients. Intestinal metaplasia and atrophy were related to age ≥ 60 years in group C and D.CONCLUSIONSerum antibody titer changes with age, reflects gastric mucosal inflammation, and is useful in predicting the risk of gastric cancer.

OR46 Donor-derived anti-HLA antibodies in a haploidentical hematopoietic cell transplant recipient shortly after transplant

A 15-year-old Caucasian male with high risk AML was referred to our institution for investigational therapy after relapsing from an 11/12 HLA-A mismatched (graft vs. host direction only) unrelated donor hematopoietic cell transplant (HCT). Prior to second HCT, the patient’s serum was negative for antibodies to class I and class II HLA by microarray single antigen bead assay. The patient received two progenitor cell infusions from his haploidentical mother; the first was depleted of TCRαβ+ cells and the second was depleted of CD45RA + cells. These procedures remove naive T cells, the major alloreactive component of donor T cells, while preserving TCRγδ+ and CD45RO+ memory T cells respectively, which may provide infection control and graft vs. leukemia effects. Eight days post-transplant and prior to neutrophil engraftment, the patient became refractory to platelets and was found to be highly sensitized to multiple HLA-A and B antigens, although none were donor-specific. Because the patient received rabbit anti-thymocyte globulin (rATG) during the preparative regimen, there was a concern that antibody reactivity could be due to residual rATG. However, dilutions of the rATG preparations from the same lots used in the patient revealed no specific activity in the single antigen bead assay. Serum from the patient’s mother/donor was tested and found to be positive for many of the same antibodies present in the patient, suggesting the patient’s antibodies originated in the donor. Antibody testing of patient serum at five and seven weeks post-transplant showed magnified and expanded sensitization, despite undetectable circulating B cells secondary to administration of rituximab in the preparative regimen for EBV prophylaxis. Escalating sensitization is unlikely to reflect passive transfer of antibody from donor to recipient. Plasma cells are long-lasting, antibody-secreting B cells that do not express CD20 and therefore would not be targets for destruction by rituximab. Taken together, the data indicate active transfer of rituximab-resistant antibody-producing passenger lymphocytes (likely plasma B cells) from a haploidentical donor to a transplant recipient at the time of progenitor cell infusion. B. Triplett: 7. Other (Identify); Company/Organization; Travel support (flight, hotel and registration) from Miltenyi to present previously published data at EBMT.

Pilot Study of Immunoblots with Recombinant Borrelia burgdorferi Antigens for Laboratory Diagnosis of Lyme Disease.

Accurate laboratory diagnosis of Lyme disease (Lyme borreliosis), caused by the spirochete Borrelia burgdorferi (BB), is difficult and yet important to prevent serious disease. The US Centers for Disease Control and Prevention (CDC) presently recommends a screening test for serum antibodies followed by confirmation with a more specific Western blot (WB) test to detect IgG and IgM antibodies against antigens in whole cell lysates of BB. Borrelia species related to BB cause tick-borne relapsing fever (TBRF). TBRF is increasingly recognized as a health problem in the US and occurs in areas where Lyme disease is prevalent. The two groups of Borrelia share related antigens. We have developed a modified WB procedure termed the Lyme immunoblots (IBs) using recombinant antigens from common strains and species of the BB sensu lato complex for serological diagnosis of Lyme disease. A reference collection of 178 sera from 26 patients with and 152 patients without Lyme disease were assessed by WB and IB in a blinded manner using either criteria for positive antibody reactions recommended by the CDC or criteria developed in-house. The sensitivity, specificity, positive and negative predictive values obtained with the reference sera suggest that the Lyme IB is superior to the Lyme WB for detection of specific antibodies in Lyme disease. The Lyme IB showed no significant reaction with rabbit antisera produced against two Borrelia species causing TBRF in the US, suggesting that the Lyme IB may be also useful for excluding TBRF.