Analysis of Cross-sectional and Longitudinal HLA and Anti-viral Responses After COVID Infection in Renal Allograft Recipients: Differences and Correlates.

Background: Characterization of anti-HLA versus anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) immune globulin isotypes in organ transplant recipients after coronavirus disease 2019 (COVID-19) infection has not been reported. We aimed to determine changes in anti-HLA antibodies in renal transplant patients with COVID-19 and compare the immunoglobulin and epitope-binding pattern versus anti-SARS-CoV-2 antibodies.

Methods: This is a cross-sectional study of 46 kidney transplant recipients including 21 with longitudinal sampling.

A Safe Anti-A2 Titer for a Successful A2 Incompatible Kidney Transplantation: A Single-center Experience and Review of the Literature.

Background: Kidney allocation system allows blood type B candidates accept kidneys from A2/A2B donors. There is no mandate by UNOS on which the anti-A2 level is acceptable. We aimed to investigate the safety of kidney transplant in blood group B patients with anti-A2 titers ≤16.

C1q-binding DSA and allograft outcomes in pediatric kidney transplant recipients.

Donor-specific antibody (DSA) is an independent risk factor for antibody-mediated rejection (ABMR) and graft loss. The C1q assay differentiates complement from non-complement-binding DSA and C1q-binding DSA may lead to poor allograft survival. Our aim was to characterize the type of DSA seen in pediatric kidney transplant recipients and to determine whether complement binding DSA was associated with inferior graft survival.

COVID-19 infection in kidney transplant recipients at the epicenter of pandemics.

We investigated the prevalence and clinical outcomes of COVID-19 in recipients of kidney transplants in the Bronx, New York, one of the epicenters of the pandemic. Between March 16 and June 2, 2020, 132 kidney transplant recipients tested positive by SARS-CoV-2 RT-PCR. From May 3 to July 29, 2020, 912 kidney transplant recipients were screened for SARS-CoV-2 IgG antibodies during routine clinic visits, of which 16.

Tacrolimus variability is associated with de novo donor-specific antibody development in pediatric renal transplant recipients.

Background: Donor-specific antibody (DSA) is a risk factor for antibody-mediated rejection and shortened graft survival. We investigated the role of intrapatient variability in tacrolimus trough levels on graft outcomes (i.e.

False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions.

Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center.

Increased access to transplantation of highly sensitized patients under the new kidney allocation system. A single center experience.

We aimed to investigate the impact of the new kidney allocation system (KAS) on the rate of transplantation of sensitized patients at our center. Pre-KAS and post-KAS intervals were Jan 1st to Dec 3rd 2014 and Jan 1st 2015 to Dec 3rd 2015, respectively. The number of deceased-donor crossmatches performed by flow cytometry increased from 715 pre-KAS to 1188 post-KAS.

Pregnancy in sensitized kidney transplant recipients: a single-center experience.

Background: We aimed to examine the clinical outcomes of sensitized pregnant kidney transplant recipients.

Methods: A retrospective cohort study of female patients who received kidney transplant at Montefiore transplant center between June 1, 2009 through December 31, 2014 and had a documented pregnancy in our system.

Results: We found that 11 women had pregnancies during this period with a median age of 36 yr (range 22, 39).

The prevalence and clinical significance of C1q-binding donor-specific anti-HLA antibodies early and late after kidney transplantation.

We aimed to determine the prevalence and clinical significance of complement-binding donor-specific antibodies (DSA) detected up to 30 years after kidney transplantation. Group 1 patients included 284 consecutive DSA negative patients who underwent kidney transplantation after 1 May 2009. Group 2 included 405 patients transplanted before this date and followed at our center with functioning allografts.

Clinical and molecular significance of microvascular inflammation in transplant kidney biopsies.

The diagnostic criteria for antibody-mediated rejection (AMR) are continuously evolving. Here we investigated the clinical and molecular significance of different Banff microvascular inflammation (MVI) scores in transplant kidney biopsies. A total of 356 patients with clinically indicated kidney transplant biopsies were classified into three groups based on MVI scores of 0, 1, 2, or more for Groups 1-3, respectively.

Pretransplant immunologic risk assessment of kidney transplant recipients with donor-specific anti-human leukocyte antigen antibodies.

Background: Patients with pretransplantation strong donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) are at higher risk for rejection. We aimed to study the safety of kidney transplantation in patients with lower strength DSAs in a prospective cohort study.

Methods: Three hundred and seventy-three consecutive adult kidney transplant recipients with (DSA+; n=66) and without (DSA-; n=307) DSA were evaluated.

Increased intragraft rejection-associated gene transcripts in patients with donor-specific antibodies and normal biopsies.

We investigated why some donor-specific antibody-positive patients do not develop antibody-mediated rejection. Of 71 donor-specific antibody-positive patients, 46 had diagnosis of antibody-mediated rejection and 25 had normal biopsies. Fifty donor-specific antibody-negative patients with normal biopsies were used as a control group.

Expression of immune inhibitory receptor ILT3 in acute myeloid leukemia with monocytic differentiation.

Background: The diagnosis of AML with monocytic differentiation is limited by the lack of highly sensitive and specific monocytic markers. Immunoglobulin-like transcript 3 (ILT3) is an immune inhibitory receptor expressed by myelomonocytic cells and at high levels by tolerogenic dendritic cells.

Methods: Using flow cytometry, we analyzed the expression of ILT3 in 37 patients with AML and 20 patients with no detectable disease.

Aberrant T-cell antigen expression in B lymphoblastic leukaemia.

B lymphoblastic leukaemia (B-ALL) cells are characterized by the expression of various B-cell antigens. Expression of T/Natural Killer-cell antigens, however, has rarely been reported in B-ALL (TAg+ B-ALL), and the significance of this aberrant antigen expression is unclear. We thus analysed the frequency of TAg+ B-ALL at our institution and investigated its significance in the context of immunophenotypes, cytogenetic/molecular findings, and prognosis.

Hematogones are markedly decreased in chronic myeloid leukemia: multiparametric flow cytometric analysis.

Past studies have shown decreased hematogones in the bone marrow of patients with myelodysplastic syndromes and acquired aplastic anemia. In this study, we examined the bone marrow of patients with chronic myeloid leukemia (n = 33, mean age 49 years, age range 2-83 years) for the presence of hematogones and compared their frequency with that of age-matched controls (n = 50). We found that the percentages of total and stage I hematogones were decreased in chronic myeloid leukemia at diagnosis (n = 25) and at follow-up post therapy (n = 8) when compared to age-matched controls (diagnosis, total: 0.

Pre- and posttransplantation allosensitization in heart allograft recipients: major impact of de novo alloantibody production on allograft survival.

The involvement of humoral response in allograft rejection has been suggested by both immunologic and histochemistry studies. In the present study, we explored the role of alloantibodies in a large cohort of heart allograft recipients followed for 15 years. Sequential samples of sera were obtained from 950 recipients of heart allografts before and after transplantation at the time when protocol endomyocardial biopsies were performed.

Increased adenosine triphosphate production by peripheral blood CD4+ cells in patients with hematologic malignancies treated with stem cell mobilization agents.

Hematopoietic stem cell (HSC) transplantation is an important therapeutic option for patients with hematologic malignancies. To explore the immunomodulatory effects of HSC mobilization agents, we studied the function and phenotype of CD4(+) T cells from 16 adult patients with hematologic malignancies undergoing HSC mobilization treatment for autologous transplantation. Immune cell function was determined using the Immuknow (Cylex) assay by measuring the amount of adenosine triphosphate (ATP) produced by CD4(+) cells from whole blood.

Membrane and soluble ILT3 are critical to the generation of T suppressor cells and induction of immunological tolerance.

The tolerogenic phenotype of human dendritic cells is characterized by high cell surface expression of the inhibitory receptor ILT3. ILT3 signals both intracellularly inhibiting tyrosine phosphorylation, NF-kappaB and MAPK p38 activity, transcription of certain co-stimulatory molecules, secretion of cytokines and chemokines, and extracellularly into the T cells with which the dendritic cells interact. Both ILT3(high) tolerogenic dendritic cells and soluble ILT3 induce CD4 Th anergy and differentiation of antigen specific CD8 T suppressor cells.

Hematogones: a review and update.

Our knowledge regarding the nature and function of 'hematogones' has evolved considerably, since the initial description more than 70 years ago. Once considered the 'mystery cells' of the bone marrow, major advances in immunology and flow cytometry have enabled us to better characterize these cells and recognize them as physiologic precursors of B-cells. In this review, we describe the morphologic and phenotypic characteristics and clinical relevance of hematogones, and report recent advances in our understanding and knowledge of these cells as they relate to physiologic and different pathologic conditions.

Hematogones are markedly reduced in pediatric acquired aplastic anemia: multiparametric flow cytometric analysis.

Acquired aplastic anemia (AA) and myelodysplastic syndromes (MDS) are bone marrow (BM) failure syndromes with overlapping clinical features, and at least a subset appears to share common pathophysiologic mechanisms. Recent studies of MDS have shown down-regulation of genes involved in B-cell development and decreased B-cell precursors (hematogones). We explored the possibility that AA, similar to MDS, might also be associated with defects in development of lymphoid cells, especially B-cells, by using flow cytometry to assess the presence of hematogones and mature lymphocytes in BM samples from 25 children with AA and 41 age-matched controls.

Significance of immune cell function monitoring in renal transplantation after Thymoglobulin induction therapy.

Monitoring of immune status in transplant recipients is essential for predicting the risk of rejection or infection. In this study, we assessed the significance of immune cell function in 76 renal allograft recipients after Thymoglobulin induction and initiation of maintenance immunosuppression. Using the Immuknow (Cylex Inc) assay, the amount of adenosine triphosphate (ATP) produced by CD4+ cells in response to phytohemagglutinin (PHA) was measured in patients whole blood.

Alloantibodies in heart transplantation.

The presence of complement fixing anti-human leukocyte antigen (HLA) antibodies in the circulation of organ transplant recipients may result in heart allograft rejection. Here, we assessed the clinical impact of pre- and post-transplantation allosensitization on long-term survival of heart allografts. Sequential samples of sera from heart allograft recipients were screened pretransplantation for panel reactive antibodies using the complement-dependent cytotoxicity test.

Suppression of xenogeneic graft-versus-host disease by treatment with immunoglobulin-like transcript 3-Fc.

Allogeneic hematopoietic cell transplantation represents an important therapy for certain malignant and nonmalignant diseases. However, graft-versus-host disease (GVHD) is a major cause of mortality and morbidity. The search for agents that can efficiently suppress GVHD has been going on for more than half a century.

Relevance of different antibody detection methods for the prediction of antibody-mediated rejection and deceased-donor kidney allograft survival.

Presensitizing alloantibodies may represent a grave danger in organ transplantation, increasing the risk of antibody-mediated rejection (AMR) and graft loss. However, not all antibodies are harmful to the graft. In our study of a cohort of 325 deceased-donor renal allograft recipients, the patients were determined eligible to receive an allograft based on a negative complement-dependent cytotoxicity (CDC) crossmatch (XM).