Auto anti-M antibody following renal transplantation

Neuronal-derived extracellular vesicles are enriched in the brain and serum of HIV-1 transgenic rats

Despite the efficacy of combination antiretroviral therapy (ART) in controlling human immunodeficiency virus (HIV-1) replication, cytotoxic viral proteins such as HIV-1 transactivator of transcription (Tat) persist in tissues such as the brain. Although HIV-1 does not infect neuronal cells, it is susceptible to viral Tat protein-mediated toxicity, leading to neuroinflammation that underlies HIV-associated neurocognitive disorders (HAND). Given the role of extracellular vesicles (EVs) in both cellular homoeostasis and under pathological conditions, we sought to investigate the alterations in the quantity of neuronal-derived EVs in the brain - as defined by the presence of cell adhesion molecule L1 (L1CAM) and to evaluate the presence of L1CAM⁺ EVs in the peripheral circulation of HIV-1 transgenic (HIV-1 Tg) rats. The primary goal of this study was to investigate the effect of long-term exposure of HIV-1 viral proteins on the release of neuronal EVs in the brain and their transfer in the systemic compartment. Brain and serum EVs were isolated from both wild type and HIV-1 Tg rats using differential ultracentrifugation with further purification using the Optiprep gradient method. The subpopulation of neuronal EVs was further enriched using immunoprecipitation. The current findings demonstrated increased presence of L1CAM⁺ neuronal-derived EVs both in the brain and serum of HIV-1 Tg rats.

A human monoclonal IgM kappa cold agglutinin recognizing oligosaccharides with immunodominant sialyl groups preferentially at the blood group M-specific peptide backbone of glycophorins: anti-PrM

A kappa-monotypic IgM high titer cold agglutinin reacting like anti-Pr at low, like anti-M at higher temperatures, is described. It recognizes tetra- and/or trisaccharides with immunodominant sialyl groups on glycophorins A, B, C like anti-Pr. Its affinity to the oligosaccharides is, however, approximately 10-fold increased when they are attached to the M-specific peptide backbone of glycophorin A. The antibody, termed anti-PrM, occurred in a blood group MN patient with chronic cold agglutinin disease and caused autoimmune hemolytic anemia.

Anti-erythrocyte antibodies, leukocytotoxins and human renal allograft survival

ABO blood group compatibility is generally required for successful human kidney transplants and new data suggest donor-recipient incompatibility for the Lewis or multiple minor blood groups is detrimental. This is of special importance in the setting of liberal transfusions prior to transplant. To assess the impact of immunizing exposure to disparate blood groups of ABO-matched transfusions and kidney transplants, we studied the interrelationships of anti-erythrocyte antibodies, leukocytotoxins and graft survival in 42 kidney transplant recipients. Three hundred forty-four sera were screened for anti-erythrocyte antibodies using standard hemagglutination techniques and leukocytotoxins, using the antiglobulin method. Statistical analysis by computer used a 2 x 2 x 2 contingency table with model fitting. Only 13 of 42 patients had anti-erythrocyte antibodies at some time: anti-I (4); anti-Kell (1); cold panagglutinin (7); unidentifiable agglutinin (1). Of 42 patients, 16 had no detectable leukocytotoxins. By computer analysis, immunizations to blood group and HLA antigens were independent phenomena. Analysis showed that leukocytotoxins, but not anti-erythrocyte antibodies, were associated with poor graft survival. A computer generated probability of graft survival by antibody status is presented. We conclude that immunization to blood group antigens is not common, is largely non-specific, and is not detrimental to kidney graft survival.