A one-step Du test in microplates

A one-step Du test, developed for use in automated microplate systems, uses anti-D with 0.6 percent dextran to potentiate the reaction. Because the washing and reagent-adding steps of the antiglobulin test are not required, the Du test can be performed in the same microplate as the ABO/Rh test. A set of reactions prepared with this technique was visually interpreted and also classified by an automated microplate ABO/Rh system. Visual interpretation of reactions resulted in a sensitivity and specificity close to those of the antiglobulin test, although the sensitivity of the test was reagent-dependent. When the automated microplate blood grouping system was used, the test was not as sensitive or as specific as the antiglobulin test, although it may be sufficient for many applications.     

Donor-specific transfusions. Donor-recipient HLA compatibility, recipient HLA haplotype, and antibody production

HLA profiles of 25 donor-specific transfusion (DST) kidney donor-recipient pairs were analyzed for HLA antigen compatibility. Serum samples collected during and after DST were tested for cytotoxic antibodies against T and B lymphocytes of the donors and 30 normal individuals. Eleven recipients did not produce cytotoxic antibodies to the antigens of their DST donors, and eight produced cold and/or warm, broadly reactive B-cell antibodies. Six patients (24%) produced HLA-A, B, C, and/or DR antibodies. Three of these individuals produced antibodies after two immunizations, while others required three immunizations. Three of the 11 antibody nonproducers (17%) had not received previous transfusions, as compared to three of the eight antibody producers (43%). Comparison of HLA profiles revealed 22 percent of the HLA-A, B, DR identities between the transfusion donor and recipient in antibody nonproducers as compared to 9 percent of the HLA-A, B, DR identities in antibody producers. The HLA-A2, B40, DR4 haplotype and HLA-DRW6 antigen were more common among antibody producers than among nonproducers, who had an excess of the HLA-B8, DR3 haplotype. These results are consistent with the hypothesis that there may be high- and low-responder HLA haplotypes that control immunologic responsiveness to histocompatibility antigens.     

Antibodies against double-stranded DNA and development of polymyositis during treatment with interferon

Alpha interferons have become effective palliative treatments for patients with neuroendocrine tumours such as carcinoids and endocrine pancreatic tumours. However, several reports indicate an increased incidence of both autoantibodies and autoimmune diseases in patients treated with interferon-alpha (IFN-alpha). We studied the development of antibodies against double-stranded DNA (dsDNA) and clinical signs of autoimmune disease in 214 patients with malignant carcinoids or endocrine pancreatic tumours consecutively admitted for treatment with IFN-alpha. Seventeen patients (8%) developed antibodies against dsDNA, predominantly females (12 females and 5 males). One patient had clinical and laboratory signs of polymyositis. Among the other 16 patients, three developed hypothyroidism and in six patients the anti- dsDNA autoantibodies normalized despite continuing therapy. Although a significant number of patients developed autoantibodies against dsDNA, overt autoimmune disease related to these antibodies is a rare event and many patients spontaneously normalize these titres despite continuing IFN-alpha treatment.