Intracranial hemorrhage in utero due to isoimmune neonatal thrombocytopenia.

A case is presented of isoimmune neonatal thrombocytopenia complicated by spontaneous intracranial hemorrhage in utero. Maternal platelets were found to be negative for the PLA1, Baka, and HLA-A2 antigens. The present case demonstrates that the classical conservative approach of elective cesarean section can not guarantee against this crippling event.

Anti-Km in a transfused man with McLeod syndrome.

An 18 year old man has red cells of the McLeod phenotype in the Kell system but does not have chronic granulomatous disease. His red cells show acanthocytic morphology and there is evidence of a compensated hemolytic state. Following an accident he was transfused with blood of common Kell type and made anti-K and anti-Km. Leukocytes from the patient are deficient in Kx antigen but the cells appear to have normal function. The mother is a carrier of the variant Xk allele and has a double red-cell populatio of McLeod cells and cells of common Kell type. The family may be informative with respect to linkage between the Xk and Xg loci. One of the mother's 5 brothers and one of her maternal uncles are possible Xk:Xg recombinants.

Formaldehyde-related antibodies in hemodialysis patients.

In a study of anti-N-like antibodies, we tested sera from 93 hemodialysis patients for hemagglutination reactions with untreated and formaldehyde-treated reagent red blood cells. Six of 22 sera from patients who had been dialyzed with formaldehyde-sterilized membranes had anti-N-like activity and 20 (91%) specifically agglutinated formaldehyde-treated red blood cells. Sera from 71 patients dialyzed with disposable membranes neither had anti-N-like activity nor agglutinated formaldehyde-treated red blood cells. The agglutination of formaldehyde-treated red blood cells by sera from hemodialysis patients was unrelated to MNU phenotypes and, therefore, identified a second serologic specificity, provisionally termed "anti-formaldehyde." "Anti-formaldehyde" was absorbed by and eluted from NN red blood cells as well as from formaldehyde-treated red blood cells regardless of MNU phenotype. All eluates and sera containing anti-N-like activity also agglutinated formaldehyde-treated red blood cells, typically after the addition of anti-human serum. These findings are consistent with the hypothesis that anti-N-like reactions of hemodialysis patients' sera represent cross reactions of formaldehyde related antibodies with N antigens of normal red blood cells.

Another Kell-related antibody, anti-K19.

A new high-frequency antigen related to the Kell system was defined by the serum of a patient, Mrs. Sub. The antigen was lacking from her cells and those of one of her three siblings. All random cells tested were incompatible with her serum as were bloods of other various "null" phenotypes, but Ko bloods were compatible suggesting that the antibody, subsequently called anti-K19, was related to the Kell blood group system.

Rh sytem. Genetics and function.

Little is known about the exact genetic control of the Rh system. The Rh antigen is a large protein molecule carrying many antigenic determinants. The structural genes controlling its production comprise a gene complex that has probably evolved by unequal crossover and mutation at the duplicated points. No convincing evidence for crossing-over within the gene complex has been found since the discovery of Rh. Studies of Rhnull families provide evidence for unlinked control genes that influence the ability of the structural Rh genes to function. It was hoped that the Rhnull bloods would provide information to establish the function of the Rh antigen, because the antigen appears to be necessary to maintain the integrity of the red cell membrane. However, the abnormalities of the Rhnull cells (increased Na+K+ pumps) have not been tied directly to their lack of Rh antigens.

Anti-Lu14: a Lutheran antibody defining the product of an allele at the Lu8 blood group locus.

A 'new' Lutheran-related antibody, named anti-Lu14, reacts with approximately 2.4% of random bloods. Red cells of the rare Lu:-8 phenotype are Lu:14. The data indicate, with a high probability, that the Lu 14 antigen is a product of an allele of Lu8 and that Lu14 and Lu8 comprise a third pair of alleles at the Lutheran locus. Red cells of the original Sw (a+) propositus are Lu:14. By coincidence, he has inherited two low-incidence genes. This observation may explain the discrepancy in different families concerning a possible relationship between Swa and Lutheran. Pedigree information now suggests that Swa is not a Lutheran gene.

Confirmation of K11 and K17 as alleles in the Kell blood group system.

Tests of three new unrelated K:-11 people and their relatives confirm that K11 is allelic to K17 (Wka) and belongs to the Kell system.