Biomedical subjects

S Leverenz

Publications and source records attributed to S Leverenz.

18 recordsLinked to original sources

PubMed1998

HLA class I and class II antibodies: monitoring before and after kidney transplantation and their clinical relevance.

BACKGROUND: In search of an alternative screening technique, we compared complement-dependent cytotoxicity (CDC) with PRA-STAT, a commercially available enzyme-linked immunosorbent assay (ELISA). METHODS: A total of 188 pre- and posttransplant sera from 50 renal allograft recipients were tested with both methods. RESULTS: A significant correlation was found between both methods. Discrepant results could be explained by the fact that PRA-STAT detects both HLA class I and II antibodies (while CDC with peripheral blood lymphocytes as target cell detects mainly HLA class I reactivity), by the presence of IgM antibodies (which are not detected by the IgG-specific ELISA test), and by CDC "false-positive" results due to antibody rejection treatment. The clinical relevance of antibodies detected by PRA-STAT is suggested by the following. (a) In eight patients, donor-specific HLA antibodies detected by PRA-STAT (but not seen by CDC) resulted in severe rejection episodes, which led to graft loss in four cases. In all but one patient, antibodies were directed against class II or mixtures of class I and H antigens. Six patients with complications were shown to have developed de novo antibodies against DQ incompatibilities. (b) Half of the patients with a positive ELISA test at the moment of crossmatch experienced complications. Such patients are at a threefold higher risk of suffering from rejection episodes and/or graft loss than patients who are not sensitized (P<0.05, Fisher exact test). CONCLUSIONS: Because PRA-STAT is very reproducible, detects both HLA class I and II antibodies, and is not influenced by rejection therapy, we consider it an additional tool for pre- and posttransplant monitoring of kidney allograft recipients.

Antibodies↗

PubMed1988

A common antidonor reactive serological pattern in patients with failed kidney regrafts.

Twenty retransplant patients were serially screened for donor-reactive antibodies (DRA). DRA appeared exclusively in patients whose grafts permanently failed and these DRA shared some common features, namely early appearance (days 4-8 post-transplant), high titers (1:10 up to more than 1:400), and broad anti-HLA specificity. This preliminary data would suggest that regrafted patients with primary graft failure represent a distinct subgroup of particularly immune responsive individuals.

Antibody Specificity↗

PubMed1986

Alloimmune neonatal neutropenia: clinical observations and therapeutic consequences.

Alloimmune neonatal neutropenia is a rare condition, it must be distinguished from hereditary forms of neutropenia and acquired neutropenia accompanying sepsis. In a family with four affected newborns, the degree of the disease became more and more severe from the first child to the third child. The third child died of sepsis. After birth of the third child, specific antibodies (anti-NA 1) reacting with the neutrophils originating from the father and the first two children were detected in the mother's serum. No neutrophils were detectable in the fourth child immediately after birth. In this child falling concentrations of diaplacentally transferred antibodies could be demonstrated over 8 weeks after birth. Neutrophil counts returned to normal as the antibodies disappeared. In this newborn, infection could be prevented by the use of a germ-free environment and antimicrobial prophylaxis. The antibody titres could only be lowered by repeated exchange transfusions with Na 1-free blood. White blood cell transfusion only resulted in a short transient effect on neutropenia.

Adult↗

PubMed1985

[Alloimmune neonatal neutropenia: clinical observations and therapeutic results].

Alloimmune neonatal neutropenia is a rare disease. A family with four affected newborns is described in which the course of the disease aggravated from the first to the third child. The third child died from generalized infection. In the mother's serum specific antibodies against neutrophils (anti-NA 1) were detected which reacted with cell suspensions from the father and the other children. In the fourth child no neutrophils were present even immediately after birth. In this child the diaplacental transferred antibodies were detectable in falling concentrations over 8 weeks. The number of neutrophils normalized when the antibodies disappeared. Infection in the newborn was prevented by care in an environment poor in bacteria and by antimicrobial prophylaxis. Repeated exchange transfusions with NA 1-free blood only lowered the antibody titer. Transfusions of white blood cell concentrates had only shortlived effects on the neutropenia.

Agranulocytosis↗

PubMed1974