An unusual concurrence of graft versus host disease caused by engraftment of maternal lymphocytes with DiGeorge anomaly.

We describe a girl with DiGeorge anomaly and normal cytogenetic and molecular studies, whose clinical course was complicated by graft versus host disease caused by intrauterine materno-fetal transfusion, and several immunohematological alterations including a monoclonal gammapathy of undetermined significance (first IgG, which subsequently changed to IgM). The main clinical features and pathological findings are discussed.

HLA class II immunogenetics and incidence of insulin-dependent diabetes mellitus in the population of Cantabria (Northern Spain).

HLA class II genes were analyzed to study IDDM susceptibility in Cantabria (Northern Spain). Patients showed highly significant increases in DRB1*0301 (RR = 4.581, p < 0.

Reactive oxygen intermediates during programmed cell death induced in the thymus of the Ts(1716)65Dn mouse, a murine model for human Down's syndrome.

Down's syndrome (DS) is one of the most frequent genetic disorders in humans. It has been suggested that overexpression of copper-zinc superoxide dismutase (SOD-1) in DS may be involved in some of the abnormalities observed, mainly neurodegenerative and immunopathological processes. One of the consequences is early thymic involution.

HLA-DR, DQ nucleotide sequence polymorphisms in the Pasiegos (Pas valleys, Northern Spain) and comparison of the allelic and haplotypic frequencies with those of other European populations.

In general, Northern Spain has remained geographically isolated from neighboring Spanish regions for centuries: steep mountains create small isolated and inbred population groups with their own characteristic cultures and unique gene pools. The Pasiego region forms an area of distinctive characteristics among the people living in Northern Spain, although the origin of the inhabitants of the Pas valleys (Pasiegos) is not clearly defined. We have studied the MHC class II alleles in a large sample of unrelated individuals living in the Pas valleys.

Oxidation of defined antigens allows protein unfolding and increases both proteolytic processing and exposes peptide epitopes which are recognized by specific T cells.

The participation of oxidative mechanisms in major histocompatibility complex (MHC) class II-restricted antigen presentation was studied in vitro. In general, antigen processing is inhibited when peritoneal macrophages (MO) are incubated with scavengers of reactive oxygen intermediates (ROI): mannitol (an.OH scavenger), dimethylurea (DMTU, which reacts with H2O2 and HOCl) and NCO-700 (an epoxysuccinic acid derivative which inhibits oxidant production by activated phagocytes and can scavenge reactive oxygen species in both NaOCl and hypoxanthine (XOD) systems).