Significant differences in GM allotype frequencies between two sympatric tribes with markedly differential susceptibility to malaria.

Fulani and Masaleit, sympatric tribes in eastern Sudan, are characterized by marked differences in susceptibility to Plasmodium falciparum malaria. To determine whether the two tribes differ in the frequency of immunoglobulin GM/KM allotypes, which are associated with immunity to several pathogens, serum samples from 50 Fulani and 50 age- and sex-matched Masaleit subjects were allotyped for several GM/KM determinants. The distribution of GM phenotypes as a whole, as well as a particular combination of KM and GM phenotypes, differed significantly between the two tribes (P = 0.03). These data suggest that GM allotypes may contribute to the genetic aetiology of malaria.

Antibodies to human cytomegalovirus protein UL83 in systemic sclerosis.

OBJECTIVE: To determine whether elevated levels of antibodies to HCMV protein UL83 were present in patients with SSc and if their prevalence was associated with major SSc-associated autoantibodies. METHODS: The study population consisted of 253 Caucasian subjects (110 SSc patients and 143 controls). IgG antibodies to UL83 were measured by an enzyme-linked immunosorbent assay (ELISA). Antibodies to centromere and RNA polymerase (RNAP) were determined by indirect immunofluorescence and immnoprecipitation methods, respectively. RESULTS: The mean level of anti-UL83 antibodies in the sera of SSc patients as a whole was significantly higher than that in control subjects (14.75 vs 10.6 units/microl, p = 0.002). Both subgroups of patients contributed to this variation: compared to controls, anti-UL83 antibody levels were higher in diffuse (16.32 vs 10.6 units/microl, p = 0.012) as well as in those with the limited form of the disease (13.95 vs 10.6 units/microl, p = 0.015). Anti-UL83 antibodies were not associated with major SSc associated autoantibodies. CONCLUSION: Humoral immunity to HCMV protein UL83 may be relevant to the etiopathogenesis of scleroderma.

Interleukin-10 genotypes are associated with systemic sclerosis and influence disease-associated autoimmune responses.

Systemic sclerosis (SSc; scleroderma) is a connective tissue disease, characterized by fibrotic, immunological, and vascular abnormalities. Interleukin-10 (IL-10) is an anti-inflammatory cytokine that modulates collagen production and B-cell survival. To determine if certain IL-10 genotypes are risk factors for the development of SSc and influence disease-associated autoimmune responses, 248 Caucasian and 264 Japanese SSc patients and controls were genotyped for three loci: -3575, -2849, and -2763. Sera from patients were characterized for SSc-associated autoantibodies. In Caucasians, at -3575 and -2763, the frequency of AA homozygotes was higher in patients as compared with controls (P=0.0005; P=0.002). In Japanese subjects, the frequency of AC heterozygotes at -2763 was higher, and that of CC homozygotes lower, in patients with diffuse SSc as compared to controls (P=0.04). Particular IL-10 genotypes were associated with SSc-related autoantibodies. These results suggest that IL-10 genotypes contribute to the etiology of scleroderma.