A new duplication at the C4B locus associated with the HLA-Aw68, Cw8, Bw65 haplotype.

A family with a cross-over between HLA-B and HLA-DR was analysed for its complement alleles. This allowed location of the cross-over between HLA-B and C4. Furthermore, the same family showed a previously undescribed duplication at the C4B locus (C4B* 2,2) that was associated with the HLA-Aw68, Cw8, Bw65, C2*1, Bf*S, C4A*2, DR7, DQw2 haplotype.

HLA antigens and clinical manifestations in Crohn's disease.

A clinical, radiological and immunogenetical study was carried out on 51 Crohn's patients. Rheumatological disorders were found in 16 of them, with higher frequency in those with colon involvement only. A statistically significant increase in the frequencies of HLA-A9 and HLA-Cw3 was noted: Cw3 showed a particularly high frequency in males, and A9 in younger patients.

Fc-receptor function of the mononuclear phagocyte system in glomerulonephritis secondary to some multisystem diseases.

The Fc-receptor function of the mononuclear phagocyte system was examined in 30 patients affected by multisystem diseases with glomerular involvement by measuring the immune clearance of IgG-sensitized autologous red blood cells in vivo and the immune phagocytosis of monocytes in vitro. Patients studied in the phase of clinically active renal disease showed a significantly reduced Fc-receptor function by both in vivo (p less than 0.001) and in vitro (p = 0.

Identification of anti-DQ alloantisera correlated with DR5.

Using classical serological methods, we have been able to distinguish anti-HLA-DR from anti-DQ antibodies. The specificity of alloantisera for DQ could be identified on the basis of differential reactivity against B cell and monocyte-enriched leucocyte suspensions and lack of inhibition of cytotoxicity by anti-DR monoclonal antibodies. Some alloantisera, whose reactivity was significantly correlated with DR5, were found to exhibit these characteristics.