Table 1

Survival analysis of the effect of homozygosity at the three HLA class I loci -A, -B, and -C on susceptibility to progression to three AIDS endpoints (AIDS-1993, AIDS-1987, and death) for seroconverters of MACS, MHCS, SFCC, and ALIVE (20–22). HLA class I typing is described in (40). Homozygosity at one locus only and homozygosity at two or three loci were considered as covariables in a Cox model analysis (only five individuals were homozygous at HLA-A, -B, and -C loci, precluding a robust statistical treatment of triple homozygotes). Relative hazards (RH) and theirP values are given for AIDS-1993, AIDS-1987, and death. There were not a sufficient number of African Americans homozygous for two or three HLA class I loci to provide a robust analysis. Homozygosity at each of the loci (HLA-A, -B, and -C) was considered as a Cox model explanatory variable. Each analysis was performed on seroconverters in combined cohorts, separately for Caucasians and African Americans, and for all ethnicities. Analyses were performed without considering specific allele protection and also as adjusted for the AIDS accelerating effects of B*35 and Cw*04(41). RH values were similar, and adjusted values are presented here. A survival analysis was also performed after adjusting the RH values for the protective effects of CCR5-Δ32,CCR2-64I, and SDF1-3'A (22). The results (27) revealed no epistatic interaction of these loci with HLA homozygosity because the adjusted RH andP values were largely consistent with those reported here. Dashes indicate no data available.

AIDS outcomeN/eventsHomozygous for locus
HLA-AHLA-BHLA-C
RHPRHPRHP
All ethnicities
AIDS-1993 497/3381.684 x 10−4 2.911 x 10−4 1.62 0.005 2.814 x 10−5 1.923 x 10−4
AIDS-1987498/257 1.78 5 x 10−4 4.071 x 10−6 1.69 0.006 3.835 x 10−7 2.23 5 x 10−5
Death 498/200 1.47 0.05 3.842 x 10−5 1.58 0.04 3.092 x 10−4 1.96 0.002
Caucasians
AIDS-1993 329/252 1.560.01 3.38 2 x 10−5 1.52 0.033.32 1 x 10−5 2.074 x 10−4
AIDS-1987 330/208 1.55 0.024.80 1 x 10−7 1.71 0.009 4.487 x 10−8 2.06 0.001
Death 330/1671.39 0.13 4.33 4 x 10−6 1.560.06 3.54 4 x 10−5 2.00 0.004
African Americans
AIDS-1993 144/672.37 0.007 2.98 0.01 2.57 0.201.80 0.15
AIDS-1987 144/36 4.402 x 10−4 2.68 0.13 1.32 0.793.64 0.005
Death 145/25 2.70 0.062.620.20 0.00 0.99 2.31 0.19
RHPRHP
Homozygous at one HLA-I locus Homozygous at two or threeHLA-I loci