[Influence of HLA-A, B loci carrying Bw4 motif on HIV CD4 T cell count and viral load].

OBJECTIVE

To analyze the influence of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load of primary HIV infectors.

METHODS

The technique of SSP-PCR was employed to detect the HLA-A, B allele typing in 95 HIV infectors. And the roles of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load were analyzed.

RESULTS

(1) The population frequency of HLA-A, B loci carrying Bw4 motif was respectively 32.6% (31/95) and 60.0% (57/95). The population frequency of Bw4/4, Bw4/6, Bw6/6 located on HLA-B was 21.1% (20/95), 38.9% (37/95) and 40.0% (38/95) respectively. (2) Compared with those with CD4 T cell count less than 500/µl, more Bw4 motifs were expressed on HLA-A, B loci of patients with CD4 cell count more than 500/µl (mean rank, 56.7 vs 41.6, U = 749.5, P < 0.01). Moreover, the fewest infectors were those with HLA-A, B carrying 3 Bw4 motifs and CD4 T cell count fewer than 500/µl (1 case). And secondly were those with HLA-A, B carrying 0 or 3 Bw4 motif and CD4 cell count more than 500/µl (7 cases, χ(2) = 12.6, P < 0.01). (3) The infectors with HLA-A, B loci carrying 3 Bw4 motifs had more CD4 T cell count (median: 651/µl) and less viral load(lg median: 3.43)than those with HLA-A, B carrying 0 or 1 Bw4 motif (430 and 425/µl, 4.48 and 4.40). And the difference was significant (all P < 0.05). However, the CD4 cell count and viral load between the patients with HLA-A, B carrying 2 Bw4 motifs and 3 Bw4 motifs were insignificantly different (P > 0.05). (4) Irrespective of Bw4 motif on HLA-A locus, the infectors HLA-B carrying Bw4/4 homozygote had more CD4 cell count (median: 538/µl) and less viral load (lg median: 3.53) than those carrying Bw4/6 heterozygote or Bw6/6 homozygote (433/µl and 427/µl, 4.29 and 4.48, all P < 0.05). However, irrespective of Bw4 motif on HLA-B, the CD4 cell count and viral load were insignificantly different between the infectors HLA-A carrying Bw4 motif and non-Bw4 motif.

CONCLUSION

Bw4 motifs can increase the CD4 cell count and decrease the viral load of patients with primary HIV infection. Maybe Bw4/4 homozygote on HLA-B plays a role of delaying the disease progression.