Increased microvascular network in bone marrow of HIV-positive haemophilic patients

Objectives Angiogenesis has been associated with the pathogenesis of myelodysplastic syndromes (MDSs). However, less is known about the significance of this process in the bone marrow of HIV-positive patients with myelodysplastic features (MDF). Methods Trephines from 22 HIV-positive haemophilic patients were immunostained for CD34 antigen, and the microvessel density (MVD) was quantitatively evaluated and compared with that of 21 biopsies from patients with primary MDS and with that of 12 control bone marrows with no evidence of marrow disease. Results Bone marrow MVD in HIV-positive haemophilic patients was similar to that in patients with MDS; however, both groups revealed significantly higher MVD counts than those of control bone marrows (P = 0.002). Mean MVD counts of HIV-positive haemophilic patients were significantly associated with HIV RNA levels (P = 0.008). In contrast, no correlation was found between MVD and clinical HIV stage or CD4 counts at the time of biopsy. Conclusions These results suggest a direct involvement of HIV in the pathogenesis of MDF in HIV infection. Elucidation of the mechanisms underlying bone marrow angiogenesis in HIV-positive patients may provide further insights into the pathobiology of AIDS.