Osteonecrosis of the femoral head in people living with HIV: anatomopathological description and p24 antigen test.

Objective: To examine the presence of HIV in bone tissue of people living with HIV (PLWHIV) with osteonecrosis of femoral head and describe clinical and anatomopathological findings.

Design: This is a case series which included 44 PLWHIV with osteonecrosis of femoral head who underwent total hip arthroplasty.

Methods: Clinical data were obtained through analysis of the patients' medical records. Bone tissue obtained during total hip arthroplasty was retrieved and sent for conventional and immunohistochemical analysis. Monoclonal antibodies were used to mark the p24 (HIV), CD31 (vascular endothelial cells), CD68 (macrophages), and D40 (cells of the lymphatic endothelium) antigens.

Results: Dyslipidemia was found in 48% of the patients and lipodystrophy in 31%. Histological analysis showed similar characteristics for the entire sample. Degeneration of joint cartilage was visualized with the presence of fissures and fibrillations, as well as subchondral sclerosis and necrosis of the subchondral cancellous bone tissue. Lymphoplasmocytic inflammatory reaction was observed, with the presence of macrophages containing a foamy, vacuolated cytoplasm, as well as the presence of ceroid pigment and occasional granulation tissue. The reaction with the monoclonal anti-p24 antibody was negative in the samples from all 44 PLWHIV undergoing hip arthroplasty. Reactions with the anti-CD31 and anti-D40 antibodies were negative. Staining with CD68 antibody confirmed that the cells visualized with foamy, vacuolated cytoplasm were macrophages.

Conclusion: p24 HIV antigen was not detected in the bone tissue of PLWHIV and osteonecrosis. The most frequent anatomopathological findings were extensive necrosis of bone tissue, large vacuoles filled with fat cells, inflammatory lymphoplasmocytic reaction with macrophages containing vacuolated cytoplasm, and the presence of ceroid pigment.