Background: A high incidence of nontraumatic osteonecrosis has been reported in HIV-infected patients. We investigated the levels of D-dimer and C-reactive protein (CRP) in a cohort of HIV-infected adults with and without osteonecrosis of the femoral head.
Methods: Forty-three HIV-infected patients with osteonecrosis of the femoral head and a comparison group of 50 HIV-infected patients with negative MRI of the hips and for whom serial plasma samples were available were included. D-dimer and CRP levels were measured prior to and at the time of diagnosis for osteonecrosis patients, at the time of negative MRI of the hips for controls, and at least 6 months later for both groups.
Results: Biomarker levels were elevated at the time of diagnosis in the osteonecrosis cohort compared with controls. Median D-dimer value was 0.32 μg/ml in the osteonecrosis group compared with less than 0.22 μg/ml in the control group (P = 0.016). For CRP, the corresponding values were 2.52 mg/l and 1.23 mg/l (P = 0.003). Postdiagnosis, D-dimer and CRP levels were also elevated in the osteonecrosis patients compared with controls. Linear regression demonstrated a rise in D-dimer levels from prediagnosis to diagnosis in the osteonecrosis patients whereas CRP levels did not change significantly over time.
Conclusion: Compared to controls, patients who developed osteonecrosis had elevated levels of D-dimer and CRP at diagnosis. D-dimer levels increased whereas CRP levels did not change significantly from prediagnosis to diagnosis. These data suggest that patients with higher levels of inflammation are at an increased risk of osteonecrosis.