Free light chains and the risk of AIDS-defining opportunistic infections in HIV-infected individuals

Abstract

Background. The relevance of B-cell dysfunction for progression to AIDS among human immunodeficiency virus (HIV)-infected individuals has not been clearly defined. We evaluated the association between circulating and free light chains (FLCs), which are markers of B-cell dysfunction, and risk of developing an AIDS-defining opportunistic infection in HIV-infected men. Methods. The study included 252 case patients with clinical AIDS and 252 HIV-infected controls from the Multicenter Hemophilia Cohort Study I. Case patients were matched to controls on birth date, specimen type, blood sample collection date, and CD4 cell count. Levels of and FLCs were measured in serum or plasma collected 0-2.5 years before selection. Elevated FLC levels ( or , above the upper limit of normal) were classified as polyclonal (normal-ratio) or monoclonal (abnormally skewed-ratio). We used conditional logistic regression to estimate odds ratios (ORs) for AIDS. Results. FLC levels were higher in case patients than in controls, for (median, 4.03 vs 2.98 mg/dL) and (3.77 vs 2.42 mg/dL) FLCs. Compared with normal levels, above-normal FLC levels were associated with AIDS (OR, 3.13 [95 confidence interval (CI), 1.78-5.49] for and 3.47 [2.31-5.20] for FLCs), and the association with AIDS was strengthened with increasing and FLC levels (P trends