Bronchoalveolar Lavage Fluid Cytomegalovirus DNA Load as a Predictor of Mortality in AIDS Patients with Pulmonary Infections: A Retrospective Cohort Study

Cytomegalovirus (CMV) pneumonia presents diagnostic challenges in AIDS patients, as plasma monitoring often fails to reflect pulmonary viral burden. This retrospective study evaluated the prognostic value of bronchoalveolar lavage fluid (BALF) CMV DNA loads in 189 AIDS patients with pulmonary infections and CD4⁺ T cell counts < 200 cells/μL. CMV DNA in BALF and plasma was quantified to analyze associations with immune status and 90-day all-cause mortality. CMV detection was significantly more frequent in BALF (49.7%) than plasma (26.6%), indicating viral compartmentalization. An optimal BALF cutoff of 10,000 copies/mL was established for mortality prediction. Patients exceeding this threshold exhibited significantly lower CD4⁺ counts, increased mechanical ventilation requirements (34.4% vs. 11.5%), and prolonged hospital stays. Crucially, a BALF CMV load > 10,000 copies/mL was identified as an independent predictor of 90-day mortality (adjusted odds ratio = 3.78; 95% CI: 1.12-12.71). In conclusion, pulmonary CMV replication is prevalent and often compartmentalized in AIDS patients. A BALF CMV DNA load exceeding 10,000 copies/mL serves as a biomarker of profound immunosuppression and independently predicts poor clinical outcomes, highlighting the necessity of quantitative BALF monitoring for risk stratification.