The Role of Serum Markers in the Diagnosis of Pulmonary Infections in Acquired Immune Deficiency Syndrome (AIDS) Patients

Abstract

Background. The etiology and frequency of pulmonary infections in HIV patients varies according to the geographic regions and the availability of ART. Methods. Cross-sectional study from 2012 to 2016 that included HIV-patients hospitalized due to pulmonary infections. The diagnosis of Pneumocystis jirovecii pneumonia (PJP) was according to WHO clinical criteria. Community-acquired pneumonia (CAP) and lower respiratory infection (LRTI) was based on clinical symptoms and imaging exams. The etiologies were determined by microbiological and serological exams. Clinical and epidemiologic data were collected from the patients' records. Serums from patients were tested for (1-3)-β-D-glugan (BG): cut-off >80 pg/mL, and lactate dehydrogenase (LDH). Respiratory secretions were tested for P. jirovecii by loopmediate isothermal amplification (LAMP). The association among the variables was analyzed by univariate and multivariate regression analysis. Results. Sixty patients were included. Patients were classified in three groups according to diagnosis: PJP, 19 patients; CAP, 18 patients and other infections (23 patients: tuberculosis: 5; LRTI: 9; histoplasmosis: 2; nocardiosis: 1; cryptococosis: 1; disseminated strongyloidiasis: 1; pulmonary embolism: 1; and undiagnosed: 3). Nine patients died and 4 due to PJP. The duration of the diagnosis of HIV infection was shorter in the PJP group (4.94 years) versus CAP (14 years) and other diagnosis (10 years) (p = 0.003). Mean count of T CD4+ cells was significantly lower in patients with PJP (40 cells versus 230 cells in CAP and 97cells in others; p = 0.001). The multivariate analysis showed that higher values of BG (mean: 241 pg/mL for PJP versus 29: CAP and 52: others) and LDH (mean: 761 U/L for PJP; 419 CAP and 441 others) were associated with PJP. PJP was the AIDS-defining illness in 11 of the 16 patients diagnosed as AIDS at the hospitalization. LAMP identified P. jirovecci DNA in 5 of 16 patients diagnosed as PJP Conclusion. After decades of AIDS epidemic, we observed a high prevalence of PJP over other pulmonary infections. BG and LDH may be suitable markers for the diagnosis of PJP in our HIV population. There is a need for precocious diagnosis of HIV-infected patients in our setting where we have a well established National HIV/ AIDS program with free access to ART.