Abstract: OBJECTIVE To observe the correlation between the opportunistic infections in acquired immune deficiency syndrome (AIDS) patients complicated with pneumocystis pneumonia (PCP) and the CD₄⁺ T cell counts.METHODS A total of 147 AIDS patients who were hospitalized in Hangzhou Xixi Hospital from 2012 to 2016 were enrolled in the study, including 60 AIDS patients complicated with PCP and 87 AIDS patients without PCP.The CD₄⁺ T cell counts, CD₈⁺ T cell counts, and ratio of CD₄⁺ T cell to CD₈⁺ T cell were observed and compared between the opportunistic infection group and the non-opportunistic infection group; the prevalence of opportunistic infections in the patients with different levels of CD₄⁺ T cell was further analyzed.RESULTS Of the 60 patients, 47 had the opportunistic infections, with the infection rate 78.33%; the oral candidiasis, cytomegalovirus infection,bacterial pneumonia,syphilis,and hepatitis B were dominant among the opportunistic infections, accounting for 41.67%, 31.67%, 31.67%, 30.00%, and 11.67%, respectively.The CD₄⁺ T cell counts of the AIDS patients complicated with PCP were less than 200×10⁶/L, most of whom were no more than 50×10⁶/L.The CD₄⁺ T cell counts and ratio of CD₄⁺ T cell to CD₈⁺ T cell were remarkably lower in the opportunistic infection group than in the non-opportunistic infection group (P＜0.01,P＜0.05).The incidence of opportunistic infection of the patients with the CD₄⁺ T cell counts no more than 50×10⁶/L was 90.91%, significantly higher than 57.14% of the patients with the CD₄⁺ T cell counts ranged between 51 and 100×10⁶/L and 33.33% of the patients with the CD₄⁺ T cell counts ranged between 101 and 200×10⁶/L(P＜0.017).CONCLUSIONThe incidence of opportunistic infections is high in the AIDS patients complicated with PCP, there are a great diversity of pathogens causing the infections in the AIDS patients complicated with PCP, and the CD₄⁺ T cell count is closely associated with the opportunistic infection in the AIDS patients complicated with PCP.The risk of complication with multiple opportunistic infections may be further increased with the decline of the CD₄⁺ T cell level and immunity.