HIV-infected patients with Pneumocystis-pneumonia (PCP) may develop paradoxical immune reconstitution inflammatory syndrome (IRIS), when combination antiretroviral therapy (cART) is started early during the course of PCP-treatment (PCPT). The aim of this study was to identify risk factors and predictors for PCP-IRIS and to improve individualized patient care.

: An ICD-10 code hospital database query identified all Frankfurt HIV Cohort patients being diagnosed with PCP from January 2010 – June 2016. Patient charts were evaluated retrospectively for demographic, clinical and therapeutic (cART/PCPT) characteristics and incidence of paradoxical IRIS according to French's case definitions.

: IRIS occurred in 12/97 patients that started cART while on PCPT (12.4%). They had a higher rate of re-hospitalization (41.7% vs. 4.7%; odds ratio (OR) 14.46; p=0.009), intensive care treatment (66.7% vs. 30.6%; OR=4.54; p=0.018), and longer median hospitalization (48 days vs. 23; p<0.001). A high HIV-RNA level (>6Log10/ml) before cART initiation was associated with IRIS development (41.6% vs. 15.0%; OR 4.05; p=0.042). Serum immunoglobulin G-levels (IgG) [mg/dl] were lower (894.0 vs. 1446.5; p=0.023).

: Higher hospitalization rate and morbidity parameters underscore the clinical importance of PCP-related paradoxical IRIS. A baseline viral load of >6Log10/ml and serum IgG may help to assess individual risks for PCP-IRIS.