Clinical characteristics, predictors of immune reconstitution inflammatory syndrome and long-term prognosis in patients with Kaposi sarcoma

OBJECTIVE To investigate the predictive factors for the development of Kaposi sarcoma-related immune reconstitution inflammatory syndrome (KS-IRIS) and long-term prognosis in patients starting combined antiretroviral therapy (cART). METHODS We studied a retrospective-cohort of consecutive antiretroviral-naïve patients with KS initiating cART from January 2005 to December 2011 and followed through June 2013. KS-IRIS was defined as ≥2 of the following: abrupt increase in number of KS lesions, appearance or exacerbation of lung-opacities or lymphedema, concomitantly with an increase in CD4+ cell-count ≥50 cells/mm3 and a decrease of >1 log in viral-load once started cART. We compared individuals who met KS-IRIS criteria with those that did not and described the long-term follow-up. RESULTS We included 89 patients, 88 males; 35 (39%) developed KS-IRIS at a median of 10 weeks (IQR 4-16). KS-IRIS patients had more pulmonary-involvement (60% vs. 16.6% of patients; p < 0.0001), eight died attributed to pulmonary-KS. Thrombocytopenia <100,000/mm3 at follow-up occurred in 36% of KS-IRIS vs. 4% in non-KS-IRIS patients (p = 0.0002), 45% KS-IRIS patients with thrombocytopenia died, non without KS-IRIS. Chemotherapy (bleomicyn-vincristine) was more frequently prescribed in KS-IRIS patients (88.6% vs. 29.6%) with no differences in outcome; 80% of all patients achieve KS complete remission, 52% of them never received chemotherapy. No difference between groups in the long-term follow-up (mean 52.4 ± 27.4 months) was found, only one patient developed a secondary malignancy (1.12%). CONCLUSIONS Lung-involvement was predictive of IRIS development. Thrombocytopenia in KS-IRIS patients at week 12 follow-up after cART initiation was associated with high mortality. Over a third of patients with KS achieve remission without chemotherapy. Individuals that survive the initial period of KS-IRIS adhere to cART had a good long-term prognosis.