Background: Immune reconstitution inflammatory syndrome (IRIS) is a major concern
when starting highly active anti-retroviral therapy (HAART) in new patients and especially late presenters.
This study attempts to identify risk factors for IRIS and investigate whether certain treatment
regimens increase the probability of IRIS for patients at risk.
Methods: Retrospective single-centre study of HIV patients treated with HAART.
Results: A total of 417 patients were included. We identified 45 cases of IRIS in 37 patients; an incidence
of 13.3 cases over 1000 person-years. In univariate analysis, IRIS development was significantly
associated with CDC stage, the presence of an opportunistic infection (OI) at diagnosis, CD4
cell count and viral load at diagnosis and HAART initiation and the use of integrase strand inhibitors
(INSTIs). In multivariate analysis, INSTIs use (OR 2.89; 95%CI 1.26-6.64; p=0.012),
CD4≤200/mm3 (OR 5.56; 95%CI 2.2-13.98; p<0.001), and the presence of an OI (OR 4.74; 95%CI
2.13-10.23; p=0.012) were independent risk factors. Among INSTI regimens, dolutegravir (OR 4.99
vs. NNRTI; 95%CI 1.11-22.55; p=0.037) and elvitegravir (OR 4.82 vs. NNRTI; 95%CI 1.43-16.19;
p=0.011) seem to carry increased risk. Mortality was 18.9% (7/37) for IRIS patients compared to
9.7% (37/380) in the non-IRIS group. Mortality at any given time during follow-up was significantly
higher in the IRIS group (HR 3.2; 95%CI 1.39-7.36; p=0.006).
Conclusion: The use of INSTIs and especially DTG and EVG is associated with a higher probability
for the development of IRIS in the background of late presentation and the presence of OIs.
These data highlight the need for further research.