Pidotimod and Immunological Activation in Individuals Infected with HIV

The improvements in HIV infection therapy and the large availability of antiretroviral drugs have led to an increased survival among HIV infected people, and simultaneously to a raised morbidity and mortality due to not-AIDS-related events in this group compared to the general population. An increased systemic inflammation and a persistent immune activation play a pivotal role in determining high rates of non-AIDS comorbidities. In the last years, many natural or synthetic immunomodulatory molecules acting by different mechanisms have been conceived. Pidotimod is a synthetic dipeptide molecule showing immunomodulatory properties. The aim of this pilot study was to evaluate the effects of Pidotimod supplementation on residual inflammation in HIV infected population.

Forty HIV positive individuals under cART were enrolled: 30 were treated with Pidotimod supplementation (study group) and 10 served as control group (without Pidotimod supplementation). For all participants, Cystatin C, PCR, ESR, microalbuminuria, TNF-α, INF-γ, IL-4, IL-10, IL1β, IL-18 and IL-2 were measured at enrolment (T0), 4 weeks after of Pidotimod supplementation (T1), and 4 weeks after completing supplementation (T2).

In HIV positive participants treated with Pidotimod, the evaluation of cytokine levels showed that IL-10, IFN gamma, and IL-4 were significantly higher at enrolment compared to the control group. The increase under Pidotimod treatment persisted after supplementation suspension, while the pro-inflammatory cytokines levels were reduced. Salivary IgA also increased during 4 weeks of supplementation and persisted at 4 weeks after completing supplementation. On the other hand, the Cystatin C and microalbuminuria levels decreased over time, at a greater extent the Cystatin C serum levels.

The study findings showed that the HIV population receiving Pidotimod achieved a rebalancing of pro-inflammatory and anti-inflammatory cytokines as well as a significant reduction in cystatin C levels. The treatment further allowed for an increase in salivary IgA levels at all the analyzed times, as a secondary event to a remodulation of the immunological status obtained with pidotimod. This approach could represent a new way to design new intervention strategies aimed at improving the persistent immune activation status in the virologically suppressed HIV population.