Immunomodulating dose of levamisole stimulates innate immune response and prevents intestinal damage in porcine rotavirus diarrhea: a restricted-randomized, single-blinded, and placebo-controlled clinical trial.

A restricted-randomized, single-blinded, placebo-controlled clinical trial was conducted to examine whether immunomodulating dose of levamisole (LMS) can stimulate certain antiviral immune markers by measuring the concentrations of interferon-γ (IFN-γ), nitric oxide (NOx), and total immunoglobulin G (IgG); prevents the gut injury; and reduces fecal consistency and dehydration scores in rotavirus type A (RVA)-positive piglet diarrhea. The trial was executed between November 2015 and May 2016 in an institute owned experimental swine production farm. The naturally RVA-exposed diarrheic piglets were used in the study. The piglets born between November 2015 and May 2016, age group of 0 to 2 weeks and confirmed for RVA-positive diarrhea, were randomized to receive supportive treatment (ST) or ST along with levamisole (LMS + ST) at immunomodulating dose. Simultaneously, six piglets were randomly selected from healthy population and kept as placebo control. The primary outcome was reduction of fecal consistency and dehydration scores (≤ 1) over the trial period. The secondary outcome was reduction of concentration of gut injury marker and stimulation of immunomodulatory function. The LMS + ST treatment progressively improved the total leukocyte, neutrophil count, IgG concentration (p < 0.05), and reduced the intestinal fatty acid-binding protein 2 (IFABP-2) concentration in RV-positive diarrheic piglets than ST only. Although NOx and IFN-γ concentrations were enhanced initially on day 3, however, the values reduced significantly on day 5 in response to LMS + ST compared to ST. Interestingly, the scores of fecal consistency and dehydration of RVA-positive diarrheic piglets were dropped much earlier (on day 3) in response to LMS + ST than ST alone. The results indicate that LMS along with supportive treatment non-specifically modulated innate immunity and restored intestinal gut health, and thus, LMS may represent an additional therapeutic agent for management of RVA-inflicted piglet diarrhea.