IL4 and pulmonary fibrosis: In evaluating the production of IL-4, which is a cytokine already characterized in Th2 immune response present in helminthic infections [24,28] and pulmonary fibrosis [1,6,36], we observed a significant increase in IL-4 in the A. suum infection and comorbidity groups when related to the control groups and only submitted to fibrosis induction (Fig 4A).