Identification of immunoreactive proteins of Dirofilaria immitis and D. repens recognized by sera from patients with pulmonary and subcutaneous dirofilariosis.

Human pulmonary and subcutaneous dirofilariosis caused by Dirofilaria immitis and Dirofilaria repens are worldwide diagnosed with increasing frequency. These species are responsible for the development of benign pulmonary and subcutaneous nodules, respectively, that can be confused with lung or cutaneous cancer. The aim of the present work was to identify D. immitis and D. repens proteins differentially recognized by serum samples from individuals with human pulmonary and subcutaneous dirofilariosis, using two-dimensional electrophoresis and mass spectrometry. Twenty-three immunoreactive proteins of D. immitis and 15 of D. repens were identified. The results point to the existence of differential antigenic recognition in each species, both in the number and type of proteins recognized. Individuals with pulmonary dirofilariosis recognized, on the proteome of D. immitis, among others, different isoforms of 6 enzymes involved in glycolysis, 3 redox-related proteins with antioxidant capacity and 3 heat shock proteins. Individuals with subcutaneous dirofilariosis recognized on the proteome of D. repens only 3 glycolytic enzymes, one protein involved in redox processes and one heat shock protein. These data suggest that in cases of pulmonary dirofilariosis there exists a wider recognition of immunoreactive D. immitis proteins related to key survival processes, such as energy generation, the struggle against oxidative stress and molecular repair, than in cases of human subcutaneous dirofilariosis against D. repens. This could contribute to explain the differences described in the capacity of D. immitis and D. repens development and in the frequency of occurrence of pulmonary and subcutaneous dirofilariosis in the human host.