Immunoglobulin isotypes and IgG subclasses as molecular markers of efficacy of Pentavalent antimonials treatment of American tegumentary leishmaniasis

MARCO JD; KORENAGA M; BARROSO PA; MORA MC; CAJAL SP; RUEDA P; JUÁREZ M; KROLEWIECKI A; ROMERO HD; KUMAZAWA H; DIOSQUE P; PADILLA AM; BASOMBRÍO MA; TARANTO N; HASHIGUCHI Y

Kochi, Japón

Otro; 63rd Annual Meeting of the Japanese Society of Parasitology - Western region; 2007

Japanese Society of Parasitology

The regime of the Pentavalent antimonial (Sbv) treatment for American cutaneous leishmaniasis is based on the clinical evolution of the lesion. However, this criterion is not always conclusive and difficult for suitable or adequate handling of the patients.  In this work, we tested the immunoglobulin (Ig) isotypes and IgG subclasses as putative markers of the therapeutic efficacy, since failure of treatment has often been reported. The levels of anti-Leishmania isotypes IgG, IgA, IgM and IgE, and the subclasses IgG1, IgG2, IgG3, and IgG4 were measured in sera of patients and control subjects by ELISA using a Leishmania amastigotes crude extract as antigen. Sera were collected before and at three different times after conventional Sbv therapy. According with the clinical evolution after completing the treatment, the patients were divided into two groups, the recovered (n = 9), with complete scarring of lesions and no recovered (n = 7), with absence or incomplete scarring of the ulcers. The no recovered group received further Sbv doses until cure. For each Ig, the OD post / OD pre-treatment ratio was calculated and the average per group compared. The ratios for the Ig isotypes decreased in both groups except for IgG, which increased in the no recovered group, and decreased in the recovered (p>0.05). Regarding to the IgG subclasses, IgG1 and IgG2 showed the same behavior as the most isotypes. In contrast, the IgG3 and IgG4 ratios were constant in the no recovered, 0.99 and 0.92, whereas in the recovered it decreased to 0.69 and 0.40 respectively (p < 0.05).  Since the variations of IgG3 and IgG4 levels reflected the failure or response to the Sbv treatment, they could be useful markers in the follow-up of the therapy.