Variation of peripheral lymphocyte subsets in leishmaniotic dogs treated with different drugs

Background: lymphocytes play a crucial role in directing the immunological response to leishmania infection. Methods: 25 symptomatic dogs were enrolled and allocated to different therapeutic groups on the basis of owner’s compliance: meglumine antimoniate (MA), spiramycin-metronidazole (SM), marbofloxacin (MX); allopurinol administration was always associated. Dogs were checked monthly from T0 to T180 and classified as symptomatic (S), partial remission (PR) or complete remission (CR). Flow cytometric percentage of circulating CD4+ and CD8+ lymphocytes and CD4/CD8 ratio were determined. Results: CD4+ and CD4/CD8 showed a positive correlation with time; the opposite occurred for CD8+. At T0 CD4+ and CD4/CD8 were above reference range, while CD8+ was below; all parameters entered the reference range at T90. Positive and negative correlation with clinical improvement (S, PR, CR) was present for CD4/CD8 and CD8+, respectively. No correlation was shown for CD4+. Within therapeutic groups, correlation with time was significant for CD4/CD8 in all groups and for CD8+ in SM and MX; no correlation was highlighted for CD4+. Normal values were reached at T30 in MA and at T90 in SM and MX. Correlation of CD4/CD8 and CD8+ with clinical improvement was present in MA and SM but not in MX. Regardless of clinical groups, the worst values of lymphocyte subsets were recorded in MX; MA showed the best values; significant differences between MA and MX were recorded. Within S, PR and CR the worst results were recorded in MX, the best in SM. Conclusions: all drugs induced CD4/CD8 normalization, faster and correlated to clinicopathological improvement in MA. MX showed a slower response and worst values of lymphocyte subsets. Follow up studies could point out if this response has prognostic significance.