Evaluation of lymphocytes subpopulations and natural killer cells in peripheral blood of patients treated for dermatophyte onychomycosis

Summary.  Thirty‐five patients with dermatophyte onychomycosis caused by Trichophyton rubrum, T. mentagrophytes var. granulosum, T. tonsurans and Epidermophyton floccosum were examined before treatment and 27 of these patients were examined again when they came to the control check up 3 months after completion of treatment. The immunological investigations, including evaluation of immunological competence, were performed in vivo through the determination of lymphoid cell immunophenotype by a flow cytometry technique. The quantitative composition of basic lymphocyte subpopulations and natural killer cells in the peripheral blood of 35 patients before the treatment was compared with a control group of 20 individuals. Statistically significant differences in the percentages of CD3+ T lymphocytes (P < 0.05), T helper lymphocytes (CD4+) (P < 0.05) and activated T lymphocytes (CD3+/HLA‐DR+) (P < 0.05) were obtained. In the control check‐up examinations of 27 patients 3 months after completion of treatment, in comparison with the control group of 20 healthy individuals, highly statistically significant differences in percentages of T lymphocytes (CD3+) (P < 0.001) and T helper lymphocytes (CD4+) (P < 0.01) were obtained. In five of these 27 patients the treatment resulted in failure. Comparing the group of 22 recovered patients with these five patients in whom the treatment result was failure, the only statistically significant difference obtained before as well as after the treatment was in B lymphocytes (CD19+) percentage (P < 0.05). The results obtained confirm that impairments of the patients' cellular immunity are crucial factors influencing the course and results of treatment in dermatophyte onychomycosis.