Clinical and immunological efficacy of immunomodulating hexapeptide associated with the restoration of CD11b⁺CD64^-CD32⁺CD16⁺ and CD11b⁺CD64⁺CD32⁺CD16⁺ neutrophil granulocytes subset in women with chronic infectious and inflammatory diseases of the pelvic organs

Failure of anti-infectious immune protection is considered a reason for the prolonged course and recurrence of chronic infectious and inflammatory diseases of pelvic organs (PID). Our aim was to evaluate the effect of an original hexapeptide (HP) on negatively altered subpopulations of neutrophil granulocytes (NG) CD11b⁺CD64^-CD32⁺CD16⁺ and CD11b⁺CD64⁺CD32⁺CD16⁺, their phenotype and associated effector functions in immunocompromised women with PID.

35 women (20-40 years old) with PID were studied during the period of clinical exacerbation (study group 1, SG1). Study group 1a (SG1a) consisted of patients who underwent treatment including the HP injections (45 mcg/ mL, 1 ml intramuscularly once a day for 10 days). The comparison group (CG) consisted of 20 conditionally healthy women. The numbers of CD11b⁺CD64^-CD32⁺CD16⁺NG and CD11b⁺CD64⁺CD32⁺CD16⁺NG cell subsets and the density of receptor expression, phagocytic and microbicidal function of NG were determined.

In SG1, decreased counts of the major NG subpopulation (CD11b⁺CD64^-CD32⁺CD16⁺NG) was revealed (p < 0.05), with a trend for increase of minor subset CD11b⁺CD64⁺CD32⁺CD16⁺NG (p > 0.05). In the CD11b⁺CD64^-CD32⁺CD16⁺NG subset, we noted a decreased expression of CD16 (1.4-fold), CD11b (2-fold) (p_{1, 2} < 0.05). In the minor subset CD11b⁺CD64⁺CD32⁺CD16⁺NG, the expression densities were decreased in CD16 (1.7-fold), CD11b (2.1-fold, p_{1, 2} < 0.05). At the same time, the phagocytic and microbicidal functions of NG were found to be decreased. In the course of immunomodulatory therapy with the HP-based drug, positive changes in immunological parameters were revealed. In SG1a, an increased number of major NC subset was observed, with an increase in the expression density of CD16 by 1.2 times, CD11b by 1.7 times relative to SG1 (p_{1, 2} < 0.05). The contents of minor NG subset tended to decrease, along with CD16 expression density reaching the indices of comparison group. CD11b increased 1.3 times relative to SG1 (p < 0.05). Higher ratios of actively phagocytizing NG and their killing ability have been registered. Clinically, we observed faster regression of clinical PID exacerbation symptoms and decreased frequency of relapses 6 months after treatment in 88.6% of cases. The positive immunomodulatory effects of the HP-based drug upon altered subsets of CD11b⁺CD64^-CD32⁺CD16⁺ and CD11b⁺CD64⁺CD32⁺CD16⁺ NGs, their phenotype and associated effector functions suggest an opportunity of its usage for the correction of NG dysfunctions in immunocompromised women with PID, thus providing stable clinical and immunological remission and protective effect.