Tissue indicators of inflammation in the cleft affected tissue

Orofacial clefts are one of the most common congenital anomalies worldwide, with the incidence of approximately 1 in 500-550 births. Moreover, morphogenesis and pathogenesis of the cleft lip are not completely understood yet. Whilst the ratio of macrophages (M)1 and M2 has been examined in other pathologies; there has been limited research done regarding the significance of the M1/M2 ratio in cleft affected tissue. Furthermore, due to TNF-α functions and its and macrophages effect on each other, it is also a factor of interest concerning orofacial clefts. Therefore, the aim of this work was to examine the appearance and distribution of M1, M2 and TNF-α, as well as deduce any possible intercorrelations between the three factors in cleft affected lip tissue samples. In the study participated 20 children with clefts. The samples of soft tissue were collected during plastic surgery. Fourteen control tissue samples, which were not associated with an orofacial cleft, were obtained during labial frenectomy. Tissues were stained for M1, M2 and TNF-α immunohistochemically. Nonparametric statistics, Mann-Whitney U and Spearman’s tests were used. A statistically significant difference in the distribution of the particular factor between the patient group and control group was observed only in regards to M1 (p=0,0002). Furthermore, whilst a weak correlation was observed between M2 and TNF-α (R=0,261), but a moderate correlation between M1 and M2 (R=0,503) as well as M1 and TNF-α (R=0,433), only the correlation between M1 and M2 was statistically significant (p=0,024). An increase of M1 and their difference between the patients and control along with the increase of TNF-α do suggest a more pro-inflammatory/inflammatory environment in the cleft affected tissue. However, the rise in M2 alongside M1 in one patient’s tissue sample could indicate an intensification of protective mechanism, which helps avoid extensive tissue damage.