Local expression of inflammatory cytokines in the facial tissue of children with a cleft lip and palate

Abstract

The cleft lip and/or palate are among the most common congenital anomalies that occur in early development. Cytokines play an important role in the proliferation, growth, differentiation, survival and the functional activity of many cells and the upregulation of cytokines might be involved in the pathological processes of the maxillofacial region. The purpose of our study was to evaluate the expression of pro-inflammatory and anti-inflammatory cytokines in the facial tissue of children with the cleft lip and palate.
The study involved 14 patients with the unilateral cleft lip and palate at the age of three months to 10 years and five months. Soft and hard palate tissue samples were collected during the primary cleft operation if the parents had given their informed written consent. All the tissue samples were stained with hematoxylin and eosin and by immunohistochemistry for IL-1α, IL-6, IL-8, IL-10 and TNF-α. The intensity of immunostaining was graded semiquantitatively.
IL-1α containing structures were not detected in any of soft, cartilage and bone tissue samples, meanwhile IL-6, IL-8, IL-10 and TNF-α showed explicit expression. The expression of IL 6 was observed in the tissues of all the patients. IL-6 positive cells were found in the range from no positive to moderate of positive structures in the visual field. IL-8 positive osteocytes were found in the range from few positive to moderate, but IL-8 positive chondrocytes were found in abundance. IL-10 was richly secreted by osteocytes in bone and by chondrocytes in cartilage obtained from all the cases of plastic surgery. In all the cases we also observed numerous IL-10 positive gingival epithelial cells. Despite these data obtained, moderate to numerous macrophages and neutrophils expressed TNF-α.
The sporadical and scarce expression of IL-6 indicates its insignificant role in the cleft lip and palate affected tissue. Rich cytokine IL-10 expression proves the compensated local anti-inflammatory effects of the cleft affected soft and hard tissue.