Expression of leptin, leptin receptor, and connective tissue growth factor in degenerative disk lesions in the wrist

The purpose of this study was to identify whether leptin and connective tissue growth factor (CTGF) occur in the degenerative fibrocartilage disk and whether cartilage cells express leptin receptors.

The study included 23 patients diagnosed with degenerative articular disk tears of the triangular fibrocartilage (TFC) (Palmer type 2C). Patients were divided into 2 groups based on ulna length: 1 group consisted of patients with an ulna-positive variance (group A), and the other group included patients with ulna-negative or -neutral variance (group B). After arthroscopic debridement of the TFC, histologic sections of biopsy specimens were prepared. The biopsy specimens were immunohistochemically analyzed, and the quantity of leptin-, CTGF-, and leptin receptor-positive cells was assessed.

Cells positive for leptin, leptin receptor, and CTGF were found. The number of cells positive for leptin was significantly increased in specimens of patients with an ulna-negative variance (group B). In contrast, no significant difference was found for leptin receptor and CTGF in biopsy specimens of patients with ulna-positive or ulna-negative/neutral variance. The inner, middle, and outer zones of the disk do not express significantly different quantities of marker-positive cells.

Degenerative fibrocartilage disk tissue cells exhibit leptin receptors and are exposed to the markers leptin and CTGF, providing evidence of a local paracrine system and regenerative processes. Cells of disks from patients with an ulna-neutral/negative length express significantly higher numbers of leptin-positive cells.

Level II, diagnostic study.