Diagnostic and prognostic significance levels of tumor necrosis factor (TNF)-α serum and mRNA expression in patients with infected diabetic foot ulcers

Abstract

Background: Infected diabetic foot ulcer (IDFU) is among the most common complications of Type 2 diabetes mellitus (T2DM),  significantly leading to lower extremity amputation. Tumor Necrosis Factor-alpha (TNF-α) is a cytokine with pleiotropic effects on different  tissues. This study aimed to investigate TNF-α mRNA and serum levels in Egyptian patients with diabetic foot ulcers in  correlation with the risk and severity of IDFU.

Methods: We enrolled 100 patients with T2DM and 100 healthy subjects. All patients were subjected to thorough history taking, complete clinical and neurological assessment, and foot ulcers were examined for size, site, and  duration. The level of TNF-α was measured using an Enzyme-linked immunosorbent assay, and the TNF-α mRNA level was determined by  quantitative real-time PCR.

Results: there were significantly higher values of TNF -α mRNA and serum levels in patients with DFU  (4.69±0.97,19.7±6.12, P ˂0.001* respectively) compared to controls (0.92±0.084,3.57±0.52, P ˂0.001* respectively). There were significantly  higher values of TNF -α mRNA and serum levels in patients with IDFU (4.98±0.52,22.98±5.56, P ˂0.001* respectively) compared to patients  without IDFU (3.8±1.41,9.95±1.42, P ˂0.001* respectively). Serum and TNF-α mRNA levels were significantly positively correlated with the duration of diabetes, BMI, HbA1c, ESR, and WBC. Linear regression tests revealed that duration of diabetes, BMI, and WBC were the main  predictors of serum TNF-α levels, but only ESR was the main predictor of TNF-α mRNA levels, P ˂0.001*.

Conclusions: TNF-α mRNA and  serum levels are elevated in DFU and IDFU and positively correlate with the risk and severity of IDFU.