Lymphocyte TRPV 1-4 gene expression and MIF blood levels in a young girl clinically diagnosed with HSAN IV.

OBJECTIVE: Patients with congenital insensitivity to pain are unable to sense pain and temperature. They undergo many injuries, inflammatory state, and infections. Various mutations in the neurotrophic tyrosine kinase receptor gene have been implicated in this disorder. We measured the leukocyte expression of transient receptor potential vanilloid (TRPV) 1-4 genes and the blood macrophage migration inhibitory factor (MIF) concentration in a young girl clinically diagnosed with congenital insensitivity to pain. The investigation may help to define the interplay between nerve growth factor and TRPV 1-4 channels and between these sensors and MIF in this disease, and in broader terms in nociception. METHODS: TRPV 1-4 gene expression (real-time polymerase chain reaction) and MIF concentration (enzyme-linked immunosorbent assay) were determined in the blood of the girl, her family, and control participants. Statistical analysis of gene expression was carried out between samples and controls with a mathematical model based on the correction for exact polymerase chain reaction efficiencies, and the mean crossing point deviation between samples and controls. RESULTS: The TRPV 1--4 gene expression rates did not significantly differ from the values found in the control group. TRPV1 was almost doubly upregulated. MIF levels were much higher than the reference value. DISCUSSION: The high increase in the MIF concentration (likely due to the chronic or recurrent inflammatory state) may have contributed to the normal expression of TRPV 1-4 and to the relative upregulation of TRPV1. The role of this cytokine on the expression of these genes deserves further investigation.