Increased nerve growth factor mRNA in lateral calf skin biopsies from diabetic patients

Aims This study set out to establish a novel procedure for the measurement of human nerve growth factor (NGF) messenger ribonucleic acid (mRNA) and to use this method to measure NGF expression in skin biopsies from control su bjects and from patients with early neuropathies. NGF mRNA levels were rela ted to functional measures of the competence of NGF-responsive nerves. Methods mRNA levels were measured by competitive reverse transcription with polymerase chain reaction amplification (cRT-PCR). Functional correlates o f this observation were assessed by indices of thermal sensitivity - mediat ed by C-fibres, whose phenotype is regulated by NGF. Results NGF mRNA was increased in skin biopsies from 19 diabetic patients ( 5.12+/-3.88 (sD)) compared with samples from eight controls (1.57+/-0.95; P =0.001). Diabetic patients showed significantly (P<0.001) diminished detect ion of cool and warm stimuli compared to age matched control group (n=24), but there were no differences in detection of heat as pain, or correlation with NGF mRNA levels. Conclusions These findings suggest abnormally increased expression of NGF i n diabetic neuropathy, which may represent a compensatory mechanism for imp aired phenotype in NGF-responsive neurones.