Early detection of subclinical HIV sensory polyneuropathy using intraepidermal nerve fibre density quantification: association with HIV stage and surrogate markers

The linear intraepidermal nerve fibre density (IENFD) and secondary branching were evaluated from skin biopsy of both the distal calf and the proximal thigh after staining with protein gene product 9.5 in 94 individuals of an HIV outpatient cohort. Possible correlations with clinical and electrophysiological evidence of distal sensory polyneuropathy (DSP), patients' demographics, antiretroviral history and HIV surrogate markers were analysed. Reduced IENFD was recognized in the majority of this population (mean +/- standard deviation [SD] IENFD in the calf and the thigh was 3.19 +/- 1.91 and 7.07 +/- 3.5 fibres/mm, respectively). One-third of the patients with low IENFD had no clinical or electrophysiological evidence of DSIP, The level of prior immunosuppression as expressed by lower nadir CD4 count, more advanced HIV stage and prior exposure to combinations of neurotoxic antiretrovirals was associated with more decreased IENFD. Increased SIB was associated with symptomatic DSP.