Background: Chronic renal failure or chronic renal disease (CRD) is a progressive oss in renal function over a period of months or years. It is differentiated from acute kidney disease in that the reduction in kidney function must be present for over 3 months Uremic pruritus is the most common cutaneous abnormality in patients with CRF Uraemic pruritus is unrelated to sex, age, duration, cause of dialysis, a list of unproven suggestions for pruritis include : dry skin; mast cell proliferation; Thl cytokines; secondary hyperparathyroidism; disturbed balance between µ-opioid and K• opioid receptors; substance P; increased skin ions Ca, Mg, PO; abnormal transmission via the spine .
Nerve growth factor is a neurotropic polypeptide necessary for the survival and growth of some central neurons, as well as sensory afferent and sympathetic neurons.
It has been found that in AD patients increased levels of NGF in keratinocytes and nfiltrating leukocytes which were related to disease severity . Skin from patients with prurtigo nodularis also have increased presence of NGF which is primarily found in infiltrating leukocytes.
Method: The present case-control study was carried out on 30 patients with CRF and uraemic pruritus on hemodialysis who were treated at Sohag Educational Hospital and
20 healthy control subjects. Patients with CRF and uremic pruritus on hemodialysis of both sex, any age and not received any systemic treatment for pruritus for at least 3 weeks prior to the study were included in this study.
Severity of itching was measured by the 5-D itch score. 5-D is (duration - degree -
direction -disability and distribution). Maximum score is 25 and indicate severe itching while the minimum score is 5 and indicate no itching. Skin punch biopsies (3 mm) were taken from them for immunohistochemical studies.
Results: The present study found that in the skin of the healthy control participants the expressions of NGF were seen in the epidermal basal layer, but there was no expression in upper and mid epidermal cell layers while in dermis about 7 5% of them showed mild expression and 25% showed moderate expression.
In patients with chronic CRF with pruritus on dialysis the expressions of NGF were strong in epidermal basal layers, upper and mid epidermal layers. There was a strong expression of NGF in dermis with some spindle like infiltrating cells especially in dermal papillae.