Background: Hepatic pruritus is a very common symptom among different chronic liver diseases, particularly in those related to cholestasis.   Its prevalence  is variable among liver diseases,   ranging from 5%  in chronic hepatitis  C virus infection to 70% in primary biliary  cirrhosis.  Its etiopathogenesis  remains  poorly understood. Nerve growth factor (NGF) is a member of neurotrophins.  many studies clearly demonstrate

their role in pruritus.  Nerve growth factor (NGF) is overexpressed in prurigo nodularis   and its therapeutic administration  is pruritogenic.  In atopic dermatitis,

NGF is released by keratinocytes, mast cells and fibroblasts  and plasma levels  of NGF

are also  elevated and correlate with disease activity. This study examines  the hypothesis  that expression  of NGF protein is altered in cirrhotic patients  with pruritus. Patients   and Methods:   To test our hypothesis,  we examined the expression  patterns of NGF protein in cirrhotic patients with pruritus, cirrhotic patients without pruritus and corresponding healthy (control).  skin biopsies (20 specimens each) were

evaluated using immunoperoxidase staining techniques.

Results:  We found variations between the skins of cirrhotic patients  with and without pruritus and healthy skin. In healthy skin, the expression  of NGF protein was strong (basal cell keratinocytes), moderate (spinous layer),  and weak or abscent  (granular

cell  layer). In contrast, marked expression  ofNGF protein  was observed in all layers of skin (total NGF epidermis  and dermis)  in cirrhotic  patients with pruritus in comparison with cirrhotic patients without pruritus and healthy control and this was statistically  significant.  NGF protein expression was strong (basal  cell keratinocytes), moderate (spinous layer), and weak or abscent (granular cell layer).  The expression of NGF protein was strong in the adnexal structures.

Conclusions:   We report, for the first time, increased  expression  of NGF protein in the

epidermal keratinocytes of cirrhotic patients with pruritus skin.  Our findings suggest possible roles for this protien in pathophysiology  of hepatic pruritus.  The clinical ramifications of these observations  mandate further investigations.