The Association of Uremic Pruritus with Blood Lead Level in Prevalent Hemodialysis Patients through Systemic Inflammation

Abstract

Abstract Back ground and objective Pruritus is a common and often distressing symptom in patients with chronic kidney disease. Though the pathogenesis of uremic pruritus remains poorly understood, however systemic inflammation is one of the possible pathogenesis of uremic pruritus, and blood lead level has been noted to be associated with inflammation and nutritional status in long-term hemodialysis patients. There might be an interaction or association, therefore, between blood lead level and uremic pruritus through systemic inflammation. Blood lead level in hemodialysis patients might increase the intensity or have an additive role of pruritus caused by other more common risk factors. This study aims to further verify or deny the relation between blood lead level and uremic pruritus. Design, setting, participants, & measurements The present study is a cross sectional study that investigates the relation between blood lead levels and pruritus in patients with end stage renal disease receiving hemodialysis. 50 patients were enrolled in this study, all were on regular hemodialysis 3 times a week, patients with primary skin diseases (psoriasis, erythroderma, etc), HCV positive patients, patients with chronic liver disease and patients with malignancies were excluded. Patients with PTH levels over 300 pg/dl And those with corrected calcium and phosphorus levels over 10.2 and 5.5 mg/dl Were excluded from the study. We divided the patients into 2 groups, group 1 (n = 10) with no pruritus and group 2 (n = 40) with varying degrees of pruritus. Results There was a significant difference in serum lead levels and ferritin levels between group 1 and 2. Group 2 was further divided according to intensity of Pruritus by VAS score into mild (n = 10), moderate (n = 20) and severe pruritus (n = 10) There was also a statistically significant difference in serum lead levels in different groups of intensity of pruritus, having higher serum lead levels in patients who exhibited severe pruritus. And there was a significant correlation between blood lead and duration of dialysis Conclusion Uremic pruritus is a multi-factorial phenomenon, our study showed that Blood lead level in HD patients might increase the intensity and have an additive role in the pathogenesis of pruritus in dialysis patients hence Blood lead level is positively correlated with Uremic Pruritus. We were able to demonstrate that both blood lead and duration of dialysis together are the most sensitive predictors for pruritus, the best cut off value for blood lead is 6 together with duration above 10 with high sensitivity, specificity and efficacy.