Increased systemic levels of centrally acting B-type Natriuretic Peptide are associated with chronic Itch of different types.

B-Type natriuretic peptide (BNP) is an itch-selective neuropeptide that was shown to play a role in both histaminergic and non-histaminergic itch in mice. It was also shown that elevated serum BNP is linked to increased pruritus in non-diabetic hemodialysis patients. This study examined plasma BNP levels of 77 patients and N-Terminal pro-BNP (NT-proBNP) levels of 33 patients with differing types of chronic itch to see if BNP and NT-proBNP levels can correlate with itch severity. Plasma BNP and NT-proBNP levels of all itch patients correlated to itch NRS, and in particular for patients with Chronic Pruritus of Unknown Origin (CPUO). Based on this clinical observation, this study further showed that increasing pathophysiological levels of BNP in mice by IV or osmotic pump induced significant scratching. Additionally, pharmacological and ablation strategies determined that BNP acts centrally by activating the natriuretic peptide receptor A (NPRA) in the dorsal horn of the spinal cord. These data support that BNP and NT-proBNP levels are associated with chronic itch and may be used in clinical setting.