Analysis of procalcitonin and CRP concentrations in serum of patients with chronic spontaneous urticaria

BACKGROUND: Our previous findings showed the importance of analysing the peripheral markers of acute phase response (APR) activation, C-reactive protein (CRP) and IL-6 in the context of urticaria activity and severity. However, these biomarkers do not reliably differentiate between APR to infectious and the disease severity. AIM: In order to investigate a possible association between the immune-inflammatory activation markers CRP and procalcitonin (PCT). METHODS: Serum PCT and CRP concentrations were measured in patients with CU of varying severity as well as in healthy subjects. RESULTS: Serum PCT and CRP concentrations were significantly increased in more severe CU patients when compared to healthy controls and mild CU, and within the CU population there was a significant correlation between concentrations of PCT and CRP. Serum PCT concentrations remained within normal ranges in most CU patients and were only slightly elevated in some severe CU cases. CONCLUSIONS: PCT serum concentration may be only slightly elevated in some cases of severe CU. Upregulation of PCT synthesis accompanied by parallel changes in CRP concentration reflects a low-grade systemic inflammatory response in CU. PCT should be considered as a better marker than CRP to distinguish between APR to infection and an active non-specific urticarial inflammation.