Procalcitonin in autoimmune disease with sepsis

Introduction

Procalcitonin (PCT), the precurser of calcitonin, is important as a marker of systemic bacterial, fungal and parasite infections. In patients with autoimmune diseases is the response of invasive infection difficult to discriminate from the underlying disease activity. To determine the specificity of procalcitonin, the present study investigated the relationship of immmunologic markers to PCT in systemic autoimmune diseases with sepsis.

Methods

Ten patients with systemic autoimmune disease (rheumatoid arthritis, systemic lupus erythematodes, sclerodermia) and sepsis of an Internal Intensive Care Unit, University hospital, were included. The severity of the disease was assessed at the APACHE II and SOFA-score. To determine the systemic inflammation were measured the serum concentrations of the C-reactive protein, procalcitonin, TNF-alpha, interleukin-6 and the leukocyte count during the septic process.

Results

There was a significant difference in TNF-alpha- and interleukin-6-level and procalcitonin during the systemic bacterial inflammation (P < 0.05). Only the marker procalcitonin was related to the clinical signs and the severity of disease. Also compared to the C-reactive protein and leucocyte count PCT showed a better association to the duration of sepsis.

Conclusion

These results indicate that Procalcitonin is in autoimmune diseases an important marker to discriminate sepsis from underlying disease activity. The measurement of TNF-alpha and interleukin-6 during sepsis in these diseases described the systemic inflammation but not specific the bacterial infection as compared to PCT.