[Analytical interference in determination of procalcitonin by PCT-Q (Brahms)].

Procalcitonin (PCT) is a biological marker of infection. We present the cas of a patient who has presented a high concentration of PCT with PCT-Q test (Brahms). At the same time, the concentration of CRP is remained low, which is no physiological. Then, PCT concentration has been determinated with an automatic system (Kryptor-Brahms) and finded at low than 0.5 microg/l. Brahms company has searched an analytical interference: human anti-mouse antibodies (HAMA) were positive. If PCT concentration stay a marker of infection for the most part, this case show that biologists have to keep in mind that immunological assays remain submitted to interferences.