WHIPPLES-DISEASE - COMPARISON OF HISTOLOGY WITH DIAGNOSIS BASED ON POLYMERASE CHAIN-REACTION IN 4 CONSECUTIVE CASES

Background-Polymerase chain reaction (PCR) based detection of species specific sequences of the 16S rRNA gene of Tropheryma whippelii is a r ecently described method for diagnosis of Whipple's disease. Aims-Comp arison of histology with PCR in mucosal samples of patients with Whipp le's disease before, during, and after treatment. Detection of T whipp elii in peripheral blood mononuclear cells as a non-invasive test for infection. Methods-Four consecutive patients with histologically prove n Whipple's disease were studied prospectively. Results-In untreated p atients biopsy specimens taken from regions with PAS positive macropha ges gave a positive result with PCR for T whippelii; however, a PCR si gnal was also found in tissue biopsy specimens from mucosal regions wi th negative histology. In two of the patients the PCR performed with n ucleic acids extracted from peripheral blood mononuclear cells was pos itive. After treatment with sulfamethoxazole\trimethoprim the PCR beca me negative after one month in two patients and after two months in th e third patient treated, whereas PAS positive macrophages were found t hroughout the treatment period in two patients and disappeared in only one of them thereafter. Conclusions-Detection of T whippelii specific sequences based on the PCR is useful to confirm the diagnosis, is abl e to detect a positive signal in samples taken from histologically neg ative mucosal areas, and can be used to monitor treatment. The PCR can sometimes be positive in peripheral blood mononuclear cells, but this cellular compartment cannot be taken as a substitute for duodenal bio psy specimens in the diagnosis of Whipple's disease.