DETECTION AND COMPARATIVE-ANALYSIS OF PERSISTENT MEASLES-VIRUS INFECTION IN CROHNS-DISEASE BY IMMUNOGOLD ELECTRON-MICROSCOPY

Aims-To determine the specificity of persistent measles virus infectio n in intestinal samples from Crohn's disease patients using quantitati ve immunogold electron microscopy. To compare the results with samples from ulcerative colitis, a granulomatous inflammatory control (tuberc ulous lymphadenitis), and a positive control. Methods-Formalin fixed, paraffin embedded intestinal tissue from patients with Crohn's disease was reprocessed and stained with antimeasles nucleocaspid protein pri mary antibody followed by 10 nm gold conjugated secondary antibody. Ti ssue samples were taken from granulomatous and non-granulomatous areas of the intestine. Intestinal samples from patients with ulcerative co litis, tuberculous lymphadenitis, or acute mesenteric ischaemia were s imilarly processed. Brain tissue from a patient with subacute sclerosi ng panencephalitis (SSPE) was used as the positive control. Duplicate sections of all tissues were processed without the primary antibody. S tained specimens were examined by electron microscopy. Results-In Croh n's disease patients, 8/9 foci of granulomatous inflammation and 0/4 f oci of non-specific inflammation were positive for measles virus. Of c ontrols, 0/5 non-inflamed intestinal tissues, 1/8 tuberculous tissues, 1/5 ulcerative colitis tissues, and 1/1 SSPE tissues were positive. G old grain counts per nuclear field-of-view in both Crohn's disease gra nulomas (43.29) and SSPE (36.94) were significantly higher than in tis sues from patients with ulcerative colitis (13.52) or tuberculous lymp hadenitis (15.875), and non-granulomatous areas of Crohn's disease (4. 89) (p < 0.001, p < 0.001, p = 0.0006, respectively), with no signific ant difference between Crohn's disease and SSPE (p > 0.1). In both SSP E and Crohn's disease staining was confined to a small population of c ells exhibiting characteristic cytopathology. Conclusion-These data su pport a role for measles virus in the aetiology of Crohn's disease.