Virus serology in familial Crohn disease

Background: Recent findings that early-in-life virus infections represent a risk factor for Crohn disease, that exacerbations of disease sometimes app ear associated with common viral infections, and, in particular, suggestion s that Crohn disease may be the result of persistent infection with measles virus prompted serologic studies for antibody to 19 common viruses, Chlamy dia psittaci, and Mycoplasma pneumoniae. Methods: Sera from 14 affected mem bers of 2 French families with a high frequency of Crohn disease and from a ge- and sex-matched controls, taken in 1990 and 1992, and from unaffected f amily members were rested. Complement fixation, enzyme immunoassay, and ind irect immunofluorescent tests were used. Results: There were no significant differences between patients and controls or between affected and unaffect ed family members of family 2, with the exception that affected siblings ca rried higher antibody titers for mycoplasma one year and for varicella anot her year. There were no differences in measles IgM and IgG or mumps IgG ant ibody levels between patients and controls, or between patients and unaffec ted family members. Conclusions: Serology failed to find evidence of partic ipation by 19 common viruses, C. psittaci, and M. pneumoniae in Crohn disea se. The data do not support the hypothesis that persistent measles virus in fection causes Crohn disease.