The Relationship between Cytomegalovirus Infection and Guillain–Barré Syndrome

Extract

(See the article by Orlikowski et al, on pages 837–844.)

The association between cytomegalovirus (CMV) and Guillain–Barré syndrome (GBS) was first noted in 1967 [1] and was soon endorsed by other reports and case series. The largest previous case series showed that CMV infection was associated with GBS in 8% of 229 patients from a European and North American trial [2]. In this issue of Clinical Infectious Diseases, Orlikowski et al [2] confirmed this finding in a larger population of people with GBS by using the resources of the French reference centre in Garches, Paris, which has been a major source of useful research into the disease. Of 506 patients with GBS, 63 (12.5%) had serological evidence of primary CMV infection. It is difficult to distinguish between primary and reactivation of infection, an important problem, because ∼50% of the nonimmunosuppressed people in developed countries have serological evidence of exposure to CMV. The serological methods used by Orlikowski and colleagues incorporated a test for high immunoglobulin (Ig) G avidity to exclude positive results due to reactivation. Low-avidity IgG antibody is found in primary infection before affinity maturation has occurred. The serological results were supported by the finding of CMV DNA in the plasma by polymerase chain reaction (PCR) in 36 (62%) of 58 subjects who had positive serological test results. The sensitivity of CMV PCR nears 100% for acute infection, but it would be expected to be reduced in the late infectious phase, when GBS occurs because virus is being cleared. Unfortunately no convalescent-phase samples were available for analysis because of the intervening treatment and quantitative PCR was not performed for enough patients to publish the result.