INCREASED FREQUENCIES OF HPRT MUTANT T-LYMPHOCYTES IN PATIENTS WITH GUILLAIN-BARRE-SYNDROME AND CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY - FURTHER EVIDENCE FOR A ROLE OF T-CELLS IN THE ETIOPATHOGENESIS OF PERIPHERAL DEMYELINATING DISEASES

We have used the HPRT mutant clonal assay to determine the frequency o f mutant T lymphocytes (FMC), as a measure of recent T cell stimulatio n, in the blood of patients with Guillain-Barre syndrome (GBS) and chr onic inflammatory demyelinating polyneuropathy (CIDP). We found that, compared to healthy controls, the FMC in patients with GBS (16) and CI DP (10) was significantly increased in the progressive phase of the ne uropathy. FMC returned to normal values during recovery, suggesting a relationship between FMC and disease activity. No correlation was foun d between FMC values and motor deficit or severity of the neuropathy. The FMC of the GBS patients with a history of infection before onset o f neurological symptoms or with insufficient respiration was not signi ficantly different from the other GBS patients. Immunophenotypic analy sis showed that the fraction of CD8(+) HPRT mutant T cell clones was s ignificantly increased in GBS patients (48%) compared to healthy contr ols (3%) or CIDP patients (4.5%). Our results are compatible with the notion that T cells are involved in the pathogenesis of demyelinating inflammatory neuropathies.