Do B cells influence disease progression in chronic synovitis? Lessons from primary hypogammaglobulinaemia

We describe a 62-yr-old male patient with primary hypogammaglobulinaemia (P H) who fulfilled the 1987 American Rheumatism Association/American College of Rheumatology revised diagnostic criteria for rheumatoid arthritis (RA) b ut, despite persistent symmetrical synovitis, did not develop erosions. Vir ology studies and blood and synovial fluid (SF) cultures were consistently negative; a search for crystals in the SF was unrevealing. Peripheral blood (PB) B cells were absent, whilst the PB CD3(+) cell count was normal. The ratio of naive (CD45RA(+)) to memory (CD45RO(+)) cells was also normal (1:1 ) but the CD4:CD8 ratio was reversed. To our knowledge, this is the first r eport which combines the immunophenotypic analysis of the PB with that of t he SF and synovial membrane (SM). This confirmed the absence of B cells and the reversed CD4:CD8 ratio. However, as in other chronic arthropathies, th e SF and SM cellular infiltrate consisted almost exclusively of memory T ce lls, consistent with the preferential localization of this subset to inflam ed tissues. This case indicates that synovitis can proceed persistently in the absence of B cells and that the migratory mechanisms of T cells are not altered. However, the case suggests that the absence of B cells and negati vity for rheumatoid factor, combined with an increased presence of CD8(+) ( suppresser/cytotoxic) T cells in the joint, might contribute to the non-ero sive nature of the synovitis.