Objectives: To investigate the nature and extent of organ involvement in anti-fibrillarin antibody (AFA)-positive patients within a UK systemic sclerosis (SSc) population.
Methods: We investigated 1026 consecutive patients with SSc. AFA was identified by the characteristic clumpy nucleolar and coilin body pattern of staining in interphase cells and staining of fibrillarin in metaphase cells by indirect immunofluorescence using HEp-2 cells. Identity of the 34-kDa fibrillarin protein was confirmed by immunoprecipitation from [(35)S]methionine-labelled HeLa cell extract.
Results: AFA was detected in 42 patients (4.1%) with early disease onset (mean age 36 yr). Sixteen (38%) patients had limited cutaneous (lcSSc) and 26 (62%) diffuse cutaneous SSc (dcSSc). All eight Afro-Caribbean patients with AFA had dcSSc whereas the Caucasians were equally divided between dcSSc and lcSSc. Within the dcSSc subgroup, 54% had myositis, 35% had pulmonary hypertension, 15% had cardiac involvement and 23% had renal involvement.
Conclusions: AFA identifies young SSc patients with frequent internal organ involvement, especially pulmonary hypertension, myositis and renal disease. In contrast to previous reports, AFA was not restricted to dcSSc patients in Caucasians.