Anti-fibrillarin antibodies in systemic sclerosis

Objectives. To investigate the nature and extent of organ involvement in an ti-fibrillarin antibody (AFA)-positive patients within a UK systemic sclero sis (SSc) population. Methods. We investigated 1026 consecutive patients with SSc. AFA was identi fied by the characteristic clumpy nucleolar and coilin body pattern of stai ning in interphase cells and staining of fibrillarin in metaphase cells by indirect immunofluorescence using HEp-2 cells. Identity of the 34-kDa fibri llarin protein was confirmed by immunoprecipitation from [S-35]methionine-l abelled HeLa cell extract. Results. AFA was detected in 42 patients (4.1%) with early disease onset (m ean age 36 yr). Sixteen (38%) patients had limited cutaneous (lcSSc) and 26 (62%) diffuse cutaneous SSc (dcSSc). All eight Afro-Caribbean patients wit h AFA had dcSSc whereas the Caucasians were equally divided between dcSSc a nd lcSSc. Within the dcSSc subgroup, 54% had myositis, 35% had pulmonary hy pertension, 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.