IgG reactivities directed toward lamin A/C. (A) Areas of 2-D membranes with IgG reactivities directed toward lamin A/C in sera from patients with different subsets of SSc and from healthy blood donors in total or nuclear (*) protein extracts from HEp-2 cells. (B) 2-D silver-stained gel of HEp-2 cell total protein extract. The areas delineated by rectangles correspond to the region of membranes magnified in A (pH 6.7 to 7.3; 75 to 80 kDa). (C) 3-D representation of IgG reactivity peaks in a sera pool from three patients (left) and from the 12 healthy blood donors (right). (D) IgG reactivities directed toward lamin A/C in enriched nuclear protein extract in the sera pool from patients with lcSSc, DU and unidentified ANA. ACA: anticentromere antibody; ANA: antinuclear antibody; ATA: antitopoisomerase I antibody; dcSSc: diffuse cutaneous systemic sclerosis; DU: digital ulcer; lcSSc: limited cutaneous systemic sclerosis; MW: molecular weight; PAH: pulmonary arterial hypertension; RNAP: anti-RNA polymerase III antibody; SRC: scleroderma renal crisis; SSc: systemic sclerosis.