Speckled (particulate) epidermal nuclear IgG deposition in normal skin. Correlation of clinical features and laboratory findings in 46 patients with a subset of connective tissue disease characterized by antibody to extractable nuclear antigen

Abstract

Clinical and laboratory findings were correlated from 46 patients with IgG localization in epidermal nuclei in a speckled (particulate) pattern on direct immunofluorescence of normal skin. Cutaneous manifestations included lupus erythematosus (LE), swollen hands or sclerodactyly, alopecia, vasculitis, and dyspigmentation. Systemic manifestations included arthritis or arthralgia, Raynaud's phenomenon, serositis, vascular headaches, mild renal disease, myositis, and sicca syndrome. High titer (mean = 1:142, 800) serum antibody to extractable nuclear antigen (ENA) was found in 81%. Eighty-six percent had antibody to an RNase-sensitive antigenic component of ENA (ribonucleoprotein or RNP); 14% had antibody to an RNase-resistant ENA termed Sm. Deposition of IgG in a speckled pattern in epidermal nuclei is an immunopathologic marker for a subset of connective tissue disease characterized by antibody to ENA. Those with Sm specificity had systemic LE (SLE); Those with RNP specificity had Raynaud's phenomenon usually associated with overlapping features of SLE, scleroderma, and/or dermatomyositis.

Clinicopathological evaluation ofin vivoepidermal nuclear fluorescence

“…The clinical relevance of in vivo ANA with CTDs has been shown in the literature, especially in those patients with high titres of anti‐ENA. The presence of anti‐ENA in 60% of our patients was compatible with other publications 13 16,17 The most common form of anti‐ENA reported in the literature is anti‐RNP, which was present in only eight of our patients 4,8,18,19 . In contrast, anti‐SSA/Ro ( n = 12) and anti‐SSB/La ( n = 11) were the most common autoantibodies detected in the patients positive for anti‐ENA in our group.…”

The specificity and clinical usefulness of the lupus band test

“…Virtually all patients with this disorder had high titers of antibody to ribonuclease-sensitive extractable nuclear antigen and high-titer speckled fluorescent antinuclear antibody. A band of immunoglobulins with or without complement components may be found, indistinguishable from that seen in SLE, in the frequencies shown in Table 1 (82)(83)(84)(85)(86). However, the number of cases from which these figures are abstracted is small.…”

An update on the pathogenesis of idiopathic inflammatory myopathies

“…Whether autoantibodies are pathogenic or are simply markers of the associated autoimmune response remains debated. Direct immunofluorescence on skin biopsies from patients with systemic lupus erythematosus (SLE) and systemic sclerosis showed nuclear immunoglobulin G (IgG) deposition that mirrored the ANA pattern (if the titer was sufficiently high) in very early studies [61,62]. This suggests that autoantibodies may be penetrating target tissue cells, though the possibility of an in vitro artifact due to tissue preparation cannot be excluded.…”