Characteristics of patients with serum antibodies to extractable nuclear antigens

Abstract

A distinguishing feature of the mixed connective tissue disease (MCTD) syndrome is the presence in the serum of antibody in high titer to ribonucleoprotein (RNP). To determine whether this was an exclusive observation, a large rheumatic disease population was surveyed for the presence of antibody in high titer to extractable nuclear antigens (ENA) including RNP. Of 650 sera examined, 440 (from 240 patients) had antinuclear antibody. Only 39 patients had serum antibody to ENA in titers ≧ 1:200 dilution. In 16 the anti‐ENA was shown by RNAse digestion to be anti‐RNP. Although many clinical and laboratory characteristics were similar in these two groups, the patients more closely resembled the previously described MCTD syndrome and, importantly, less often had severe renal and central nervous system disease manifestations. Thus the presence of serum antibodies to ENA that are predominantly RNAse‐sensitive (anti‐RNP) helps to identify a rheumatic disease syndrome and also appears to have prognostic value.

Mixed connective tissue disease with associated glomerulonephritis and hypocomplementaemia

“…This further adds to evidence reported from several American centres (Bennett and Spargo, 1977;Farber and Bole, 1975;Fuller et al, 1977;Hench, Edgington and Tan, 1975;Leibfarth, McChesney and Persellin, 1975;Tan, Northway and Pinnas, 1973;Venkateswara et al, 1976) and recently from Paris (Gaudreau et al, 1978) that renal involvement does occur in MCTD. The case reported here is all the more unusual as, of those reported cases, only that by Fuller et al (1977) was definitely associated with hypocomplementaemia, the usual finding being normal or raised complement levels.…”

“…Of those reported membranous glomerulonephritis was recognized in 3 cases by Bennett and Spargo (1977) and one case each by Hench et al (1975) andFuller et al (1977) although the latter also contained some focal mesangial proliferative changes. Venkateswara et al (1976) reported a case with focal mesangial proliferative changes, and single cases of Leibfarth et al (1975) and Tan et al (1973) revealed focal proliferative and proliferative glomerulonephritic changes respectively. All these cases had glomerular deposits of complement and immunoglobulin.…”

Homozygous C2 deficiency with fulminant lupus erythematosus. severe nephritis via the alternative complement pathway

“…The present study would suggest that under appropriate conditions involvement of the properdin system may further result in severe and even fatal disease, although clearly this represents an unusual experience. It is of interest that the predominant antinuclear antibody detected was anti-RNP, which paradoxically has been described as modulating or protecting against glomerular injury induced by antibodies of DNA or Sm specificity (50)(51)(52). Whether anti-RNP can activate the alternative pathway and/or mediate disease preferentially when C2 is deficient is not yet known.…”

Survivorship in systemic lupus erythematosus. effect of antibody to extractable nuclear antigen

“…The demographic and clinical features of these 81 patients (Tables 2 and 4) were comparable to those noted in previous large series of SLE patients (6,10,11,13,14), suggesting that our study population was not skewed toward factors associated with milder disease or overlap features. We did not select individuals solely on the basis of certain antibody profiles, as has been done by others (17)(18)(19)22,23,25,26) in studying the effects of antiENA antibody. The subsets of the overall SLE patient group were defined solely on the presence or absence of antibodies to ENA and its RNP component, irrespective of clinical features or presence of antibody to deoxyribonucleic acid (DNA).…”