MORPHOLOGICAL PARAMETERS IN LUPUS NEPHRITIS - THEIR RELEVANCE FOR CLASSIFICATION AND RELATIONSHIP WITH CLINICAL AND HISTOLOGICAL-FINDINGS AND OUTCOME

  • 1 January 1985
    • journal article
    • research article
    • Vol. 55  (217) , 153-168
Abstract
One hundred and sixty-seven renal biopsies from 147 patients with lupus nephritis were studied retrospectively to assess the contribution to morphological classification by features assessed with immunofluorescence and EM, together with pathological indices obtained by scoring specific histologic changes. The prognostic relevance of the histologic scoring was also evaluated. The biopsies were assigned to the following classes: I, absence of glomerular lesions; II, mesangial proliferation; III, focal segmental proliferation; IVa, diffuse (> 50 percent of the glomeruli) but segmentally distributed proliferation; IVb, diffuse and generalized proliferation; IVc, extracapillary proliferation; Va, pure membranous changes; Vb, membranous changes with slight mesangial proliferation; VI, association of class V and class III or IV. The incidence and degree of some glomerular and non-glomerular active and sclerotic changes as assessed by light microscopy were evaluated in the different classes. Both the activity and sclerosis indices obtained by scoring these lesions were significantly higher in classes with glomerular proliferative changes. Eighteen patients had a 2nd biopsy and 2 of these had a 3rd; more severe changes were observed in 9 and improvment in 4. In 146 biopsies light microscopy findings were compared with immunofluorescence patterns (negative, mesangial, mesangial and peripheral, peripheral, membranous). The mesangial pattern was mainly present in class II with a few examples in classes I and III; in the last 2 the mesangial-peripheral pattern was most common; the peripheral pattern was by far the most common in class IV (a, b and c) and frequent in class VI; a membranous pattern was the rule in class V and occasionally found in class VI. Ig and complement (C) fractions were simultaneously present in most cases, IgG, C3 and C1q being the commonest in all classes. Except for IgM and fibrinogen, the differences in distribution of Ig and C fractions among the various classes were statistically significant. The deposits most commonly found by EM in all biopsies were mesangial; subendothelial deposits were mainly found in classes with active glomerular changes, frequently associated with deposits at the other sites in the most severe cases. A highly significant correlation was found between the activity index and the sclerosis index and severity of the clinical picture at biopsy. An unfavorable progress was confined mainly to classes with extensive intracapillary proliferation and correlated significantly with the highest activity and sclerosis indices. Results confirm the validity and usefulness of the conventional light microscopy classification in lupus nephritis, although in individual patients the scoring system provides a more precise estimate of the type and course of the disease.