[Class IV-G and IV-S lupus nephritis, interstitial infiltrates and prognosis: state of the art and unmet medical needs].

Nephritis in systemic lupus erythematosus is one of the manifestations of organ damage in this autoimmune disease. Class IV is the most ominous among the classes of nephritides and there are conflicting reports on whether class IV-G lupus nephritis differs from class IV-S as defined by the International Society of Nephrology and the Renal Pathology Society (ISN/RPS) in terms of kidney and patient survival. There is, however, general agreement that 15-30% of patients with class IV nephritis do not reach remission and that a similar percentage (15-30%) of those reaching remission relapses. The presence of interstitial nephritis may be one of the determinants of a poor disease course. In fact, in recent years new data have emerged regarding the role of interstitial infiltrates in determining a poor outcome, but until now no data have been gathered on the differentiation of outcomes among class IV-G or IV-S with and without infiltrates.