Pitfalls in recommending evidence-based guidelines for a protean disease like Henoch–Schönlein purpura nephritis

Systemic vasculitis associated with autoantibodies to neutrophil cytoplasmic antigens (ANCA) is the most frequent cause of rapidly progressive glomerulonephritis. Renal failure at presentation carries an increased risk for ESRD and death despite immunosuppressive therapy. This study investigated whether the addition of plasma exchange was more effective than intravenous methylprednisolone in the achievement of renal recovery in those who presented with a serum creatinine >500 micromol/L (5.8 mg/dl). A total of 137 patients with a new diagnosis of ANCA-associated systemic vasculitis confirmed by renal biopsy and serum creatinine >500 micromol/L (5.8 mg/dl) were randomly assigned to receive seven plasma exchanges (n = 70) or 3000 mg of intravenous methylprednisolone (n = 67). Both groups received oral cyclophosphamide and oral prednisolone. The primary end point was dialysis independence at 3 mo. Secondary end points included renal and patient survival at 1 yr and severe adverse event rates. At 3 mo, 33 (49%) of 67 after intravenous methylprednisolone compared with 48 (69%) or 70 after plasma exchange were alive and independent of dialysis (95% confidence interval for the difference 18 to 35%; P = 0.02). As compared with intravenous methylprednisolone, plasma exchange was associated with a reduction in risk for progression to ESRD of 24% (95% confidence interval 6.1 to 41%), from 43 to 19%, at 12 mo. Patient survival and severe adverse event rates at 1 yr were 51 (76%) of 67 and 32 of 67 (48%) in the intravenous methylprednisolone group and 51 (73%) of 70 and 35 of (50%) 70 in the plasma exchange group, respectively. Plasma exchange increased the rate of renal recovery in ANCA-associated systemic vasculitis that presented with renal failure when compared with intravenous methylprednisolone. Patient survival and severe adverse event rates were similar in both groups.

To evaluate the efficacy of early prednisone therapy in preventing renal and treating extrarenal and renal symptoms in Henoch-Schönlein purpura (HSP) in a placebo-controlled trial. A total of 171 patients (84 treated with prednisone and 87 receiving placebo) were included and followed up for 6 months. The endpoints were renal involvement at 1, 3, and 6 months and healing of extrarenal symptoms. The analyses were performed on an intent-to-treat basis. Prednisone (1 mg/kg/day for 2 weeks, with weaning over the subsequent 2 weeks) was effective in reducing the intensity of abdominal pain (pain score, 2.5 vs 4.8; P = .029) and joint pain (4.6 vs 7.3; P = .030). Prednisone did not prevent the development of renal symptoms but was effective in treating them; renal symptoms resolved in 61% of the prednisone patients after treatment, compared with 34% of the placebo patients (difference = 27%; 95% confidence interval = 3% to 47%; P = .024). The general use of prednisone in HSP is not supported, but patients with disturbing symptoms may benefit from early treatment, because prednisone reduces extrarenal symptoms and is effective in altering (but not preventing) the course of renal involvement.

Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are considered to be related diseases since both can be encountered consecutively in the same patient, they have been described in twins, and bear identical pathological and biological abnormalities. Apart from the presence of extrarenal clinical signs found only in HSPN, other differences are noticed between the two diseases. The peak age ranges between 15 and 30 years for a diagnosis of IgAN, whereas HSPN is mainly seen in childhood. Nephritic and/or nephrotic syndromes are more often seen at presentation in HSPN. In contrast to IgAN, HSPN has been described in association with hypersensitivity. Endocapillary and extracapillary inflammations as well as fibrin deposits in the glomerulus are more frequent in HSPN. No major biological differences have been found between the two illnesses, except for a larger size of circulating IgA-containing complexes (IgA-CC) and a greater incidence of increased plasma IgE levels in HSPN. As tissue infiltration by leukocytes is a major feature of HSPN vasculitis, a possible role of a more potent activation of the latter cells by IgA-CC and/or circulating chemokines in HSPN should be considered. Further studies are required to elucidate this possible mechanism as well as the role of hypersensitivity in HSPN.