Evidence-based recommendations for immunosuppression in IgA nephropathy: handle with caution

In 1999, Nolin and Courteau [1] published evidence‐based recommendations (Table 1) for the management of IgA nephropathy (IgAN). They concluded that ‘… patients with mild histopathological changes, proteinuria over 3 g/day, and a creatinine clearance above 70 ml/min should be treated with prednisone for 4–6 months. An initial dose of 1 mg/kg/day is recommended, with alternate day administration and gradual tapering after eight weeks in response patients. Steroids reduce proteinuria (grade B recommendation) and stabilize kidney function (grade C) …’ [1]. These recommendations were based on a small randomized controlled trial by Lai et al. [2] as well as a retrospective [3] and a prospective controlled trial by Kobayashi et al. [4]. Nolin and Courteau also concluded that the therapeutic usage of cyclophosphamide, cyclosporin A and azathioprine was not supported by sufficient data and that ‘… hypertension should be treated promptly, if possible with an angiotensin‐converting enzyme inhibitor (grade B) …’ [1]. Therefore, apart from the treatment of hypertension, recommendations on immunosuppressive therapy were only given for a small group of patients, i.e. those with (almost) normal renal function and nephrotic‐range proteinuria. Have we advanced in 2002?