Even mild cases of paediatric Henoch-Schönlein purpura nephritis show significant long-term proteinuria.

AIM: Henoch-Schonlein purpura (HSP) is a common cause of paediatric renal disease in children, representing 10-15% of paediatric glomerulonephritis. This study examined the long-term outcome of biopsy-proven HSP nephritis to identify correlations between disease development and treatment. METHODS: Patients from three French centres were retrospectively analysed. RESULTS: We followed up 142 patients aged from 2 to 10.5 years with HSP nephritis, graded according to the International Study Group of Kidney Disease in Childhood classification. Mean (±SD) age at presentation was 7.6 ± 2.8 years. Nephrotic range proteinuria was present in 28% of patients with Grade II lesions, 60% with Grade III and 90% with Grade IV. Significant proteinuria (>0.5 g/L) was found in nine of 48 patients 3 years after renal biopsy, eight of 25 patients after 5 years and three of 14 patients after 10 years. There was no correlation between the proteinuria risk at 3, 5 or 10 years and the initial histological lesion or treatment modality. Treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARB) was linked to lower proteinuria, especially if it was started precociously. CONCLUSION: Even mild forms of HSP nephritis risk significant long-term proteinuria. Very early introduction of ACEi/ARB may improve the long-term outcome independent of histological lesions.

Does rituximab induce hypogammaglobulinemia in patients with pediatric idiopathic nephrotic syndrome?

BACKGROUND: Rituximab (RTX) is a promising strategy for treating steroid-dependent idiopathic nephrotic syndrome (SDNS). RTX induces profound B-cell depletion, suggesting hypogammaglobulinemia as a potential side effect after long-term treatment. PATIENTS AND METHODS: We analyzed immunoglobulin G (IgG) levels in 12 pediatric patients on RTX with a B-cell depletion of a minimum of 3 months and compared the results to 16 patients on orally administered immunosuppressive drugs, such as mycophenolate mofetil (MMF) and/or cyclosporine A (CyA). All patients were in stable remission of SDNS at the time of IgG analysis. RESULTS: IgG levels in the RTX group before RTX introduction were 6.2 ± 1.0 g/L and were not significantly different from the MMF/CyA group (8.2 ± 2.5 g/L). In the MMF/CyA group, five patients had at least one episode of hypogammaglobulinemia. In two of them, this episode was prolonged (>3 months), and only one required IgG supplementation. In the RTX group, eight patients had decreased IgG levels before RTX infusion. After RTX, hypogammaglobulinemia persisted in seven among those eight patients. No decreased IgG plasma levels were noted in patients with normal baseline IgG levels before RTX treatment. CONCLUSION: RTX does not seem to directly induce decreased IgG levels in patients with SDNS, but it seems to prolong a preexisting low IgG levels.

Childhood onset diabetes posttransplant in a girl with TCF2 mutation.

Heterozygous mutations of TCF2 (transcription factor 2) have been associated with maturity onset diabetes of the young, renal malformations, hyperuricemia, and occasionally internal genital malformations in female. We report a female patient with bilateral renal hypodysplasia and de novo heterozygous TCF2 gene mutation. At the age of 9 yr, she developed transient ketoacidosis immediately posttransplant, temporarily requiring insulin. During glucocorticoid tapering, impaired glucose tolerance persisted and overt insulin-dependent diabetes mellitus developed 1 yr later. Pathogenic factors which might have played a role in the acceleration of diabetes were (i) switch from cyclosporine to tacrolimus, (ii) weight excess, and (iii) cytomegalovirus infection. TCF2 analysis might, therefore, be of interest in patients with congenital abnormalities of the kidney and the urinary tract in order to improve posttransplant management in terms of steroid and tacrolimus exposure.

Acute tubulointerstitial nephritis.

Acute tubulointerstitial nephritis (TIN) is a frequent cause of acute renal failure, characterised by the presence of inflammatory cell infiltrate in the interstitium of the kidney. Immuno-allergic reaction to certain medications, mainly non-steroidal anti-inflammatory drugs and antibiotics are by far the most important etiology for TIN today, but other situations such as infections, toxins, and vasculitis are known to induce TIN. Incidence of TIN is increasing, probably due to prescription habits and NSAID overuse, representing 3-7% of acute kidney injury in biopsies in children. Avoidance of the causal substance and rapid steroid therapy are hallmarks for patient care, but spontaneous initial recovery is very frequent and the general prognosis seems satisfactory. However, development of chronic TIN, without response to steroid or other immunosuppressive treatment, is possible. As the largest part of TIN is secondary to certain drugs, clear indications in particular for NSAID or antibiotics should be respected to reduce the number of TIN cases.