Bilal Aoun

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.

Polysaccharide pneumococcal vaccination of nephrotic children at disease onset - long-term data.

Sirs, Patients with nephrotic syndrome (NS) are at risk of developing pneumococcal infections, such as peritonitis, pneumonia ± pleural effusion, and meningitis [1], with the reported incidence of such infections population being 3– 5% per year [1]. There is currently no consensus on how to prevent severe episodes of pneumococcal infections in NS children. Anti-pneumococcal vaccine is given to such patients in many centers, but the fear of relapse induced by the vaccine still causes many pediatricians to hesitate in prescribing this treatment. We have recently reported that early treatment with 23valent INS pneumococcal vaccine (23PPV) at disease onset (in patients receiving high-dose steroids and with nephrotic proteinuria) induces a high antibody response [2]. An approximately tenfold increase in PPV23 antibody level at 1 month (M1) post-vaccination was followed by a decline for up to 6 months (M6) post-vaccination and stabilization at 12 months (M12) post-vaccination. This led us to question of whether the M12 levels remain stable or continue to decline until 36 months (M36) post-vaccination. We also investigated the impact of the number of relapses, immunosuppressive treatment, and patient age on the development of antibody levels [3]. Here, we report 23PPV specific antibody levels at M12 and M36 post-vaccination. This was a prospective study on long-term anti-PPV23 antibody levels after the early PPV23 vaccination of patients at the onset of NS. All patients who were included in our first study [2] (investigation of initial antibody response to PPV23) were considered for inclusion in this study. All patients received a unique dose of PPV23 either at disease onset when on high-dose steroids or in remission when on low-dose steroids every other day. Those children who had received 7-valent anti-PV during their first 2 years of life or who had proven invasive pneumococcal infection at disease onset were not included in the study. We compared patients who received PPV23 at disease onset (group 1) with those who received the vaccine when in remission and/or receiving low-dose alternate-day steroids (group 2). From 2004 until 2006, all children >2 years presentingwith a first manifestation of idiopathic NS (group 1) were considered for inclusion. Once NS had been diagnosed, global 23-valent PV antibody levels were determined on the same day, and treatment with oral prednisone was started at 60 mg/m per day, with a maximum dose of 60 mg/day. Once the oral steroid treatment started, the patients received one injection of 23-valent anti-PV (Pneumo 23; Merck, West Point, PA) 0.5 ml. Group 2 consisted of all children seen in our out-patient department with a NS in remission who were either receiving low-dose alternate-day prednisone therapy (≤ 15 mg/m) every other day or were without steroids, with or without other immunomodulatory treatments. Twenty-one patients (five girls) were included in the study. Eight patients received the vaccine when in remission on low-dose steroids (group A) and 13 received the vaccine at disease onset when receiving high-dose steroids (group B). B. Aoun :H. Wannous : C. Azéma : T. Ulinski (*) Department of Pediatric Nephrology, Armand-Trousseau Hospital, Assistance Publique–Hôpitaux de Paris (APHP), Avenue du Docteur Netter, 75012 Paris, France e-mail: tim.ulinski@trs.aphp.fr

Neutropenia in congenital nephrotic syndrome of the Finnish type: role of urinary ceruloplasmin loss

To the editor: Mechanisms for neutropenia are diverse and incompletely understood. Copper is an essential mineral that is absorbed in the intestine, bound to a carrier protein, transported to the liver, and then stored. Approximately 95% of copper found in the blood is bound to ceruloplasmin.

Therapy-resistant anaemia in congenital nephrotic syndrome of the Finnish type—implication of EPO, transferrin and transcobalamin losses

Congenital nephrotic syndrome of the Finnish type (CNF) is due to NPHS1 mutation and is responsible for a variety of urinary protein losses. We report the case of a 4-month-old girl with a particularly severe form (proteinuria approximately 150 g/l) of CNF. She developed severe non-regenerative anaemia requiring bi-monthly blood transfusions despite daily EPO (600 UI/kg) and iron supplementation. Epoetin pharmacokinetics revealed a urinary loss of 27% of the given dose within the first 24 h after IV injection. However, plasma levels remained increased after 24 h (228 UI/l). Plasma transferrin and transcobalamin levels were undetectable. Atransferrinaemia and atranscobalaminaemia seem to be responsible for disturbed erythropoiesis.

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

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.

Immunoadsorption: A New Strategy to Induce Remission in Membranous Lupus Nephritis

We report the case of an 11-year-old previously healthy girl who presented for microscopic hematuria and nephrotic proteinuria with normal renal function, which persisted after 6 months of steroids, angiotensin-converting enzyme inhibitors (ACEi)/angiotensin receptor blockers, hydroxychloroquine, mycophenolic acid and a low-salt diet. A serum investigation suggested lupus nephritis and a renal biopsy, performed 2 weeks after the first proteinuria detection, revealed membranous lupus nephritis. We decided to perform ten sessions of daily immunoadsorption. Proteinuria decreased significantly over these ten sessions from 8 to 0.12 g/l. After the tenth immunoadsorption session, the patient received the first rituximab (RTX) infusion leading to complete B-cell depletion. The patient was maintained on ACEi associated with mycophenolic acid and hydroxychloroquine. Three RTX reinjections were performed when CD19-positive cells reappeared in peripheral blood. Despite complete B-cell recovery and positive anti-dsDNA-Ab, the patient remained in complete remission 18 months after the initial diagnosis with negative proteinuria and a normal renal function.

Do vitamin D plasma levels impact vaccine response in children with idiopathic nephrotic syndrome

Dear Sirs,We have previously shown that pediatric patients with ne-phrotic syndrome have a high serological response after 23-valent pneumococcal vaccination [1]. The response was notdifferent in those who received the vaccine in remissionwithout steroids and those who received the vaccine whilehaving nephrotic proteinuria and high dose steroids. How-ever, the anti pneumococcal antibody response 1 monthpost-vaccination ranged from a 2- to 50-fold increase. Thisheterogeneous response was not explained by patient age,plasma albumin levels, or concomitant immunosuppressivetreatment [1].Vitamin D (Vit D) analyses were performed on serumsamples taken at the time of vaccination and kept at −20 °C.We analyzed 1,25-(OH)

Ureteropelvic Junction Obstruction and Parathyroid Adenoma: Coincidence or Link?

Congenital ureteropelvic junction obstruction (UPJO) is the most common cause of upper urinary tract obstruction in children. It is generally diagnosed in the routine work-up during antenatal period and is characterized by spontaneous recovery. It can be associated with urolithiasis; hence further investigation should be carried out. We report the case of a 15-year-old boy, who is known to have right UPJO, presented with right renal colic and discovered to have bilateral kidney stones. Further studies showed primary hyperparathyroidism and genetic analysis revealed a CDC73 mutation (initially HRPT2). We believe that association of UPJO and PHPT is a rare coincidence that can be linked. Careful work-up of children with UPJO and urolithiasis is recommended to exclude an underlying metabolic disease. Surgical correction can be evitable as treatment of the primary cause can lead to complete dissolution of kidney stones and improvement of the medical condition.

Rapid and sustained recovery of renal function with transient placement of an intrauretral nephrostomy catheter in an infant with ureteropelvic junction obstruction and acute renal failure.

Ureteropelvic junction obstruction (UPJO) is a common, congenital urinary malformation in the pediatric age group. In most cases the diagnosis is made antenataly and resolves spontaneously. Postnatal diagnosis is made when symptoms of urinary tract infection or abdominal pain occur. We report a six-month-old girl with single kidney and known vesicoureteral reflux grade IV presenting with severe acute renal failure (ARF), requiring acute peritoneal dialysis (PD).After diagnosis of decompensated UPJO, a nephrostomy was performed, and renal function restored within seven days. UPJO was subsequently treated by open pyeloplasty. To our knowledge, this is the first case of UPJO requiring PD due to severe renal failure in a child. Children with UPJO and major morbidity of the contralateral kidney are at risk of renal failure and should therefore be followed carefully to prevent serious complications.

A patient with acute urinary retention of unknown origin—questions

A 16-month old female child presented with a 1-day history of urinary retention. As for the past medical history, the mother noted chronic constipation since the age of 2 months, which was treated by laxatives. On presentation the patient was alert and active without signs of peripheral edema. Upon admission she had normal vital signs, a blood pressure of 100/80 mm Hg, a body weight of 9 kg, and normal height for age. Upon physical exam, the patient had abdominal distension and diminished deep tendon reflexes (DTR) in the lower limbs. Biochemical investigations showed a normal kidney function with a serum creatinine of 35 μmol/l, normal electrolyte concentrations, and normal liver function tests. Complete blood count was normal except for hemoglobin (Hb) of 8 mg/dl. The girl had a Foley catheter inserted and instantaneously passed urine. Urine analysis showed a specific gravity of 1.020, a pH of 5, and absence of protein, erythrocytes and leucocytes. Renal sonography showed a huge pelvic mass extending to the upper part of the abdomen, 20×10 cm in size, and with liquid fillings within the mass. A computed tomography (CT) of the abdomen revealed a heterogeneous mass with soft tissue components in its lower part, extending to the perineum and causing significant mass effect on the surrounding structures (Fig. 1).