Renal transplantation in 4 patients with methylmalonic aciduria: a cell therapy for metabolic disease.

INTRODUCTION: Patients with methylmalonic acidemia (MMA) may develop many complications despite medical treatment, in particular, severe central nervous system damage and chronic kidney disease (CKD). A kidney transplant may partially correct the metabolic dysfunctions. Liver, kidney and combined liver-kidney transplantations have been advocated but no guidelines are available to identify the most suitable organ to transplant. PATIENTS AND METHODS: Four patients with MMA (mut° phenotype) received a kidney graft because of repeated metabolic decompensations, with progression to CKD in 3 patients (end-stage kidney disease in two patients and CKD stage III in one patient with an estimated glomerular filtration rate [eGFR] of 40ml/min/1.73m(2)) but normal renal function in one (eGFR of 93ml/min/1.73m(2)) before transplantation. RESULTS: The medium age at transplantation was 7.9y (5-10.2) and the median follow-up was 2.8years (1.8-4.6). Renal transplantation improved the relevant metabolic parameters in 4/4 patients and renal function in the patients with CKD. Plasma and urinary MMA levels immediately decreased and remained normal or subnormal (mean values of plasma MMA before transplantation 1530µmol/L versus 240µmol/L after transplantation, and mean values of urine MMA before transplantation 4700mmol/mol creatinine versus 2300mmol/mol creatinine after transplantation). No further acute metabolic decompensation was observed and protein-intake was increased from 0.60 to 0.83g/Kg/day. One patient transplanted at age 9.7years developed a hepatoblastoma at age 11years with subsequent neurological complications and eventually died. The three other patients are alive. Two of them remained neurologically stable. The 3rd patient who displayed choreoathetosis transiently improved his neurological condition immediately after transplantation and then remained stable. CONCLUSION: Kidney transplantation represents an interesting alternative therapeutic option in methylmalonic aciduria, for renal complications but also as a "cellular therapy" that may significantly reduce metabolic decompensations and hospitalizations. However, further neurological impairment remains possible.

[Unusual presentation of rib malformation]. / Présentation inhabituelle d'une malformation costale.

Rib malformation and anatomical variations are not well known and are still often underdiagnosed. Usually, rib malformations are fortuitously discovered. We describe here the case of a girl, 4 years and 4 months old, who presented at the emergency unit for fever and an anterior tumefaction of the ribcage, without any other symptoms. She was eupneic with a normal pulmonary auscultation and viral tonsillitis with a negative streptococcus test. The thoracic tumefaction was parasternal, painless, and fixed and measured approximately 2.5 × 2cm. Ultrasound findings consisted of a duplicated and hypoechogenic hypertrophy of the sterno-costal cartilage of the 4th left rib. Magnetic resonance imaging (MRI) confirmed the diagnosis of chondral bifidity of the sterno-costal junction of the 4th left rib. Fever, due to the viral tonsillitis, disappeared after 4 days. Rib malformations are rare, often anterior, unilateral, and preferentially located on the 3rd or the 4th rib. The main malformative rib lesions are bifid ribs, rib spurs, and widened ribs. Very rarely, they can be associated with Gorlin-Goltz syndrome or with other malformations such as VATER complex. The main differential diagnoses of these rib malformations are traumatic, tumoral, and infectious etiologies. In case of tumoral diseases, the topography of the lesion focuses the etiologic diagnosis: whereas an anterior and cartilaginous lesion is always benign, a lateral or posterior lesion can be an Ewing sarcoma. Rib malformation investigation consists in meticulous questioning, a complete clinical examination looking for any associated anomaly, completed by basic imaging explorations such as plain thoracic radiography focused on the ribcage and ultrasound. Finally, complementary computerized tomography or preferably MRI, depending on the anatomic location of the lesion, confirms the final diagnosis, as presented in our case report, and removes any uncertainty.

Long-term outcome in methylmalonic aciduria: a series of 30 French patients.

OBJECTIVE: To better delineate the natural history of patients with methylmalonic aciduria (MMA). STUDY DESIGN: Thirty patients with vitamin-B12-unresponsive MMA (25 aged 1.5 to 22.0 years (y) at the end of the study and 5 who died during a metabolic crisis) were managed following standardized guidelines and studied retrospectively. The median follow-up was 8.3 y (range: 1.4-19.5). Patients were investigated with neuropsychological testing, brain MRIs, inulin clearances, biochemical and genetic studies. RESULTS: Fifteen patients had a neonatal onset. Thirteen patients (43%) had significant neurological impairment. Chronic renal disease (CRD) occurred in 14 patients (47%) with a median age of onset of 6.5 y (range 1.5-18.6). Renal function further deteriorated in 4 patients within a median period of 5.8 y (range 2-7.4). Of 25 patients investigated at the enzymatic level, 17 were classified mut(o), 3 mut- and 5 cblA. Mortality, number of acute decompensations (p=0.031), median MMA urinary excretion (p=0.006) and neurological impairment (p<0.0001) were higher in mut degrees patients compared to mut-/cblA patients. Concerning the CRD, no difference incidence was found although the onset of CRD occurred earlier in mut(o) patients and was more severe. CONCLUSIONS: Our study provides unique data concerning the progression of renal disease in MMA. Patients with mut(o) phenotype have a more severe phenotype and probably an earlier and more severe CRD than patients with mut-/cblA phenotype.

Liver hepatoblastoma and multiple OXPHOS deficiency in the follow-up of a patient with methylmalonic aciduria.

A boy who was diagnosed with methylmalonic aciduria (MMA) at the age of 10 days developed persistent hepatomegaly and raised transaminases from the age of 4 years. He was subsequently diagnosed with Leigh syndrome and required a kidney transplantation for end-stage renal failure. A massive hepatoblastoma led to his death by the age of 11 years. Methylmalonyl-CoA mutase activity was undetectable on both cultured skin fibroblasts and kidney biopsy and multiple respiratory chain deficiency was demonstrated in the kidney. Mitochondrial dysfunction and/or post-transplant immunosuppressive therapy should be considered as a possible cause of liver cancer in this patient.

[Ibuprofen in childhood: evidence-based review of efficacy and safety]. / Quel niveau de preuve de l'efficacité et de la sécurité de l'ibuprofène dans ses indications pédiatriques?

Ibuprofen is the non-steroidal anti-inflammatory drug most prescribed for the treatment of fever and moderate pain in childhood. Its analgesic and antipyretic efficacy is now well documented: at equal doses ibuprofen appears slightly more effective than acetaminophen in the treatment of fever and is equivalent for analgesia. However, adverse effects should be taken into account in the choice between ibuprofen and acetaminophen. Lot of studies (case reports, cohort studies, case-control studies and one multicenter double-blind randomized control trial) have reported ibuprofen adverse effects at therapeutics doses. These data suggest there is an increased risk of invasive group A streptococcal infection after chickenpox and of acute renal failure in case of hypovolemia after a treatment by ibuprofen. Gastroduodenal and hemorrhagic adverse events could also happen, but the causality with ibuprofen is not demonstrated. Therefore, ibuprofen is not recommended for the treatment of fever or moderate pain during chickenpox or during a disease with a risk of dehydration, until other pharmacoepidemiology studies more accurately quantify the risk of adverse events of ibuprofen in children.