[Significance of the urine strip test in case of stunted growth]

Observation of stunted growth in children usually leads the general practitioner to refer the patient to endocrinologists or gastroenterologists. In most cases, after a complementary check-up, the diagnosis is made and treatment is initiated. However, certain cases remain undiagnosed, particularly renal etiologies, such as proximal tubulopathy. The urine strip test at the initial check-up would be an easy and inexpensive test to avoid delayed diagnosis. The aim of the present paper is to increase general physicians' and pediatricians' awareness of the significance of questioning the parents and using the urine strip test for any child presenting stunted growth. We report a patient case of a 20-month-old child admitted to the emergency department for severe dehydration. He had displayed stunted growth since the age of 5 months and showed a negative etiologic check-up at 9 months of age. Clinical examination at admission confirmed stunted growth with loss of 2 standard deviations and signs of dehydration with persistent diuresis. Skin paleness, ash-blond hair, and signs of rickets were also observed and the urine strip test showed positive pads for glycosuria and proteinuria. Polyuria and polydipsia were also revealed following parents' questioning, suggesting proximal tubulopathy (Fanconi syndrome). Association of stunted growth, rickets, polyuria and polydipsia, glycosuria (without ketonuria and normal glycemia), and proteinuria suggest nephropathic cystinosis. Ophthalmic examination showed cystine deposits in the cornea. The semiotic diagnosis of nephropathic cystinosis was confirmed by leukocyte cystine concentrations and genetic investigations. This case report clearly illustrates the significance of the urine strip test to easily and quickly concentrate the diagnosis of stunted growth on a renal etiology (glycosuria, proteinuria), especially on proximal tubulopathy for which the most frequent cause is nephropathic cystinosis. Specificity of nephropathic cystinosis treatment is that the age of treatment initiation is crucial and determinant for the prognosis of the disease and the onset of final stage renal failure. Therefore, the urine strip test should be included in the systematic check-up of stunted growth to identify any renal etiology.

Cardiac troponin-I on diagnosis predicts early death and refractoriness in acquired thrombotic thrombocytopenic purpura. Experience of the French Thrombotic Microangiopathies Reference Center

BACKGROUND

Cardiac involvement is a major cause of mortality in patients with thrombotic thrombocytopenic purpura (TTP). However, diagnosis remains underestimated and delayed, owing to subclinical injuries. Cardiac troponin-I measurement (cTnI) on admission could improve the early diagnosis of cardiac involvement and have prognostic value.

OBJECTIVES

To assess the predictive value of cTnI in patients with TTP for death or refractoriness.

PATIENTS/METHODS

The study involved a prospective cohort of adult TTP patients with acquired severe ADAMTS-13 deficiency (< 10%) and included in the registry of the French Reference Center for Thrombotic Microangiopathies. Centralized cTnI measurements were performed on frozen serum on admission.

RESULTS

Between January 2003 and December 2011, 133 patients with TTP (mean age, 48 ± 17 years) had available cTnI measurements on admission. Thirty-two patients (24%) had clinical and/or electrocardiogram features. Nineteen (14.3%) had cardiac symptoms, mainly congestive heart failure and myocardial infarction. Electrocardiogram changes, mainly repolarization disorders, were present in 13 cases. An increased cTnI level (> 0.1 μg L(-1) ) was present in 78 patients (59%), of whom 46 (59%) had no clinical cardiac involvement. The main outcomes were death (25%) and refractoriness (17%). Age (P = 0.02) and cTnI level (P = 0.002) showed the greatest impact on survival. A cTnI level of > 0.25 μg L(-1) was the only independent factor in predicting death (odds ratio [OR] 2.87; 95% confidence interval [CI] 1.13-7.22; P = 0.024) and/or refractoriness (OR 3.03; 95% CI 1.27-7.3; P = 0.01).

CONCLUSIONS

A CTnI level of > 0.25 μg L(-1) at presentation in patients with TTP appears to be an independent factor associated with a three-fold increase in the risk of death or refractoriness. Therefore, cTnI level should be considered as a prognostic indicator in patients diagnosed with TTP.

Treatment of acute decompensation of maple syrup urine disease in adult patients with a new parenteral amino-acid mixture

BACKGROUND

Acute decompensation of maple syrup urine disease (MSUD) is usually treated by enteral feeding with an amino-acid mixture without leucine (Leu), valine or isoleucine. However, its administration is ineffective in cases of gastric intolerance and some adult patients refuse enteral feeding via a nasogastric tube. We developed a new parenteral amino-acid mixture for patients with MSUD.

METHODS

Seventeen decompensation episodes in four adult patients with MSUD treated with a parenteral amino-acid mixture (group P) were compared to 18 previous episodes in the same patients treated by enteral feeding (group E).

RESULTS

The mean Leu concentration at presentation was similar in the groups P and E (1196.9 μmol/L and 1212.2 μmol/L, respectively). The mean decrease in the Leu concentration during the first 3 days of hospitalisation was significantly higher in group P than group E (p = 0.0026); there were no side effects. The mean duration of hospitalisation was similar (4 vs. 4.5 days, p = NS). No patient in group P deteriorated whereas one patient in group E required dialysis.

CONCLUSION

This new parenteral amino-acid mixture is safe and allows efficient Leu concentration decrease during acute MSUD decompensation episodes in adults. Its use avoids the need for nasogastric tube insertion.

[Clinical case of the month. Idiopathic mediastinal fibrosis]

Fibrosing mediastinitis is a rare condition characterized by an excessive growth of dense fibrous tissue within the mediastinum. The etiology of the disease is most often a fungal infection and may in some cases be idiopathic. We present the case of a patient with chronic obstructive pulmonary disease (COPD) suffering from fibrosing mediastinitis of undetermined origin and in whom the diagnosis was established by histopathological analysis after mediastinoscopy.

Interstitial fibrosis evolution on early sequential screening renal allograft biopsies using quantitative image analysis

Screening renal biopsies (RB) may assess early changes of interstitial fibrosis (IF) after transplantation. The aim of this study was to quantify IF by automatic color image analysis on sequential RB. We analyzed RB performed at day (D) 0, month (M) 3 and M12 from 140 renal transplant recipients with a program of color segmentation imaging. The mean IF score was 19 ± 9% at D0, 27 ± 11% at M3 and 32 ± 11% at M12 with a 8% progression during the first 3 months and 5% between M3 and M12. IF at M3 was correlated with estimated glomerular rate (eGFR) at M3, 12 and 24 (p < 0.02) and IF at M12 with eGFR at M12 and 48 (p < 0.05). Furthermore, IF evolution between D0 and M3 (ΔIFM3-D0) was correlated with eGFR at M24, 36 and 48 (p < 0.03). IF at M12 was significantly associated with male donor gender and tacrolimus dose (p = 0.03). ΔIFM3-D0 was significantly associated with male donor gender, acute rejection episodes (p = 0.04) and diabetes mellitus (p = 0.02). Thus, significant IF is already present before transplantation. IF evolution is more important during the first 3 months and has some predictive ability for change in GFR. Intervention to decrease IF should be applied early, i.e. before 3 months, after transplantation.

[Fabry disease and cystinosis, two lysosomal diseases: similarities and differences]

Fabry disease and cystinosis are both lysosomal diseases. Some clinical features (such as renal and corneal involvement) are shared by both diseases whereas many other features are different (mode of inheritance, rate of progression, mechanism of lysosomal storage, therapeutic modalities etc.). Intermediary mechanisms that lead from lysosomal overload to lesions and disease are still incompletely understood.

Interstitial fibrosis quantification in renal transplant recipients randomized to continue cyclosporine or convert to sirolimus

Conversion from cyclosporine (CsA) to sirolimus at week 12 after kidney transplantation is associated with a significant improvement in renal function. The aim of this analysis was to investigate the effect of this conversion on interstitial fibrosis (IF), a hallmark of chronic allograft injury, in patients taking part in the CONCEPT trial. This multicenter, prospective, trial included 193 renal recipients randomized at week 12 to switch from CsA to sirolimus or to continue CsA, with mycophenolate mofetil. Routine biopsy with automated, quantified assessment of IF by a program of color segmentation was performed at 1 year in 121 patients. At 1 year, renal function was significantly improved in the conversion group as assessed by estimated GFR (MDRD) and measured GFR. Biopsy results, however, showed no between-group difference in percentage of IF. Calculated GFR at 1 year was significantly associated with the percentage of IF (p = 0.004, R(2)= 0.07). By multivariate analysis diabetic patients had more fibrosis than non-diabetic patients. In conclusion, although kidney transplant patients converted from CsA to sirolimus showed significant improvement in renal function, we found no difference of IF on 1-year biopsies.

Lithiases médicamenteuses

Drug-induced renal calculi represent 1-2% of all renal calculi. They include two categories: those resulting from the urinary crystallisation of a highly excreted, poorly soluble drug or metabolite, and those due to the metabolic effects of a drug. Indinavir, used in HIV-infected patients, sulfonamides, especially sulfadiazine, and triamterene, which is less prescribed today, are the most frequent. Besides these drugs, about twenty other molecules, among them silicate-containing drugs and some antibiotics have been reported in patients receiving high doses or long-term treatments. Calculi analysis by physical methods such as infrared spectroscopy or x-ray diffraction can demonstrate the presence of the drug or its metabolites inside the calculi. In those calculi due to the metabolic effects of a drug, diagnosis relies on both stone analysis and clinical inquiry. Incidence of such calculi is probably underestimated, especially those due to calcium/vitamin D supplements or carbonic anhydrase inhibitors. Drug-induced calculi occur more often during high-dose or long term treatments, but there are also patient-related risk factors in relation to urine pH, urine output and other parameters, which can provide a basis for preventive treatment of such calculi. A better knowledge of these lithogenic complications of treatments and of solubility characteristics of drugs should reduce the incidence of drug-induced nephrolithiasis, especially in patients with identified risk factors.

[Pheochromocytoma: 25 years of experience. Report of 199 cases]

The methods for diagnosing pheochromocytoma have progressed in 25 years, so changing the clinical, biological and tumoral presentations. The authors compare the features of 199 patients with pheochromocytoma operated between 1975 and 2001 by quartiles. The frequency and known duration of hypertension, plasma adrenaline, the tumour size and proportion of cases which were malignant from the outset, have decreased over the observation period (p < 0.01). The average age and proportion of familial cases or associated with diabetes or those of asymptomatic patients (with incidentaloma), has not changed significantly. The pheochromocytoma were adrenal (104 right, 60 left, 12 bilateral) or ectopic (23) and 13 were malignant from the outset. Over a median 5 year follow-up, 35 pheochromocytomas recurred either in the benign or malignant forms. Recurrences of tumours of the right adrenal were more common than those of the left adrenal gland (p = 0.03). In conclusion, pheochromocytomas are diagnosed earlier, at a stage when the tumours are smaller and less secreting. The higher incidence and recurrence rate of right adrenal pheochromocytoma remain unexplained.

Autoimmune pancreatitis mimicking cancer of the head of pancreas: report of two cases

Autoimmune pancreatitis has been characterised in 1995, but only a few cases have been published since then, most of them from Japan. This report describes the cases of two Belgian male patients who presented with isolated obstructive jaundice. Radiological imaging studies were highly suggestive of carcinoma of the head of pancreas and both patients underwent uneventful cephalic pancreaticoduodenectomy with portal vein resection. Pathological analysis of the removed tissues suggested an autoimmune process in both cases. Both patients had hyper-gammaglobulinemia and antinuclear antibodies, but failed to show evidence of any other autoimmune disease or cause of chronic pancreatitis. In both cases final diagnosis was autoimmune pancreatitis. Preoperative clinical suspicion of this diagnosis is mandatory and may avoid unnecessary surgery in future cases.

[Clinical case of the month. Von Hippel-Lindau disease]

VHL disease is a rare genetical disease with a poor long-term prognosis. Clinical features include retineous angiomas, CNS hemangioblastomas, pheochromocytomas and renal cysts. Renal cysts are bilateral and frequently lead to malignant transformation. Surgical treatment of renal cysts is preferably delayed until a minimum of 3 cm diameter has been reached. Treatment has to be as conservative as possible, knowing that uni- or bilateral nephrectomy often has to be carried out later.