Organ Transplantation in Hereditary Fibrinogen A α-Chain Amyloidosis: A Case Series of French Patients.

RATIONALE & OBJECTIVE: Fibrinogen A α-chain amyloidosis (AFib amyloidosis) is a form of amyloidosis resulting from mutations in the fibrinogen A α-chain gene (FGA), causing progressive kidney disease leading to kidney failure. Treatment may include kidney transplantation (KT) or liver-kidney transplantation (LKT), but it is not clear what factors should guide this decision. The aim of this study was to characterize the natural history and long-term outcomes of this disease, with and without organ transplantation, among patients with AFib amyloidosis and various FGA variants. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 32 patients with AFib amyloidosis diagnosed by genetic testing in France between 1983 and 2014, with a median follow-up of 93 (range, 4-192) months, were included. RESULTS: Median age at diagnosis was 51.5 (range, 12-77) years. Clinical presentation consisted of proteinuria (93%), hypertension (83%), and kidney failure (68%). Manifestations of kidney disease appeared on average at age 57 (range, 36-77) years in patients with the E526V variant, at age 45 (range, 12-59) years in those with the R554L variant (P<0.001), and at age 24.5 (range, 12-31) years in those with frameshift variants (P<0.001). KT was performed in 15 patients and LKT was performed in 4. In KT patients with the E526V variant, recurrence of AFib amyloidosis in the kidney graft was less common than with a non-E526V (R554L or frameshift) variant (22% vs 83%; P=0.03) and led to graft loss less frequently (33% vs 100%). Amyloid recurrence was not observed in patients after LKT. LIMITATIONS: Analyses were based on clinically available historical data. Small number of patients with non-E526V and frameshift variants. CONCLUSIONS: Our study suggests phenotypic variability in the natural history of AFib amyloidosis, depending on the FGA mutation type. KT appears to be a viable option for patients with the most common E526V variant, whereas LKT may be a preferred option for patients with frameshift variants.

[Hypouricemia, an old subject and new concepts]. / Hypo-uricémie, un vieux sujet et de nouveaux concepts.

DEFINITION OF HYPOURICEMIA: Hypouricemia (serum uric acid less than 120 micro mol/l) is a biological abnormality often discovered accidentally and with a low prevalence depending on its permanent or transitory nature ranging from 0.15 to 3.38%. NEW PHYSIOLOGICAL CONCEPTS OF ITS PATHOGENESIS: Recently, our knowledge of the physiopathological mechanisms of hypouricemia has been emphasized by the identification of three systems of renal and extra-renal uric acid transport: a Cl/urate (URAT1) transporter, a multispecific organic anion transporter (OAT) and a urate transporter/channel. ETIOLOGY AND COMPLICATIONS OF HYPOURICEMIA: Through questioning, drugs and toxics (allopurinol.) are generally rapidly recognized as responsible for half of the hypouricemia encountered. It can be concomitant to a known disease: severe liver disease, neoplasia, diabetes, AIDS, syndrome of inappropriate antidiuretic hormone secretion. Hypouricemia can also be isolated and justifies the measurement of uric acid clearance, the normality or reduction of which orients towards a deficiency in xanthine-oxydase, the increase in which suggests an abnormality in uric acid transport in the proximal tubule (Fanconi syndrome, primary hereditary anomaly of tubular uric acid transport). Hypouricemia does not appear to expose the patient to any danger, but the onset of nephrolithiasis or acute renal failure secondary to the combination of severe hypouricemia and oxidant stress is always possible.

[Upper mesenteric venous thrombosis revealing familial resistance to activated protein C]. / Thrombose veineuse mésentérique supérieure révélant une résistance à la protéine C activée familiale.

INTRODUCTION: Mesenteric venous thrombosis is a rare disease but potentially severe because of the prognosis of intestinal infarction with high mortality rate (60%). OBSERVATION: We report the case of a 55 year-old man who presented with an upper mesenteric venous thrombosis related to a familial resistance to C reactive protein through factor V Leiden mutation. COMMENTS: The discovery of a mesenteric venous thrombosis requires aetiological research that is usually multifactorial. Among the most frequent genetic coagulation abnormalities observed resistance to C reactive protein due to G202110A prothrombin gene mutation is the most common. Although factor V Leiden mutation is less frequent, it requires anticoagulation therapy for life in the case of the appearance of a thrombosis.

[Sarcoidosis of the kidney and skin without lung involvement]. / Sarcoïdose rénale et cutanée sans atteinte pulmonaire.

We report the case of a patient with predominantly renal sarcoidosis. Renal failure responded well to systemic corticosteroid therapy. The clinical presentation was particular, notably the absence of lung involvement and the presence of cutaneous lymphedema.

Encrusted pyelitis of native kidneys.

This study reports the first four cases of encrusted pyelitis involving native kidneys. The clinical features, management, and outcome of these patients were analyzed. Predisposing factors were underlying urologic disease and/or urologic manipulations, debilitating diseases, hospitalization, and prolonged antibiotic therapies. Presenting symptoms were renal failure in three patients with ureteroileal urinary diversion and manifestations of cystitis in one patient. Computed tomography scan of the urinary tract was critical for diagnosis. Presence of struvite was demonstrated by crystalluria and infrared spectrophotometry analysis of the encrusted material. Corynebacterium urealyticum urinary infection was identified in one case. Surgery (one patient) and palliative ureteral diversion (one patient), respectively, led to death and end-stage renal failure. Successful dissolution of encrusted pyelitis was obtained in two patients treated with intravenous vancomycin and local acidification of the renal collecting system. Clinical observation shows that encrusted pyelitis is a threatening disorder that destroys the native kidneys and may lead to end-stage renal failure. Successful treatment of the disease by chemolysis and antibiotics depends on correct and early diagnosis. Diagnosis required recognition of the predisposing factors, computed tomography imaging of the urinary tract, crystalluria, and identification of urea-splitting bacteria with prolonged culture on selective medium.