The natural history of clinical operational tolerance after kidney transplantation through twenty-seven cases.

We report here on a European cohort of 27 kidney transplant recipients displaying operational tolerance, compared to two cohorts of matched kidney transplant recipients under immunosuppression and patients who stopped immunosuppressive drugs and presented with rejection. We report that a lower proportion of operationally tolerant patients received induction therapy (52% without induction therapy vs. 78.3%[p = 0.0455] and 96.7%[p = 0.0001], respectively), a difference likely due to the higher proportion (18.5%) of HLA matched recipients in the tolerant cohort. These patients were also significantly older at the time of transplantation (p = 0.0211) and immunosuppression withdrawal (p = 0.0002) than recipients who rejected their graft after weaning. Finally, these patients were at lower risk of infectious disease. Among the 27 patients defined as operationally tolerant at the time of inclusion, 19 still display stable graft function (mean 9 ± 4 years after transplantation) whereas 30% presented slow deterioration of graft function. Six of these patients tested positive for pre-graft anti-HLA antibodies. Biopsy histology studies revealed an active immunologically driven mechanism for half of them, associated with DSA in the absence of C4d. This study suggests that operational tolerance can persist as a robust phenomenon, although eventual graft loss does occur in some patients, particularly in the setting of donor-specific alloantibody.

[Acute renal failure and 2,8-dihydroxyadeninuria]. / Insuffisance rénale aiguë et 2,8-dihydroxyadéninurie.

We report the case of a 65 year old man, with a history of recurrent urolithiasis, who was referred for an acute renal failure. Investigations deny obstructive or glomerular involvement. 2,8-Dihydroxyadeninuria was diagnosed with the help of crystalluria. This rare metabolic disease is due to a deficiency of adenine phosphoribosyltransferase, a purine salvage enzyme. Allopurinol, a low purine diet and high fluid intake made possible the nearly entire regression of renal failure.

[Difficulties in diagnosing an aortic arch thrombus]. / Difficultés diagnostiques d'un thrombus de la crosse aortique.

INTRODUCTION: Thrombosis of the aortic arch is a rare and often underdiagnosed source of peripherical arterial embolic events. EXEGESIS: We report a case with a non-typical initial clinical presentation of polyarteritis nodosa. A mobile thrombus in the aortic arch was secondarily suspected when disseminated arterial embolism appeared. Transthoracic echocardiography failed twice to diagnosticate the source of embolism. The diagnosis was only performed with transesophageal echocardiography and confirmed by computed tomography and magnetic resonance imaging of the thoracic aorta. The thrombus completely disappeared after six months of oral anticoagulant therapy. CONCLUSION: Although rare, this diagnosis mustn't be disregarded in an etiologic view of recurrent and disseminated peripherical ischemic events (even clinically silent ones) under penalty of detrimental functional consequences due to a delayed diagnosis.

[Cutaneous atypical Mycobacterium infection with hematogenic dissemination]. / Mycobactériose atypique cutanée avec dissémination hématogène.

Non-tuberculous mycobacteria are ubiquitous non-pathogens except for subjects with deficient local or general defence systems. Nearly 80% of the cases observed in France occur in HIV+ patients. Lung, lymph node or skin infections usually simulate tuberculosis and diagnosis must be based on precise identification of the infectious strain. Recommended treatment of M. kansasii is now well established but protocols for other mycobacteria are still under evaluation. We observed a case presenting with persistent fever resistant to large spectrum antibiotics. This case occurred in a 75-year-old non-immunodepressed women who presented typical microcalcifications of the skin subsequent to blood stream dissemination.

[Chester-Erdheim's disease. A case]. / Maladie de Chester-Erdheim. Une observation.

We report the 32nd case of a multivisceral form of Erdheim-Chester disease. This exceptional pathology is a diffuse xanthogranulomatosis which comes within the scope of histiocytosis. The originality of this case is due to cerebral localizations and to the fact that some symptoms have been observed for a long time: diabetes insipidus, exophthalmos and stubborn intertrigo.