[Patterns of nephrology referral and predialysis management of patients with chronic kidney disease]. / Suivi néphrologique et niveau de prise en charge des patients en insuffisance rénale terminale.

INTRODUCTION: Numerous studies showed that late referral (LR) to a nephrologist of patients with chronic kidney disease stated by a simple quantitative criterium (initiation of renal replacement therapy (RRT) within 3 or 4 months of referral to a nephrologist, independantly from the quality of care) is associated with worse survival rate, limited to the first 3 months following the initiation of RRT. We wanted to test a criterium of LR definition supposing a more important "dose of nephrological care", to try to understand the reasons of this early death. METHODS: One hundred and thirty-eight patients receiving their first RRT in 1999 and 2000 in Valenciennes (France) were enrolled in this study. Two LR definitions were used: a qualitative criterium C1 (whether the patient was under an uninterrumpted nephrological pre-dialysis care - independantly from the date of the nephrological referral - or not) and a more simple quantitative criterium C2 (initiation of RRT within 3 months of referral to a nephrologist). Comorbidity was assessed by Charlson's score. The analysis concerned the respective influence of C1 and C2 on the clinical and biological effects of chronical azotemia, on the circumstances at first RRT (emergency first dialysis, pulmonary edema, type of vascular access), and on survival rates (Kaplan-Meier's analysis). RESULTS: LR rates are 23% according to C1 and 20% according to C2. Comorbidity is similar in the different groups. Whatever the definition criterium, LR is associated to a lower hemoglobin and albumin, a more severe acidosis, a longer duration of first hospitalization, and higher rate of emergency first dialysis and use of central temporary catheter. The survival rates at 2 years following the first RRT of lately referred patients are 53% according to C1 (vs 86% for early referred patients, P<0,001) and 56% according to C2 (vs 84%, P<0,05). For both, early death (within the first 3 months) explained the observed differences of survival rates. CONCLUSION: In this study, early death of lately referred patients seems to be independant from the criterium of definition of LR. Elements of explanation are suggested, and can lead to further prospective studies.

Tubulointerstitial nephritis and Fanconi syndrome in primary biliary cirrhosis.

Primary biliary cirrhosis is a chronic cholestatic liver disease of unknown cause that predominantly affects middle-aged women. Distal tubular acidosis is the main renal complication of primary biliary cirrhosis. Tubulointerstitial nephritis and Fanconi syndrome have been reported more rarely. We report on 2 patients with primary biliary cirrhosis who presented with tubulointerstitial nephritis and Fanconi syndrome and review similar cases published previously. Serum from 1 patient exerted an inhibitory effect on pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, 2 mitochondrial enzymes that are the main targets of antimitochondrial antibodies in primary biliary cirrhosis. Antimitochondrial antibodies may have a role in the genesis of tubulointerstitial nephritis and Fanconi syndrome, 2 typical renal features of mitochondrial cytopathies. Tubulointerstitial nephritis and Fanconi syndrome have to be added to the spectrum of renal diseases associated with primary biliary cirrhosis.

Efficiency of curative and prophylactic treatment with rituximab in ADAMTS13-deficient thrombotic thrombocytopenic purpura: a study of 11 cases.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease that occurs mainly in young adults. Acquired cases are usually a result of antibodies directed against ADAMTS13 (a disintegrin-like and metalloprotease [reprolysin type] with thrombospondin type 1 motif 13), a protease that cleaves the von Willebrand factor multimers. Prognosis has been improved by plasma therapy, but some acute severe forms are refractory to this treatment and achieving a sustained remission is still a challenge in chronic relapsing forms. We therefore conducted a multicentric open-label prospective trial to test the efficacy of rituximab, an anti-B-cell monoclonal antibody, as a curative and prophylactic treatment in patients with TTP as a result of anti-ADAMTS13 antibodies. Six patients were included during an acute refractory TTP episode. Five patients with severe relapsing TTP and persistent anti-ADAMTS13 antibodies were prophylactically treated during remission. All patients received 4 weekly infusions of rituximab. The target of treatment was to restore a significant ADAMTS13 plasma activity (> 10%). Treatment with rituximab led to clinical remission in all cases of acute refractory TTP. In all patients, anti-ADAMTS13 antibodies disappeared, and a significant (18%-75%) plasma ADAMTS13 activity was detected following treatment. Tolerance of rituximab was good. Rituximab is a promising first-line immunosuppressive treatment in patients with acute refractory and severe relapsing TTP related to anti-ADAMTS13 antibodies.