Vascularite à anticorps anti-membrane basale glomérulaire secondaire au Covid-19 : observation inédite !

Introduction

La maladie des anticorps anti-membrane basale glomérulaire (Ac anti-MBG) est une affection auto-immune médiée par des anticorps dirigés conte la MBG et alvéolaire définissant le syndrome pneumo rénal. Plusieurs facteurs environnementaux ont été incriminés dans la genèse de cette maladie notamment les infections virales des voies respiratoires. Nous rapportons le cas d’une maladie à Ac anti-MBG survenue suite à une infection par le Sars Cov2.

Observation

Patiente âgée de 56 ans, non tabagique, suivie pour une insuffisance antéhypophysaire sous traitement substitutif, qui a consulté aux urgences pour fièvre, rhinorrhée, toux, diarrhée avec douleurs abdominales diffuses et oligurie évoluant depuis 02 semaines. L’examen objectivait une fièvre à 39 °C, un état hémodynamique stable, une pression artérielle à 11/06 mmHg et une tachycardie à 110 bpm. La saturation pulsée de l’oxygène était à 95 % à l’air ambiant. Elle présentait des œdèmes des 2 membres inférieurs de type rénal. Les bandelettes urinaires ont objectivé une hématurie à 2 croix associée à une protéinurie à 2 croix. Le reste de l’examen était sans anomalies. La patiente présentait à la biologie une créatinine à 1295 μmol/L, une protéinurie de 24 heures à 1 g, un syndrome inflammatoire et une anémie hypochrome microcytaire. L’échographie rénale a objectivé des reins de taille normale avec une bonne différenciation cortico-médullaire.

Devant les signes respiratoires et la fièvre, une infection par le Sars-Cov2, fortement suspectée vue le contexte pandémique, était confirmée par un test PCR. Par ailleurs, devant l’insuffisance rénale aiguë, la patiente a eu des séances d’hémodialyse et une ponction biopsie rénale avec étude en immunofluorescence montrant une glomérulonéphrite extra-capillaire associée à des dépôts linéaires d’IgG et une nécrose fibrinoïde. Les étiologies toxiques, iatrogènes, infectieuses (hormis la Covid) et néoplasiques étaient éliminées. Devant ce tableau clinico-biologique, histologique et la positivité du bilan immunologique montrant des Ac anti-MBG positif à 3+ des anticorps antimyéloperoxydase positif à 2+ associés à une cryoglobulinémie positive, le diagnostic de maladie des Ac anti-MBG était retenu. Un complément d’exploration par fibroscopie bronchique avec lavage broncho-alvéolaire était en faveur d’une hémorragie intra-alvéolaire avec un score de Golde à 102. La patiente a reçu donc des boli de méthylprednisolone à la dose de 800 mg/j durant 3 jours, relayés par une corticothérapie orale à la dose de 1 mg/kg/j associés aux échanges plasmatiques et à l’hémodialyse. Après guérison de l’infection COVID-19, des cures de cyclophosphamide ont été initiées. L’évolution sur le plan rénal était marquée par le passage au stade terminal de l’insuffisance rénale chronique nécessitant l’épuration extrarénale régulière.

Conclusion

Plusieurs cas de vascularite post infection Covid-19 ont été rapportés dans la littérature. Les mécanismes physiopathologiques responsables de cette association restent jusque-là mal élucidés. Ainsi, devant toute anomalie du sédiment urinaire et/ou de la fonction rénale survenant au cours ou au décours de la maladie Covid-19, une vascularite doit impérativement être évoquée afin d’instaurer un traitement adapté le plutôt possible, seul garant d’un meilleur pronostic.

[Renal involvement in sarcoidosis: Prognostic and predictive factors]

INTRODUCTION

Sarcoidosis is a systemic granulomatous disease that primarily affects the respiratory system and lymphatic vessels. Renal involvement is rare, poorly studied and found in less than 10% of cases. The objective of our study was to identify factors of poor renal prognosis and predictive factors of renal involvement during sarcoidosis.

METHODS

It's a retrospective study including patients hospitalized in our department for sarcoidosis with renal involvement over a period of 40 years. To study renal survival, we identified two groups of patients with renal manifestations of sarcoidosis by following their evolution: group A (n=26) represents those with renal remission or deterioration of renal function but without progression to end-stage renal disease and group B (n=8) those with progression to end-stage renal disease. To detect the predictive factors of end-stage renal disease in patients with sarcoidosis, we compared the clinical and paraclinical characteristics of our patients (group 1) to those of 44 patients with sarcoidosis without renal impairment followed in our department during the same period (group 2).

RESULTS

Renal involvement was observed in 34 patients hospitalized for sarcoidosis (43.6%). There were 28 women and 6 men with a sex ratio of 0,21. The mean age at diagnosis of sarcoidosis was 47.1 years. The median time from sarcoidosis diagnosis to renal disease was 2 months (range 1-72). Tubulointerstitial nephropathy was the most frequent renal manifestation observed in 24 patients (70.6%). Hypercalcemia and hypercalciuria were found in 52.9% and 46.4% respectively. Renal failure was noted in 25 patients (73.5%). Corticosteroid therapy was initiated in 33 patients (97%) associated with immunosuppressive therapy in 3 cases. Predictive factors of end-stage renal disease were advanced age at diagnosis of nephropathy (P=0.007), comorbidities (P=0.002), multi-organ involvement (P=0.041), initial renal failure (P=0.013), interstitial fibrosis (P=0.006) and renal granulomas (P=0.007). Predictive factors of renal impairment during sarcoidosis were multi-organ involvement, inflammatory syndrome and hypercalcemia.

CONCLUSION

Renal envolvement, although rare during sarcoidosis, can influence the prognosis hence the great interest of its early detection to prevent progression to end-stage renal failure.

MO707MICROBIOLOGY, CLINICAL SPECTRUM AND OUTCOME OF INFECTIOUS PERITONITIS IN PATIENTS ON AUTOMATED PERITONEAL DIALYSIS

Background and Aims

Automated peritoneal dialysis (APD) is a renal replacement therapy that offers patients various advantages such autonomy and comfort. Peritoneal dialysis-related infectious peritonitis (IP) is the most common and severe complication of APD. It is the main cause of technique failure and transfer to hemodialysis and can even be life-threatening. Given the seriousness of this complication, it is necessary to establish preventive strategies and adapt the therapeutic management.The aim of this study was to determine the microbiological and clinical profile of IP, to specify its causes its rate and outcome in patients treated by DPA at the unit of Charles Nicolle hospital in Tunis between January 2000 and December 2018.

Method

We conducted a single-center descriptive retrospective study in the peritoneal dialysis (PD) unit of Charles Nicolle Hospital in Tunis. We identified the episodes of IP occurring in patients treated with APD during the period from January 2000 to December 2018. We studied the clinical, biological and evolutionary aspects of IP.

Results

APD was used in 85% of patients treated at our PD unit during the study period. 322 episodes of IP occurred in 183 patients, that was an IP rate of 0.1 episodes/patient-year. 58% of patients treated with DPA have not presented IP. The mean age of the patients who presented PI was 43 years +/- 15(Extreme: 17-77) with a sex-ratio of 1.23. 74% of patients had a professional activity. 98% of patients had co-morbidities dominated by hypertension (88%), dyslipidemia(73%) and diabetes(16%) with a median Charlson score of 2[2-3] (Extremes: 2-9). Their average Body Mass Index was 24kg/m2+/-5. 33% of the patients were smokers. The average training duration before starting APD was 13days+/-5. The IP were evenly distributed according to seasons (27% occurred in autumn, 26% in spring, 25% in summer and 22% in winter). IP were: a 1st episode in 55% of cases, a new episode in 30% of cases, a relapse in 10% of cases, a recidivism in 3% of cases and a recurrence in 2% of cases. Fever was present in 34% of patients, abdominal pain in 75% of them. The dialysate was cloudy in 98% of cases. The median number of leukocytes in the PD fluid was 380/mm3(Range: 15-8000)with a mean% of neutrophils of 73%+/- 27. Dialysate culture was positive in 60% of cases, negative in 38% of cases and contaminated in 2% of cases. Among the positive cultures, only one was fungal (Candida albicans). Bacterial IP were distributed as follows: 64% Cocci Gram+ dominated by Staphylococcus aureus (48%), 34% Bacillus Gram- (mainly Klebsiella pneumoniae (21%) and Pseudomonas (21%)), 2 cases of Bacillus Gram+ (Corynebacterium afermentans and Lactobacillus) and 2 cases of polymicrobial culture (Cocci Gram+ and Bacillus Gram-).IP was of unknown cause in 48% of cases, related to an asepsis lack in 19% of cases, the orifice infection in 18% of cases and tunnelitis in 2% of cases. The other causes were essentially endogenous. Probabilistic antibiotic therapy was effective in 34% of cases. An adaptation according to the microbiological results was carried out in 19% of cases. Hospitalization was required in 10% of patients. 20% of peritonitis was refractory. Catheter ablation was performed in 14% of patients.IP caused the death of 8 patients and represented 37% of the causes of transfer to hemodialysis.

Conclusion

IPs are a turning point for the survival of the patient and the technique. Knowing the microbiological profile of these infections will make therapeutic interventions precocious and effective in order to preserve the prognosis of patients in APD at the short and long term.

[Successful treatment with paclitaxel of a visceral relapse of post-transplant Kaposi's sarcoma]

We report the observation of a patient who presented with post-transplant Kaposi's sarcoma after a delay of eight months with a dual cutaneous and palatal localisation. The reduction in immunosuppressive treatment and the introduction of Rapamune® allowed good clinical progress initially with regression of the skin lesions. He subsequently presented later a skin relapse with visceral localisation. Chemotherapy was conducted based on weekly paclitaxel infusions allowing partial remission and maintenance of renal graft function with good clinical tolerance.

Atypical hemolytic uremic syndrome: A monocentric adult Tunisian study and review of literature

Atypical hemolytic uremic syndrome (aHUS) is characterized by microvascular thrombosis resulting in thrombocytopenia, hemolytic anemia, and multiorgan dysfunction. It is associated with genetic or acquired disorders of regulatory components of the complement system. For our study, we collected data from 16 patients diagnosed with aHUS between January 2010 and January 2014. The mean age was 33.6 years. The female-to-male ratio was 3. The median follow-up duration was 27 ± 3.5 months. The most common clinical presentation was hypertension. Renal involvement was noted in all cases. Ten patients had extrarenal manifestations. Semi-quantitative dysfunction of the alternative pathway of complement was found in all cases. A genetic study was not available for our patients. During the acute stage, all patients received plasma therapy, and among them, seven required dialysis and five were still on dialysis at the time of discharge. One patient underwent renal transplantation. None of our patients received eculizumab perfusion. The renal survival was inversely correlated to young age (<30 years) (P = 0.001), presence of anti-factor H antibodies (P = 0.003) and serum creatinine at diagnosis >5 mg/dL (P = 0.02). Mortality rate was significantly correlated to young age (<30 years old) (P = 0.01). Collecting multicentric data on adult patients with aHUS will enable better characterization of the spectrum of adult aHUS in our country and the evaluation of current treatments and different outcomes.