Therapeutic plasmapheresis in idiopathic membranous nephropathy anti-PLA2R-related: A case series.

Membranous nephropathy is the most common cause of nephrotic syndrome (NS) in non-diabetic adults; in 80% of patients it is idiopathic (PMN). PMN has an autoimmune pathogenesis, 70%-85% of patients have increased titer of antibodies to the podocyte membrane antigen PLA2R. The etiological, prognostic and predictive role of the Ab anti-PLA2R is demonstrated. Standard therapy consists in anti-CD20 monoclonal antibody rituximab (RTX) combined with steroids or immunosuppressants according to the risk of progressive loss of kidney function. The immunosuppressive therapies are potentially associated to severe adverse events that lead to protocol suspension. Given their pivotal pathogenetic role, serum clearance of anti-PLA2R with plasmapheresis could have a beneficial impact on NS, particularly in patients not requiring or tolerating standard therapies. In this series, we present three cases of PMN anti-PLA2R related treated with a RTX plus plasmapheresis approach and demonstrate its overall effective role on anti-PLA2R titer and clinical outcomes.

Impact of peritoneal catheter intramural design on dialysis discontinuation rate.

AIM: Catheter dislocation is an important cause of technique failure for peritoneal dialysis (PD). Aim of this study is to evaluate the effect of intramural trait configuration on this outcome. METHODS: We considered 240 swan neck, double-cuffed catheters positioned in adult patients in our Centre with mini-laparotomy technique partitioned, according with the intramural segment design, in a standard technique group (ST) (n. 199): oblique passage of the catheter through the rectus sheath in the craniocaudal direction, and in a modified technique group (MT) (n. 41): anterior fascia lanced 3 cm cranially to the deep cuff to let catheter out. The primary end-point was dialysis failure due to tip migration. Secondary end-points were any other causes of catheter removal. RESULTS: Incidence of catheter removal for non-responsive tip migration was 14.3% in MT and 6.1% in ST. Neither this difference nor the catheter survival rate for this outcome was statistically significant. PD interruption for refractory exit site/tunnel infection (ESI) was in favour of ST (4% ST, 35.7% MT; P < .01) whereas ESI catheter survival rate was only marginally significant (292.8 days in MT vs 743.6 in ST, P = .045). No other recorded cause of PD discontinuation was significantly different. CONCLUSION: Modified technique group is associated with a major ESI risk but, given the average survival, it seems to be due more to exit site management than to the specific surgical procedure. MT is not superior to ST to prevent catheter dislocation nevertheless, considering its simplicity and rapidity it can be deemed as first-choice option.

[Acute heart failure secondary to takotsubo cardiomyopathy in a patient on peritoneal dialysis with residual renal function loss]. / Insufficienza cardiaca acuta secondaria a cardiomiopatia Takotsubo in paziente in dialisi peritoneale con perdita della funzione renale residua.

Takotsubo cardiomyopathy (TTC) is characterized by clinical and electrocardio-graphic signs that mimic myocardial ischemia, typical left ventricular kinesis abnormalities, and no evidence of obstructive coronary disease. It is associated with emotional or physical stress usually in postmenopausal women. A major pathogenetic role is played by excessive sympathetic stimulation of the left ventricle. Only two cases of TTC have been described in patients on hemodialysis and one case has been described in a patient on peritoneal dialysis associated with peritonitis. We observed a case of TTC in a patient on nocturnal intermittent peritoneal dialysis with a transplanted kidney and loss of residual renal function. We found that she had suffered significant emotional stress immediately before the symptoms arose. The clinical features were typical ischemic chest pain and acute heart failure. Beta-blockers were the principal pharmacological treatment. The necessary ultrafiltration was obtained with peritoneal dialysis in automated modality, reducing the abdominal filling volumes according to the patient's compliance and modifying the glucose concentration according to her hemodynamic condition. The obtained ultrafiltration was appropriate and in accordance with the few experiences reported in the literature. The symptoms resolved within a week and the left ventricular kinesis and ejection fraction normalized in almost three weeks. This clinical case suggests that peritoneal dialysis, also in automated mode, can be as effective as extracorporeal ultrafiltration in the treatment of acute heart failure.

[Compound heterozygosis with novel AQP2 gene mutation in sisters affected by autosomal congenital nephrogenic diabetes insipidus].

Congenital nephrogenic diabetes insipidus (CNDI) is a rare inherited disorder, mostly caused by antidiuretic hormone receptor type 2 (ADHR2) gene mutations, which are inherited as X-linked traits. Less than 10% of cases are due to mutations in the aquaporin-2 (AQP2) gene, inherited in autosomal recessive or dominant manner. We report the case of two adult sisters, of 30 and 27 years of age, diagnosed in early infancy with X-linked CNDI. The patients' sex and family history did not fit in well with this diagnosis, so we sequenced the coding regions of the ADHR2 and AQP2 genes. As expected, no mutations were found in the ADHR2 gene, while we found a compound heterozygosis for two different mutations in the AQP2 gene. A missense mutation (c. 439G>A, p.Ala147Thr), an already known cause of CNDI, and a novel missense putative mutation of an adenine to cytosine at position 551 (c.551A>C), resulting in the substitution of asparagine with threonine at amino acid position 184 (p.Asn184Thr). This second mutation changes a fundamental extracellular Asn-Pro-Ala motif (NPA) of the AQP2 protein, inhibiting its function. Its pathogenicity has been confirmed by in silico predictions and is in line with comparable alterations to the intracellular NPA motif of the AQP2 protein.

[Peritoneal dialysis in adult patients with prune belly syndrome: an impossible challenge?]. / Dialisi peritoneale nel paziente adulto con sindrome di prune belly: sfida possibile?

Prune belly syndrome (PBS) is a rare congenital syndrome characterized by hypoplasia of the abdominal muscles, urinary tract malformations, and cryptorchidism in males. The estimated incidence is 1 in 35,000 to 50,000 live births. Chronic renal failure and end-stage renal disease (ESRD), due both to different degrees of renal hypoplasia or dysplasia and infectious complications, develops in 20-30% of patients who survive the neonatal period. No data are available on progression time to ESRD, owing to the variability of the phenotypic features of nephropathy. Nevertheless, PBS is primarily a pathology of pediatric interest as demonstrated, for example, by the reported average age at transplantation which usually does not exceed fifteen years of age. Therefore the need for renal replacement therapy (RRT) in adult patients with PBS is unusual. It is reasonable to suppose that the abdominal muscular defects may represent a limit for peritoneal dialysis (PD) utilization in PBS adult patients in many Kidney Units where, conversely, treatment with hemodialysis would be probably the easier choice. Here we describe the case of a 44 -year- old man with PBS who, at the age of 41, required RRT and was faced with the challenge of accepting PD. After more than three years of nocturnal automated peritoneal dialysis treatment we can safely say, as the following case illustrates, that PD is a feasible option in PBS adult patients.