Therapeutic Plasmapheresis: a revision of literature.

BACKGROUND: Therapeutic Plasmapheresis (TP) is an extracorporeal therapy that allows the removal of pathogens from plasma. The role of TP in immuno-mediated diseases and toxic conditions has been of interest for decades. SUMMARY: We reviewed the recent literature on the application and the optimal choice of TP technique ranging from Plasma Exchange, Double Filtration Plasmapheresis, Rheopheresis, Immunoadsorptions and Lipidoapheresis. In addition, we report our experience in the application of TP for various diseases ranging in different medical specialties, following the American Society for Apheresis (ASFA) recommendations. KEY MESSAGES: Overall patients receiving TP showed an improvement in clinical and laboratory parameters. Our review and single center experience suggest a benefit of the application of TP in multiple clinical disciplines.

[An overview on acute kidney injury in COVID-19].

SARS-CoV-2 infection is responsible for the coronavirus disease 2019 (COVID-19). In the complex scenario of COVID-19, it is also possible to find patients with renal damage. The pathogenesis is multifactorial and not unique, and the clinical presentation may include urinary alterations, such as proteinuria and hematuria, accompanied with reduced renal function, or not. Acute kidney injury (AKI) is not uncommon, especially among critically ill patients hospitalized in intensive care unit. AKI is a negative prognostic factor and is associated with high in-hospital mortality. An early diagnosis of AKI and the assessment of any risk factors allow the nephrologist to implement appropriate therapeutic strategies, such as pharmacological or extracorporeal support. Still, mortality in patients with AKI during COVID-19 remains high. COVID-19 AKI is a quickly evolving field of study.

[Practical approach to patient therapy affected by Autosomal Dominant Autosomic Polycystic Kidney Disease].

The Autosomal Dominant Polycystic Kidney Disease(ADPKD) is the most frequent renal genetic condition and involves 7 to 10% of subjects undergoing renal replacement therapy. It is estimated that between 24,000 and 34,000 subjects in Italy are affected by this condition. For an illness that has long been neglected due to a lack of treatment options, an attractive treatment possibility is now available: tolvaptan has shown clinical efficacy regarding disease progression in two clinical trials (ADPKD patients with mild renal failure and ADPKD patients with advanced renal failure). The possible liver toxicity expressed in about 4% of the subjects exposed to the drug and an important aquaretic effect suggest prudence and attention in the use of this new molecule. Based on these critical points, some clinicians with direct experience in the use of the drug have briefly collected in the pages to follow the main clinical recommendations for the treatment of ADPKD patints. The recommendations concern the general approach to the patient affected by ADPKD but with particular attention to the aspects related to the new treatment. The delicate task of introducing the opportunities and limitations of the offered therapy to the patient will be deepened. Finally, the document wants to suggest how best to organize a clinic dedicated to this condition.

Lithium increases ammonium excretion leading to altered urinary acid-base buffer composition.

Previous reports identify a voltage dependent distal renal tubular acidosis (dRTA) secondary to lithium (Li+) salt administration. This was based on the inability of Li+-treated patients to increase the urine-blood (U-B) pCO2 when challenged with NaHCO3 and, the ability of sodium neutral phosphate or Na2SO4 administration to restore U-B pCO2 in experimental animal models. The underlying mechanisms for the Li+-induced dRTA are still unknown. To address this point, a 7 days time course of the urinary acid-base parameters was investigated in rats challenged with LiCl, LiCitrate, NaCl, or NaCitrate. LiCl induced the largest polyuria and a mild metabolic acidosis. Li+-treatment induced a biphasic response. In the first 2 days, proper urine volume and acidification occurred, while from the 3rd day of treatment, polyuria developed progressively. In this latter phase, the LiCl-treated group progressively excreted more NH4+ and less pCO2, suggesting that NH3/NH4+ became the main urinary buffer. This physiological parameter was corroborated by the upregulation of NBCn1 (a marker of increased ammonium recycling) in the inner stripe of outer medulla of LiCl treated rats. Finally, by investigating NH4+ excretion in ENaC-cKO mice, a model resistant to Li+-induced polyuria, a primary role of the CD was confirmed. By definition, dRTA is characterized by deficient urinary ammonium excretion. Our data question the presence of a voltage-dependent Li+-induced dRTA in rats treated with LiCl for 7 days and the data suggest that the alkaline urine pH induced by NH3/NH4+ as the main buffer has lead to the interpretation dRTA in previous studies.

Delay in Renal Hemodynamic Response to a Meat Meal in Severe Obesity.

BACKGROUND/AIMS: Little information is available about the tubular functions and the renal adjustments that take place in obese subjects after a protein meal. How the excess fat may affect renal response to dietary proteins is currently only partially understood. This paper aims to address (i) whether severe obesity, in the absence of other comorbidities, is responsible of kidney dysfunction at either the glomerular or the tubular level and (ii) whether it compromises renal adaptations to a large protein meal. METHODS: Twenty-eight obese subjects without albuminuria, along with 20 control subjects, age and gender matched, have been studied. The glomerular filtration rate (GFR; inulin clearance), renal plasma flow (p-aminohippurate clearance), the proximal tubular function (lithium clearance), the fractional excretion of sodium (FPRNa) have been measured at the basal level (steady state) and after a protein meal (perturbation). RESULTS: Under steady state conditions, filtration fraction, proximal tubular sodium handling and the FPRNa were not significantly different in non proteinuric obese subjects compared with controls. However, a protein meal led to a delayed glomerular hyperfiltration in obese patients compared with controls. CONCLUSION: This study shows that obese patients, in the absence of significant comorbidities, have a normal proximal tubule Na+ absorption at basal; conversely, these subjects showed a different response to a protein meal compared with normal subjects in terms of changes of GFR. Overall, these results suggest that the modified hemodynamic response to a protein meal might be the earliest hallmark of future kidney dysfunction in obese subjects.

[DFPP in myasthenia gravis: case report]. / La filtrazione a cascata nel trattamento della miastenia grave: caso clinico.

INTRODUCTION: Myasthenia Gravis (MG) is a neuromuscular disease due to a decrease in the number of acetylcholine receptors (AChR) present at the level of the neuromuscular junction. It is characterized by weakness and muscle fatigue. The pathogenesis of MG would seem to be autoimmune (autoantibodies against AChR, Musk, Titin). The treatment of MG includes acetylcholinesterase inhibitors, immunosuppressants, intravenous human immunoglobulin, thymectomy and therapeutic apheresis. MATERIALS AND METHODS: We report a case of a 40-year-old woman, suffering from MG, subjected to thymectomy, in therapy with corticosteroids, azathioprine and antagonist of acetylcholinesterase. The patient came under our observation for the appearance of a severe acute worsening of neurological disease unresponsive to medical therapy. She underwent a series of four treatments, every other day, of double filtration plasmapheresis (DFPP). RESULTS AND DISCUSSION: The DFPP removed from the patient's blood high-molecular-weight substances. It showed a reduction of Immunoglobulins, Fibrinogen, C3 and C4 complement fractions and anti ACh-R Ab.The DFPP resulted in disappearance of symptoms with improvement in motor and sensory conduction parameters evaluated by electromyography. CONCLUSION: The DFPP quickly reduces the anti ACh-R Ab and anti Titin Ab, as well as the risk of infections and allergies, compared to Plasma Exchange. It improves clinical symptoms, therefore it is proved to be an effective therapy for the acute exacerbation of MG.