[Innovations in peritoneal dialysis]. / Innovationen in der Peritonealdialyse.

Peritoneal dialysis used to be a common treatment for acute kidney failure that required dialysis. In favor of continuous, extracorporeal renal replacement procedures, it disappeared from the scene in the western world, whereas it continues to be used in structurally poor countries due to its simplicity and low resource intensity. Recently, the shortages in medical care in the context of the coronavirus disease 2019 (COVID-19) pandemic led to renewed worldwide interest in peritoneal dialysis as a safe option in acute kidney failure requiring dialysis. The introduction of biocompatible solutions 20 years ago was expected to reduce mortality or technical failure. Unfortunately, so far this could only be implied but not confirmed in studies. Immunomodulatory adjuvants are an innovative option which have the potential to improve the local immunocompetence and prevent the loss of peritoneal function. Currently, the vision of a wearable artificial kidney is getting closer. Intensification of dialysis dose also appears achievable with minimal dialysate volumes. In times of global warming, the regeneration of dialysates could not only save relevant amounts of water but also have a favorable impact on the CO2 balance. In summary, peritoneal dialysis is currently enjoying a comeback. This article describes the current and future developments of this procedure.

[Prospective monitoring of a university rheumatology outpatient clinic throughout the first wave of the COVID-19 pandemic : What lessons can be learned?] / Prospektive Verlaufsbeobachtung einer universitären Rheumaambulanzkohorte während der ersten Welle der COVID-19-Pandemie : Welche Lehren kann man ziehen?

BACKGROUND: In March 2020 the SARS-CoV­2 pandemic disseminated initially especially in Bavaria. At that time data on patients with rheumatic diseases and immunomodulatory treatment was lacking. OBJECTIVE: The aim was to analyze the influence of the SARS-CoV­2 pandemic on the clinical treatment strategy. MATERIAL AND METHODS: Between 16 March and 31 July 2020 all patients who consecutively presented at the rheumatology outpatient clinic of the Klinikum rechts der Isar of the Technical University of Munich were included in the study. Individual treatment adjustments were based on clinical judgment and the recommendations for action of the German Society for Rheumatology (DGRh). RESULTS: A total of 322 patients were included. The most frequent diagnosis was rheumatoid arthritis with 17%, ANCA-associated vasculitis (AAV) with 14% and SLE with 12%. Of the patients 262 were on DMARD treatment and 77 received oral glucocorticoids. There were 5 cases of suspected SARS-CoV­2 infection; however, no patient verifiably became ill due to COVID-19. In 40 patients, treatment adjustments were done due to the pandemic, whereby 3 patients developed a flare of the underlying disease. In retrospect, treatment de-escalation occurred most frequently in AAV, IgG4-related disease, immunosuppressive treatment with rituximab and the simultaneous presence of malignant diseases. CONCLUSION: The total lack of confirmed SARS-CoV­2 infections in an otherwise strongly affected region could indicate that the infection risk for SARS-CoV­2 is not substantially increased for patients with inflammatory rheumatic diseases. A continuation of most immunosuppressive medications therefore seems reasonable during the ongoing pandemic.

Adult macrophage activation syndrome-haemophagocytic lymphohistiocytosis: 'of plasma exchange and immunosuppressive escalation strategies' - a single centre reflection.

OBJECTIVE: In the context of systemic autoimmunity, that is systemic lupus erythematosus (SLE) or adult-onset Still's disease (AOSD), secondary haemophagocytic lymphohistiocytosis (HLH; also referred to as macrophage activation syndrome (MAS) or more recently MAS-HLH) is a rare and potentially life-threatening complication. Pathophysiological hallmarks are aberrant macrophage and T cell hyperactivation and a systemic cytokine flare, which generate a sepsis-like, tissue-damaging, cytopenic phenotype. Unfortunately, for adult MAS-HLH we lack standardized treatment protocols that go beyond high-dose corticosteroids. Consequently, outcome data are scarce on steroid refractory cases. Aside from protocols based on treatment with calcineurin inhibitors, etoposide, cyclophosphamide and anti-IL-1, favourable outcomes have been reported with the use of intravenous immunoglobulin (IvIG) and plasma exchange (PE). METHODS: Here we report a retrospective series of steroid refractory MAS-HLH, the associated therapeutic regimes and outcomes. RESULTS: In this single-centre experience, 6/8 steroid refractory patients survived (median follow-up: 54.4 (interquartile range: 23.3-113.3) weeks). All were initially treated with PE, which induced partial response in 5/8 patients. Yet, all patients required escalation of immunosuppressive therapies. One case of MAS-HLH in new-onset AOSD had to be escalated to etoposide, whereas most SLE-associated MAS-HLH patients responded well to cyclophosphamide. Relapses occurred in 2/8 cases. CONCLUSION: Together, early use of PE is at most a supportive measure, not a promising monotherapy of adult MAS-HLH. In refractory cases, conventional cytoreductive therapies (i.e. cyclophosphamide and etoposide) constitute potent and reliable rescue approaches, whereas IvIG, anti-thymoglobulin, and biologic agents appear to be less effective.

Identification and characterization of a defective CYP3A4 genotype in a kidney transplant patient with severely diminished tacrolimus clearance.

Cytochrome P450 3A4 (CYP3A4) is a major drug-metabolizing enzyme that is widely investigated. So far, no homozygous inactive variant has been described. We report on a 19-year-old kidney transplant patient suffering from Alport syndrome, who experienced unexpected high tacrolimus plasma trough levels during immunosuppressant therapy. Because nonadherence, liver failure, or drug-drug interactions could be excluded, we hypothesized a diminished metabolism of the drug caused by mutations in the main detoxification enzyme, CYP3A4. Exome sequencing revealed a novel single-nucleotide polymorphism (c.802C>T) resulting in a premature stop codon in CYP3A4 exon 5. Accordingly, no CYP3A4 protein could be detected in kidney biopsy tissue, and there was lack of expression in HepG2 cells transiently transfected with the mutated CYP3A4. In addition, the patient harbored inactive CYP3A5*3, resulting in loss of function of the entire CYP3A locus, explaining the deteriorated tacrolimus clearance. This is, to our knowledge, the first case of a complete failure of CYP3A4 in humans.

Modulation of dendritic cells and toll-like receptors by marathon running.

The focus of this study was to assess exercise-induced alterations of circulating dendritic cell (DC) subpopulations and toll-like receptor (TLR) expression after marathon running. Blood sampling was performed in 15 obese non-elite (ONE), 16 lean non-elite (LNE) and 16 lean elite (LE) marathon runners pre- and post-marathon as well as 24 h after the race. Circulating DC-fractions were measured by flow-cytometry analyzing myeloid DCs (BDCA-1+) and plasmacytoid DCs (BDCA-2+). We further analyzed the (TLR) -2/-4/-7 in peripheral blood mononuclear cells (rt-PCR/Western Blot) and the cytokines CRP, IL-6, IL-10, TNF-α and oxLDL by ELISA. After the marathon, BDCA-1 increased significantly in all groups [LE (pre/post): 0.35/0.47%; LNE: 0.26/0.50% and ONE: 0.30/0.49%; all p < 0.05]. In contrast, we found a significant decrease for BDCA-2 directly after the marathon (LE: 0.09/0.01%; LNE: 0.12/0.03% and ONE: 0.10/0.02%; all p < 0.05). Levels of TLR-7 mRNA decreased in all groups post-marathon (LE 44%, LNE 67% and ONE 52%; all p < 0.01), with a consecutive protein reduction (LE 31%, LNE 52%, ONE 42%; all p < 0.05) 24 h later. IL-6 and IL-10 levels increased immediately after the run, whereas increases of TNF-α and CRP-levels were seen after 24 h. oxLDL levels remained unchanged post-marathon. In our study population, we did not find any relevant differences regarding training level or body weight. Prolonged endurance exercise induces both pro- and anti-inflammatory cytokines. Anti-inflammatory cytokines, such as IL-10, may help to prevent excessive oxidative stress. Marathon running is associated with alterations of DC subsets and TLR-expression independent of training level or body weight. Myeloid and plasmacytoid DCs are differently affected by the excessive physical stress. Immunomodulatory mechanisms seem to play a key role in the response and adaptation to acute excessive exercise.

Interrelationship between aortic stiffness and proteinuria in chronic kidney disease.

Aortic stiffness and proteinuria are cardiovascular risk factors that are generally associated with each other. We analysed whether this is true for patients with chronic kidney disease (CKD). We hypothesized that in CKD patients of young age and predominant sole renal disease, aortic stiffness has no predictive value for proteinuria. In a cross-sectional setting, 144 patients with severe-to-mild CKD (estimated glomerular filtration rate (eGFR) 0 to <90 ml min(-1) 1.73 m(-2)) were analysed for stiffness, as measured using carotid-femoral pulse wave velocity (C-F PWV), and proteinuria, as determined using protein-creatinine ratio from morning spot urine. In stepwise linear regression analysis, C-F PWV predicted protein-creatinine ratio and vice versa. Younger patients (<50 years) with proteinuria had predominant glomerulonephritis. These were characterized by lower C-F PWV despite similar renal function when compared with younger patients without glomerulonephritis. We conclude that in CKD patients a general relationship exists between aortic stiffness and proteinuria. It is noted that this relation is lost in young CKD patients with predominant sole renal disease. In this study, C-F PWV is not predictive for proteinuria as renal disease is the leading cause of proteinuria.

Treatment of chronic allograft nephropathy at late stages using everolimus or FTY720 in combination with cyclosporine.

OBJECTIVE: In this study, we used combined treatment with cyclosporine (CsA)/everolimus (EVR) or CsA/FTY720 to affect ongoing chronic allograft nephropathy (CAN) compared with monotherapy with EVR or FTY720. BACKGROUND: CAN is an important cause of renal allograft loss. Immunosuppressive therapy is based on calcineurin inhibitors, which are associated with nephrotoxicity and decreasing graft function. Thus, alternative treatment regimens, including new immunosuppressants, such as EVR or FTY720, are of interest. We asked whether the combination of CsA with EVR or FTY720 ameliorated the development of CAN more effectively than monotherapy with EVR and/or FTY720 during the later stages of CAN. METHODS: Kidneys from Fisher rats were orthotopically transplanted into Lewis rats. Animals received CsA (1.5 mg/kg/d) for the first 10 days after transplantation. Animals were assigned to 6 groups: EVR (0.5 mg/kg/d), FTY720 (0.5 mg/kg/d), CsA (1.5 mg/kg/d), CsA+EVR (1.5 + 0.5 mg/kg/d), CsA+FTY720 (1.5 + 0.5 mg/kg/d), and vehicle (VEH). Treatment started at week 20. The observation period ended after 28 weeks. RESULTS: Treatment with EVR and FTY720 reduced proteinuria and glomerulosclerosis, suppressed lymphocyte and macrophage infiltration, and resulted in a greater number of apoptotic tubular and interstitial cells compared with the combined treatment groups and controls. CONCLUSION: Although EVR and FTY720 monotherapy delayed the progression of CAN, their combination with CsA had no beneficial effect.

Angiotensin type 1 and type 2 receptor blockade in chronic allograft nephropathy.

Angiotensin-II (Ang-II) type 1 (AT(1)) receptor blockers may delay the progression of chronic allograft nephropathy (CAN). However, neither the optimal time for initiating AT(1) receptor blockade in order to delay CAN potentially nor the role of Ang-II type 2 (AT(2)) receptors under AT(1) receptor blockade is known. Both AT receptors can regulate p53 expression and apoptosis. We investigated what time of initiation with AT(1) blockers most effectively delayed CAN as well as the role of the AT(2) receptor, and how angiotensin receptor blockade affected apoptosis and its regulating factors in this context in a rat model. Kidneys of Fisher (F344) rats were transplanted into Lewis rats. Animals were treated with AT(1) (candesartan) and/or AT(2) (PD123319) receptor antagonists, a calcium channel blocker, or vehicle (treatment periods: day -7 before to week 24 after transplantation (long term), week 12 to week 24 (late), day -7 to day +5 (early)) and observed the animals for 24 weeks. Reduction of proteinuria, grade of CAN, and number of apoptotic cells was most pronounced in animals receiving long-term AT(1) receptor blockade. A combined AT(1)/AT(2) blocker treatment reduced CAN similarly to AT(1) blocker treatment alone. The number of apoptotic cells and the level of p53 mRNA were significantly lower in long-term AT(1) blocker-treated animals. In summary, AT(1) receptor blockade delayed the progression of CAN, particularly in animals treated long term. Reduction of apoptosis could be related to these beneficial effects. The AT(2) receptor does not appear to play an important role in CAN.