Computational complexity of kk-stable matchings

We study deviations by a group of agents in the three main types of matching markets: the house allocation, the marriage, and the roommates models. For a given instance, we call a matching $k$-stable if no other matching exists that is more beneficial to at least $k$ out of the $n$ agents. The concept generalizes the recently studied majority stability. We prove that whereas the verification of $k$-stability for a given matching is polynomial-time solvable in all three models, the complexity of deciding whether a $k$-stable matching exists depends on $\frac{k}{n}$ and is characteristic to each model.Comment: SAGT 202

Tartós immunonephrológiai gondozásban részesült lupus nephritises betegeink hosszú távú kezelési eredményei

Introduction: Lupus nephritis is the most severe complication of systemic lupus erythematosus (SLE), its development and the effectiveness of immunosuppressive therapy substantially influence patients' quality of life and survival.Aim: In this retrospective observational investigation, the long term-outcome of patients with lupus nephritis, followed at the St. Margit Hospital Immunonephrological Outpatient Clinic, was evaluated.Results: Between 1997 December 1 and 2019 April 30, 73 patients (age 33.7 +/- 15 years, 82% female, 18% male) were under care with median observation of 119 [between 3-264] months. At diagnosis, eGFR showed 68 [7-120] ml/min, proteinuria was 2800 [23-16812] mg/day; 10 patients needed dialysis treatment acutely. Renal biopsy, performed in 68 patients, proved proliferative lupus nephritis in 55 and pure membranous lupus nephritis in 6 patients. Administering combined immunosuppressive therapy, complete remission was achieved in 50 and partial remission in 21 cases; one or repeated relapses developed in 28 subjects. Two patients, by the time they got under our care, had already required chronic dialysis, and in the long term, three more patients progressed to end-stage renal disease requiring renal replacement therapy. Renal fUnction stabilized in all other participants, clinical activity of SLE, SLEDAI score, complement levels and immunserology results improved significantly.Conclusions: Lupus nephritis can be effectively treated by combined induction and prolonged maintenance immunosuppression, but to prevent progression of the disease, long-term care is necessary by co-operation of nephrologist and immunologist. To provide adequate prevention and therapy of the SLE's multiorgan involvement and also the potential complications of immunosuppression, multidisciplinary team is needed with all specialists who may facilitate these patients' complex care. For the long-term management of patients with lupus nephritis, the nephrologists have to be responsible, and the multidisciplinary teams also have to be under their direction

Optimal Kidney Exchange with Immunosuppressants

Algorithms for exchange of kidneys is one of the key successful applications in market design, artificial intelligence, and operations research. Potent immunosuppressant drugs suppress the body's ability to reject a transplanted organ up to the point that a transplant across blood- or tissue-type incompatibility becomes possible. In contrast to the standard kidney exchange problem, we consider a setting that also involves the decision about which recipients receive from the limited supply of immunosuppressants that make them compatible with originally incompatible kidneys. We firstly present a general computational framework to model this problem. Our main contribution is a range of efficient algorithms that provide flexibility in terms of meeting meaningful objectives. Motivated by the current reality of kidney exchanges using sophisticated mathematical-programming-based clearing algorithms, we then present a general but scalable approach to optimal clearing with immunosuppression; we validate our approach on realistic data from a large fielded exchange.Comment: AAAI 202

FHR-5 Serum Levels and CFHR5 Genetic Variations in Patients With Immune Complex-Mediated Membranoproliferative Glomerulonephritis and C3-Glomerulopathy

Factor H-related protein 5 (FHR-5) is a member of the complement Factor H protein family. Due to the homology to Factor H, the main complement regulator of the alternative pathway, it may also be implicated in the pathomechanism of kidney diseases where Factor H and alternative pathway dysregulation play a role. Here, we report the first observational study on CFHR5 variations along with serum FHR-5 levels in immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G) patients together with the clinical, genetic, complement, and follow-up data.A total of 120 patients with a histologically proven diagnosis of IC-MPGN/C3G were enrolled in the study. FHR-5 serum levels were measured in ELISA, the CFHR5 gene was analyzed by Sanger sequencing, and selected variants were studied as recombinant proteins in ELISA and surface plasmon resonance (SPR).Eight exonic CFHR5 variations in 14 patients (12.6%) were observed. Serum FHR-5 levels were lower in patients compared to controls. Low serum FHR-5 concentration at presentation associated with better renal survival during the follow-up period; furthermore, it showed clear association with signs of complement overactivation and clinically meaningful clusters.Our observations raise the possibility that the FHR-5 protein plays a fine-tuning role in the pathogenesis of IC-MPGN/C3G

Simple, readily available clinical indices predict early and late mortality among patients with ANCA-associated vasculitis

BACKGROUND: The early identification of patients with ANCA-associated vasculitis (AAV) who are at increased risk for inferior clinical outcome at the time of diagnosis might help to optimize the immunosuppressive therapy. In this study we wanted to determine the predictive value of simple clinical characteristics, which may be applicable for early risk-stratification of patients with AAV. METHODS: We retrospectively analyzed the outcome of 101 consecutive patients with AAV receiving a protocolized immunosuppressive therapy. Baseline Birmingham Vasculitis Activity Score (BVAS) and non-vasculitic comorbidities were computed, then predictors of early (90 days) mortality, infectious death, relapse and end stage kidney disease (ESKD) were evaluated. RESULTS: The baseline comorbidity score independently predicted early mortality (HR 1.622, CI 1.006-2.614), and showed association with infectious mortality (HR 2.056, CI 1.247-3.392). Patients with BVAS at or above median (=21) had worse early mortality in univariable analysis (HR 3.57, CI 1.039-12.243) (p = 0.031), and had more frequent relapses (p = 0.01) compared to patients with BVAS below median. CONCLUSIONS: Assessing baseline comorbidities, beside clinical indices characterizing the severity and extension of AAV, might help clinicians in risk-stratification of patients. Future prospective studies are needed to investigate whether therapies based on risk-stratification could improve both short term and long term survival

Validation of distinct pathogenic patterns in a cohort of membranoproliferative glomerulonephritis patients by cluster analysis

Background: A novel data-driven cluster analysis identified distinct pathogenic patterns in C3-glomerulopathies and immune complex-mediated membranoproliferative glomerulonephritis. Our aim was to replicate these observations in an independent cohort and elucidate disease pathophysiology with detailed analysis of functional complement markers. ----- Methods: A total of 92 patients with clinical, histological, complement and genetic data were involved in the study, and hierarchical cluster analysis was done by Ward method, where four clusters were generated. ----- Results: High levels of sC5b-9 (soluble membrane attack complex), low serum C3 levels and young age at onset (13 years) were characteristic for Cluster 1 with a high prevalence of likely pathogenic variations (LPVs) and C3 nephritic factor, whereas for Cluster 2-which is not reliable because of the small number of cases-strong immunoglobulin G staining, low C3 levels and high prevalence of nephritic syndrome at disease onset were observed. Low plasma sC5b-9 levels, decreased C3 levels and high prevalence of LPV and sclerotic glomeruli were present in Cluster 3, and patients with late onset of the disease (median: 39.5 years) and near-normal C3 levels in Cluster 4. A significant difference was observed in the incidence of end-stage renal disease during follow-up between the different clusters. Patients in Clusters 3-4 had worse renal survival than patients in Clusters 1-2. ----- Conclusions: Our results confirm the main findings of the original cluster analysis and indicate that the observed, distinct pathogenic patterns are replicated in our cohort. Further investigations are necessary to analyse the distinct biological and pathogenic processes in these patient groups