Validation of the International IgA Nephropathy Prediction Tool in the Greek Registry of IgA Nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is among the commonest glomerulonephritides in Greece and an important cause of end-stage kidney disease (ESKD) with an insidious chronic course. Thus, the recently published International IgAN prediction tool could potentially provide valuable risk stratification and guide the appropriate treatment module. This study aimed to externally validate this prediction tool using a patient cohort from the IgAN registry of the Greek Society of Nephrology. METHODS: We validated the predictive performance of the two full models (with or without race) derived from the International IgAN Prediction Tool study in the Greek Society of Nephrology registry of patients with IgAN using external validation of survival prediction models (Royston and Altman). The discrimination and calibration of the models were tested using the C-statistics and stratified analysis, coefficient of determination ( R D 2 ) for model fit, and the regression coefficient of the linear predictor (ßPI), respectively. RESULTS: The study included 264 patients with a median age of 39 (30-51) years where 65.2% are men. All patients were of Caucasian origin. The 5-year risk of the primary outcome (50% reduction in estimated glomerular filtration rate or ESKD) was 8%. The R D 2 for the full models with and without race when applied to our cohort was 39 and 35%, respectively, and both were higher than the reported R D 2 for the models applied to the original validation cohorts (26.3, 25.3, and 35.3%, respectively). Harrel's C statistic for the full model with race was 0.71, and for the model without race was 0.70. Renal survival curves in the subgroups (<16th, ~16 to <50th, ~50 to <84th, and >84th percentiles of linear predictor) showed adequate separation. However, the calibration proved not to be acceptable for both the models, and the risk probability was overestimated by the model. CONCLUSIONS: The two full models with or without race were shown to accurately distinguish the highest and higher risk patients from patients with low and intermediate risk for disease progression in the Greek registry of IgAN.

Overview of infections as an etiologic factor and complication in patients with vasculitides.

Vasculitides, a form of inflammatory autoimmune disease targeting the vessels, constitute an entity with significant morbidity and mortality. Infections have long been associated with vasculitides as a result of the incident immunosuppression following treatment induction and maintenance. Several microbial pathogens have been described as etiologic factors of infections in this patient population according to the type of vessels affected. Intense research has also been recently conducted in the interplay between vasculitides and certain viral infections, namely human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2. Of note, a plethora of scientific evidence is available regarding the role of infections as triggering factors for vasculitides. Among the main mechanisms implicated in this direction are the activation of B and T cells, the direct endothelial insult, the immune complex-mediated vascular injury, and the cell-mediated, type IV hypersensitivity vessel damage. Therefore, this review aims to summarize all the available evidence concerning this bidirectional interplay between infections and vasculitides.

A Narrative Review of Recent Studies on the Role of Vitamin D in the Prevention of Cardiac and Renal Risk and Additional Considerations for COVID-19 Vulnerability.

The role of vitamin D in maintaining a healthy cardiovascular (CV) and the renal system has received increasing attention. Low vitamin D levels are associated with the incidence of hypertension, cardiac remodeling, and chronic congestive heart failure. Low vitamin D levels also influence renal disease progression and albuminuria deterioration. Moreover, recent research indicates that vitamin D deficiency can be a potential risk factor for coronavirus disease-19 (COVID-19) infection and poorer outcomes. Data are inconclusive as to whether supplementation with vitamin D agents reduces CV disease risk or COVID-19 severity. Conversely, in patients with kidney disease, vitamin D supplementation is associated with an improvement in kidney function and albuminuria. This narrative review considers recent data on the effects of vitamin D on the CV and renal system, as well as its possible role regarding COVID-19 complications.

Metformin-associated lactic acidosis and acute kidney injury in the era of COVID-19.

COVID-19, provoked by SARS-CoV-2, constitutes a global health issue with high rates of mortality. The presence of diabetes mellitus is associated with severe coronavirus COVID-19 as it is related to increased death rates in patients admitted to the intensive care unit. Acute kidney injury is a frequent complication among patients hospitalized for COVID-19 and is met with high morbidity and mortality. Here, we present a case of a diabetic patient with acute kidney injury, metformin-associated lactic acidosis, and COVID-19. Lactic acidosis is a relatively rare but noteworthy complication of metformin use. However, the combination of those life-threatening situations could prove fatal for the patients despite optimal medical care.

Dyslipidemia in Chronic Kidney Disease: Contemporary Concepts and Future Therapeutic Perspectives.

BACKGROUND: Chronic kidney disease (CKD) is an increasingly prevalent disease state met with great morbidity and mortality primarily resulting from the high incidence of adverse cardiovascular outcomes. Therapeutic strategies in this patient population aim at controlling modifiable cardiovascular risk factors, including dyslipidemia. SUMMARY: In this review article, we first provide the latest pathophysiologic evidence regarding the altered dyslipidemia pattern in CKD, followed by its contemporary management according to the latest guidelines. Moreover, we present the current progress regarding the emerging therapeutic strategies. Key Messages: The presence of renal impairment leads to alterations in cholesterol structure, metabolism, and reverse transport paired with increased oxidative stress. Statins remain the cornerstone of dyslipidemia management in patients with kidney dysfunction who are at risk for cardiovascular events. However, their efficacy is debatable in end-stage renal disease under renal replacement therapy. Therefore, novel treatment approaches aiming at hypertriglyceridemia, proprotein convertase subtilisin/kexin type 9, and lipoprotein(a) are under rigorous investigation while the research of gut microbiome might provide additional mechanistic and therapeutic insight.

The role of mycophenolate in the treatment of antineutrophil cytoplasmic antibody-associated vasculitis.

Mycophenolic acid, the active metabolite for mycophenolate mofetil and mycophenolic sodium, is a strong, noncompetitive, reversible inhibitor of inosine monophosphate dehydrogenase, the key enzyme in de novo synthesis of guanosine nucleotides leading to selective inhibition of lymphocyte proliferation. Mycophenolic acid has been evaluated as induction and remission maintenance agent in the treatment of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Since the course of disease of AAV usually requires long term immunosuppression, mycophenolate has been explored as a less toxic agent compared to cyclophosphamide and azathioprine. Mycophenolate is a potent immunosuppressive agent in the therapy of AAV, non-inferior to other available drugs with comparable side effect profile. Therefore, it could be a valuable alternative in cases of toxicity with life threatening side effects or intolerance to cyclophosphamide or azathioprine, in cases with high cumulative dose of cyclophosphamide, but also in cases with insufficient response. Several studies have shown a higher relapse rate following discontinuation of mycophenolate or in mycophenolate treated subjects that raises concerns about its usefulness in the treatment of AAV. This review describes the efficacy of mycophenolate in AAV as remission induction agent, as remission maintenance agent, and as therapeutic option in relapsing AAV disease, the relapse rate following discontinuation of mycophenolate, and the adverse events related to mycophenolate treatment.

Generalized Pustular Psoriasis (Von Zumbusch Type) Following Renal Transplant: A Case Report.

Generalized pustular psoriasis appears as an uncommon variant form of psoriasis consisting of widespread pustules on an erythematous background (von Zumbusch). A 39-year-old male patient with a history of plaque psoriasis since the age of 9 who had an acute relapse of generalized pustular psoriasis 12 days following a successful renal transplantation is presented. Despite administered immunosuppression for transplantation, the addition of cyclosporine and methotrexate did not reverse the ongoing process of disease and the patient died on the 57th posttransplant day due to multiorgan failure subsequent to severe bone marrow suppression.

Successful Living-Related Renal Allograft in a Recipient With Factor V Leiden Deficiency: A Case Report.

Thrombophilia due to activated protein C resistance (Leiden mutation) is the most common inherited thrombophilic disorder with 5% incidence in whites. Renal transplant of these patients entails a risk of vascular thrombosis soon after the transplant; and acute rejection episodes and graft loss within the first year. We present a case of a successful living-related renal transplant in man with a recent history of repeat episodes of vascular access thrombosis attributed to inherited thrombophilia (heterozygosity for factor V mutation Q506 and homozygosity for mutation T677 for methylene-tetrahydrofolate reductase). Transplant recipient was administered anticoagulation therapy with low molecular weight heparin pre- and postoperatively. No thrombotic or hemorrhagic events occurred posttransplant. A high suspicion of thrombophilic disorders in patients with end-stage renal disease with vascular access thrombotic events should be screened further to prevent failure of a subsequent renal transplant. Inherited thrombophilic disorders may not exclude living-related kidney transplant provided that anticoagulation therapy is admin-istered perioperatively.

Fournier's gangrene due to perioperative iatrogenic colon perforation in a renal transplant recipient.

Fournier's gangrene is not a common cause of morbidity in renal transplant recipients, but, if it occurs, it is difficult to treat because of the immunosuppression and associated increased mortality rate. We describe the case of a male patient who underwent renal transplantation with complicated post-operative course, resulting in cecum perforation (thermal injury due to cautery use during transplantation) requiring exploratory laparotomy and cecostomy. A few days later, he developed Fournier's gangrene and urgent radical surgical debridement of the scrotum was performed, along with aggressive antibiotic regimen and the immunosuppressive treatment was modified. Subsequently, the patient underwent scheduled cecostomy closure (right hemicolectomy), while the scrotum trauma healed with tertiary intention. Epidemiologic characteristics, clinical presentation, diagnostic workup, therapeutic options and morbidity-mortality rates of Fournier's gangrene are reviewed, emphasizing the role of immunosuppression in renal transplant recipients to disease development.

Successful endovascular treatment of transplant intrarenal artery stenosis in renal transplant recipients: Two case reports.

Transplant renal artery stenosis (TRAS) is a relatively rare complication after renal transplantation. The site of the surgical anastomosis is most commonly involved, but sites both proximal and distal to the anastomosis may occur, as well. Angioplasty is the gold standard for the treatment of the stenosis, especially for intrarenal lesions. We report two cases of intrarenal TRAS and successful management with angioplasty without stent placement. Both patients were male, 44 and 55 years old respectively, and they presented with elevated blood pressure or serum creatinine within three months after transplantation. Subsequently, they have undergone angioplasty balloon dilatation with normalization of blood pressure and serum creatinine returning to baseline level. Percutaneous transluminal balloon renal angioplasty is a safe and effective method for the treatment of the intrarenal TRAS.

Neutrophil Gelatinase-Associated Lipocalin as a Biomarker of Acute Kidney Injury in Patients with Morbid Obesity Who Underwent Bariatric Surgery.

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL) has been identified as a biomarker of acute kidney injury (AKI) that could contribute to early diagnosis and effective management of AKI. The purpose of this study was to evaluate NGAL as a predictive marker of AKI in patients with clinically severe obesity (BMI >50) who underwent biliopancreatic diversion surgery. PATIENTS AND METHODS: We prospectively studied 23 patients with clinically severe obesity who underwent biliopancreatic bypass surgery. NGAL was measured using chemiluminescent microparticle immunoassay in three urine samples collected from each patient before surgery (first sample), 2-6 h after surgery (second sample) and on the first postoperative day (third sample). RESULTS: Renal function was evaluated using serum creatinine values, which were 0.91 ± 0.26 mg/dl before surgery, 0.87 ± 0.31 mg/dl immediately after surgery and 0.92 ± 0.62 mg/dl on the fifth postoperative day. During the immediate postoperative period, AKI was observed in 2 patients, one of whom required renal replacement therapy with hemodialysis. In both patients, urine NGAL increased within the first postoperative hours before the values of serum creatinine increased. CONCLUSION: Urine NGAL in patients with clinically severe obesity, which was surgically treated, might be a potential biomarker of early AKI detection. Further research is required in order to confirm these results observed in a small number of patients who developed postoperative AKI and make recommendations for predictive NGAL values in patients who underwent bariatric surgery.

Cytomegalovirus polyradiculopathy of late onset in a young renal transplant recipient.

Although cytomegalovirus (CMV) disease in CMV IgM/IgG-negative renal transplant recipients from CMV-positive donors (D+/R-) can occur after discontinuation of prophylaxis treatment as a flu-like syndrome or tissue invasive disease, involvement of the central nervous system is rare. Here, we report a case of CMV polyradiculopathy 6 months after renal transplantation that presented as a Guillain-Barre like syndrome and was successfully treated with foscarnet. This case highlights an uncommon aspect of CMV invasive disease which we should keep in mind in CMV (D+/R-) renal transplant recipients.

Increased Prevalence and Severity of Coronary Artery Calcification in Patients with Chronic Kidney Disease Stage III and IV.

BACKGROUND: Cardiovascular disease (CVD) is the main cause of mortality in patients with chronic kidney disease (CKD). The pathophysiology of coronary artery disease in CKD is multifactorial including, in addition to traditional risk factors (hypertension, hyperlipidemia, diabetes mellitus), parameters related to uremia. METHODS: The study consisted of measuring coronary artery calcification (CAC) score in patients with CKD stage III and IV without history of CVD and in a group of controls with normal renal function matched for age, gender and risk factors using multi-detector computed tomography. RESULTS: The study included 49 patients and 49 controls. CAC was present in 79.6% in the CKD group versus 59.2% in the control group (p = 0.028). The median CAC score value in CKD patients was 139 (interquartile range (IQR): 23-321) versus 61 (IQR: 6-205) in controls (p = 0.007). CAC was associated with traditional risk factors such as older age, hypertension and baseline cardiovascular risk score, while CKD patients with severe calcification had marginally lower estimated glomerular filtration rate and increased levels of parathormone. CONCLUSIONS: CAC is more frequent and severe in patients with CKD stage III and IV compared to matched controls with normal renal function, even though kidney disease-related parameters are not directly correlated with intensity of calcification.

Fulminant pancytopenia due to cytomegalovirus infection in an immunocompetent adult.

A case of severe and irreversible pancytopenia secondary to acute primary cytomegalovirus infection in an immunocompetent woman is described. The patient presented with thrombocytopenia, lymphopenia, anemia, and abnormal liver function tests. Treatment with corticosteroids and intravenous immunoglobulin was ineffective in reconstituting hemopoiesis. The patient developed severe sepsis and eventually expired.

The accumulated experience with the use of mycophenolate mofetil in primary glomerulonephritis.

IMPORTANCE OF THE FIELD: The use of mycophenolate mofetil (MMF) has been extended from renal transplantation to the treatment of glomerulonephritis. MMF has been used in patients with steroid- and ciclosporin A (CsA)-dependent or -resistant idiopathic nephrotic syndrome and in patients with deteriorating renal function or adverse reactions to other drugs. MMF has been also used in patients with membranous and IgA nephropathy after failure of other regimens as well as initial treatment. AREAS COVERED IN THIS REVIEW: The rationale of MMF treatment in primary glomerulonephritis is based in its antifibrotic and antiproteinuric effects. The mechanism of action is described; the results of cohort and randomized trials in minimal change disease, focal segmental glomerulosclerosis, idiopathic membranous nephropathy and IgA nephropathy are presented along with the adverse reactions profile and the expert opinion. WHAT THE READER WILL GAIN: This is an up-to-date review providing insight on this novel agent that is increasingly used in the therapeutics of primary glomerulonephritis. TAKE HOME MESSAGE: Although the results are conflicting, MMF seems to be effective at least in some patients, who do not respond to corticosteroids, ciclosporin or cytotoxic drugs. However, the experience with MMF in primary glomerulonephritis is limited and further research is required in order to establish MMF in the treatment of patients with glomerular disease.

A CD8+ T cell transcription signature predicts prognosis in autoimmune disease.

Autoimmune diseases are common and debilitating, but their severe manifestations could be reduced if biomarkers were available to allow individual tailoring of potentially toxic immunosuppressive therapy. Gene expression-based biomarkers facilitating such tailoring of chemotherapy in cancer, but not autoimmunity, have been identified and translated into clinical practice. We show that transcriptional profiling of purified CD8(+) T cells, which avoids the confounding influences of unseparated cells, identifies two distinct subject subgroups predicting long-term prognosis in two autoimmune diseases, antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), a chronic, severe disease characterized by inflammation of medium-sized and small blood vessels, and systemic lupus erythematosus (SLE), characterized by autoantibodies, immune complex deposition and diverse clinical manifestations ranging from glomerulonephritis to neurological dysfunction. We show that the subset of genes defining the poor prognostic group is enriched for genes involved in the interleukin-7 receptor (IL-7R) pathway and T cell receptor (TCR) signaling and those expressed by memory T cells. Furthermore, the poor prognostic group is associated with an expanded CD8(+) T cell memory population. These subgroups, which are also found in the normal population and can be identified by measuring expression of only three genes, raise the prospect of individualized therapy and suggest new potential therapeutic targets in autoimmunity.

Fulminant pancytopenia due to cytomegalovirus infection in an immunocompetent adult

A case of severe and irreversible pancytopenia secondary to acute primary cytomegalovirus infection in an immunocompetent woman is described. The patient presented with thrombocytopenia, lymphopenia, anemia, and abnormal liver function tests. Treatment with corticosteroids and intravenous immunoglobulin was ineffective in reconstituting hemopoiesis. The patient developed severe sepsis and eventually expired.

Novel expression signatures identified by transcriptional analysis of separated leucocyte subsets in systemic lupus erythematosus and vasculitis.

OBJECTIVE: To optimise a strategy for identifying gene expression signatures differentiating systemic lupus erythematosus (SLE) and antineutrophil cytoplasmic antibody-associated vasculitis that provide insight into disease pathogenesis and identify biomarkers. METHODS: 44 vasculitis patients, 13 SLE patients and 25 age and sex-matched controls were enrolled. CD4 and CD8 T cells, B cells, monocytes and neutrophils were isolated from each patient and, together with unseparated peripheral blood mononuclear cells (PBMC), were hybridised to spotted oligonucleotide microarrays. RESULTS: Using expression data obtained from purified cells a substantial number of differentially expressed genes were identified that were not detectable in the analysis of PBMC. Analysis of purified T cells identified a SLE-associated, CD4 T-cell signature consistent with type 1 interferon signalling driving the generation and survival of tissue homing T cells and thereby contributing to disease pathogenesis. Moreover, hierarchical clustering using expression data from purified monocytes provided significantly improved discrimination between the patient groups than that obtained using PBMC data, presumably because the differentially expressed genes reflect genuine differences in processes underlying disease pathogenesis. CONCLUSION: Analysis of leucocyte subsets enabled the identification of gene signatures of both pathogenic relevance and with better disease discrimination than those identified in PBMC. This approach thus provides substantial advantages in the search for diagnostic and prognostic biomarkers in autoimmune disease.

Community-acquired methicillin-resistant Staphylococcus aureus as a cause of rapidly progressing pyelonephritis with pyonephrosis, necessitating emergent nephrectomy.

In this article, we describe the first, to our knowledge, reported case of severe bacteremic upper urinary tract infection with pyonephrosis-in the context of prior chronic urinary tract disease-caused by community-acquired methicillin-resistant Staphylococcus aureus (MRSA). The patient presented with fever and constitutional symptoms, and computed tomography revealed extensive renal parenchymal infection along with a staghorn calculus and dilatation of the pyelocalyceal system. His clinical condition rapidly deteriorated, and he developed uncontrollable sepsis, necessitating an emergent nephrectomy. Significant pyonephrosis was noted during surgery. Blood cultures yielded MRSA, and molecular analysis (by polymerase chain reaction) of the MRSA strains from blood and wound fluid showed that they were Panton-Valentine leukocidin positive and they also possessed SCCmecA type IV. Postoperatively, the patient was treated with intravenous vancomycin for 3 weeks and had a favorable outcome.

Total parathyroidectomy without autotransplantation in dialysis patients and renal transplant recipients, long-term follow-up evaluation.

BACKGROUND: Persistent secondary hyperparathyroidism not responding to medication is treated successfully with surgical excision of parathyroid glands (total parathyroidectomy [PTX]). PTX without autotransplantation of parathyroid glands excludes the risk for recurrence of hyperparathyroidism. METHODS: During the years 2002 to 2005, 36 total parathyroidectomies were performed in 33 patients: 21 dialysis patients because of end-stage renal disease and 12 renal transplant recipients. RESULTS: PTX without autotransplantation was performed successfully in 33 patients, whereas 3 patients were reoperated for remaining parathyroid glands. Immediate improvement of clinical symptoms and a decrease of serum calcium and parathormone levels were observed after surgical procedures. Oral replacement treatment with vitamin D (1a-calcidiol) and calcium was commenced and long-term follow-up evaluation (23.5 +/- 7.6 mo) showed that calcium homeostasis was controlled adequately. CONCLUSIONS: PTX without autotransplantation is a safe and effective surgical procedure for the treatment of resistant secondary hyperparathyroidism with immediate response of clinical symptoms. Replacement treatment with vitamin D and calcium provides satisfactory coverage of individual needs.