Renal involvement in autoimmune connective tissue diseases

Growth arrest-specific protein 6 as a marker of nephritis in systemic sclerosis and juvenile systemic lupus erythematosus patients

Background: Renal impairments commonly occur as a complication of autoimmune connective tissue diseases (CTDs). Therefore, early nephritis prediction is vital for patient outcomes. Growth Arrest-Specific Protein 6 (GAS6) was found to be upregulated in many types of inflammatory renal disease, including diabetic nephropathy.Aim: To evaluate GAS6 as a predictor of renal impairment in adults with systemic sclerosis (SSc) and children with systemic lupus Erythematosus (SLE).Methods: The study included 60 patients with SSc and 40 children with SLE. The serum level of GAS6 was measured using the ELISA technique. In adults with SSc, total proteins in 24-h urine concentration of >300 mg/24 h indicated renal inflammation, while in children with SLE, nephritis was diagnosed by abnormal renal pathology.Results: In SSc patients, GAS6 significantly increased in patients with proteinuria. GAS6 is an independent predictor of nephritis with an odds ratio (OR) of 1.06 and a 95% confidence interval (CI) of 1.0-1.1. at cutoff 12.2 ng/mL GAS6 predicted proteinuria with sensitivity 86.7% (95% CI: 59.5% to 98.3%), specificity 57.8% (95% CI: 42.1% to 72.3%), positive predictive value 40.6% (95% CI: 31.5% to 50.4%), negative predictive value 92.9% (95% CI: 77.7% to 97.73%), and accuracy 65.0% (95% CI: 51.6% to 76.9%). In SLE patients, Serum GAS6 did not differ significantly between children with and without lupus nephritis.Conclusion: GAS6 is an independent predictor of nephritis in patients with SSc. However, there is no association between GAS6 and nephritis in juvenile patients with SLE.

Polyarthritis in Sjögren's Syndrome: Difficulties in Distinguishing Extraglandular Manifestation and Associated Rheumatoid Arthritis

Aim of the study was to investigate the demographic data and disease course characteristics of patients with Sjögren's syndrome (SS) and inflammatory joint pain of various origins and to search for factors that might help with the distinction of polyarthritis as an extraglandular manifestation and rheumatoid arthritis as an associated systemic autoimmune disorder. A total of 355 patients were retrospectively analyzed, 128 of whom served as controls (SS-C), while 159 had polyarthritis as an extraglandular symptom of Sjögren's syndrome (SS-pa) and 68 were diagnosed as having associated rheumatoid arthritis (SS-RA). The patients without any inflammatory joint manifestations were significantly older than the SS-pa patients, while, for the SS-RA group, the difference was not significant. The onset of joint pain appeared significantly earlier in the SS-RA patients. Regarding either extraglandular manifestations or associated autoimmune disorders, there were significant differences between the controls and both SS-pa and SS-RA groups, while no significant difference was found between the SS-pa and SS-RA groups. Thus, laboratory and imaging methods should be used to differentiate between the two conditions, but laboratory biomarkers are even more important for early diagnosis. A ROC curve analysis showed an acceptable diagnostic accuracy in differentiating between SS-pa and SS-RA patients using a binary logistic regression model, where highly positive rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) values, kidney involvement, and anti-Ro/SS-A positivity were shown to significantly raise the odds of having RA, whereas anti-La/SS-B positivity seemed to have a protective role, since it significantly decreased the odds of having it. Further biomarkers are needed to better classify SS patient cohorts with inflammatory joint pain of different origins and, consequently, different management requirements.

Renal dysfunction in routine proton-pump inhibitor use may be linked to comorbidities: A real-world observational study

INTRODUCTION

The use of proton-pump inhibitors (PPI) is linked with infrequent but serious adverse events, including acute kidney injury, chronic kidney disease (CKD) and progression of CKD. Data on renal safety in routine use of PPI are more relevant to clinical practice. We studied whether such use of PPI is associated with renal dysfunction.

METHODS

Patients taking PPI for at least six weeks had serum creatinine tested pre (n = 200) and post (n = 180) recruitment. These patients were then advised to follow-up: those taking PPI for at least 90 days in the next six months (n = 77) and at least another 90 days in the following six months (n = 50), had serum creatinine tested at such follow-up. Renal dysfunction was defined as any increase in serum creatinine level above baseline.

RESULTS

The 200 patients recruited had mean age 39.6 (SD 9.2) years. Ninety-eight (49%) patients had a history of previous PPI use (median six months; interquartile range [IQR] 3-24). Only 20 (11.1%) patients at six weeks, 11 (14.3%) at six months and six (12%) at one year had increase in creatinine level; a majority of them had less than 0.3 mg/dL increase. Ten of these 20 (six weeks), five of 11 (six months) and five of six (one year) had other risk factors for renal dysfunction. No patient developed CKD during the study period.

CONCLUSIONS

Mild and non-progressive increase in serum creatinine occurred in 10% to 15% of patients on routine PPI use. A majority of them had other risk factors. Small sample size and short follow-up duration are a few limitations of this study.

Diagnosis and management of autoimmune diseases in the ICU

Autoimmune diseases encompass a broad spectrum of disorders characterized by disturbed immunoregulation leading to the development of specific autoantibodies, resulting in inflammation and multiple organ involvement. A distinction should be made between connective tissue diseases (mainly systemic lupus erythematosus, systemic scleroderma, inflammatory muscle diseases, and rheumatoid arthritis) and vasculitides (mainly small-vessel vasculitis such as antineutrophil cytoplasmic antibody-associated vasculitis and immune-complex mediated vasculitis). Admission of patients with autoimmune diseases to the intensive care unit (ICU) is often triggered by disease flare-ups, infections, and organ failure and is associated with high mortality rates. Management of these patients is complex, including prompt disease identification, immunosuppressive treatment initiation, and life-sustaining therapies, and requires multi-disciplinary involvement. Data about autoimmune diseases in the ICU are limited and there is a need for multicenter, international collaboration to improve patients' diagnosis, management, and outcomes. The objective of this narrative review is to summarize the epidemiology, clinical features, and selected management of severe systemic autoimmune diseases.

The role of platelets in immune-mediated inflammatory diseases

Immune-mediated inflammatory diseases (IMIDs) are characterized by excessive and uncontrolled inflammation and thrombosis, both of which are responsible for organ damage, morbidity and death. Platelets have long been known for their role in primary haemostasis, but they are now also considered to be components of the immune system and to have a central role in the pathogenesis of IMIDs. In patients with IMIDs, platelets are activated by disease-specific factors, and their activation often reflects disease activity. Here we summarize the evidence showing that activated platelets have an active role in the pathogenesis and the progression of IMIDs. Activated platelets produce soluble factors and directly interact with immune cells, thereby promoting an inflammatory phenotype. Furthermore, platelets participate in tissue injury and promote abnormal tissue healing, leading to fibrosis. Targeting platelet activation and targeting the interaction of platelets with the immune system are novel and promising therapeutic strategies in IMIDs.

Targeting plasma cells in systemic autoimmune rheumatic diseases - Promises and pitfalls

Plasma cells are the antibody secretors of the immune system. Continuous antibody secretion over years can provide long-term immune protection but could also be held responsible for long-lasting autoimmunity in case of self-reactive plasma cells. Systemic autoimmune rheumatic diseases (ARD) affect multiple organ systems and are associated with a plethora of different autoantibodies. Two prototypic systemic ARDs are systemic lupus erythematosus (SLE) and Sjögren's disease (SjD). Both diseases are characterized by B-cell hyperactivity and the production of autoantibodies against nuclear antigens. Analogues to other immune cells, different subsets of plasma cells have been described. Plasma cell subsets are often defined dependent on their current state of maturation, that also depend on the precursor B-cell subset from which they derived. But, a universal definition of plasma cell subsets is not available so far. Furthermore, the ability for long-term survival and effector functions may differ, potentially in a disease-specific manner. Characterization of plasma cell subsets and their specificity in individual patients can help to choose a suitable targeting approach for either a broad or more selective plasma cell depletion. Targeting plasma cells in systemic ARDs is currently challenging because of side effects or varying depletion efficacies in the tissue. Recent developments, however, like antigen-specific targeting and CAR-T-cell therapy might open up major benefits for patients beyond current treatment options.

Abnormally high expression of D1-like dopamine receptors on lupus CD4+ T cells promotes Tfh cell differentiation

OBJECTIVE

SLE is a chronic autoimmune disease that places a great burden on human society. T follicular helper (Tfh) cells play a critical role in the pathological process of SLE. Therefore, elucidating the mechanism of Tfh cell differentiation will contribute to SLE treatment. Dopamine receptors (DRDs) are members of the family of G protein-coupled receptors and are primarily divided into D1-like and D2-like receptors. Previous studies have found that DRDs can regulate differentiation of immune cells. However, there is currently a lack of research on DRDs and Tfh cells. We here explore the relationship between DRDs and Tfh cells, and analyse the relationship between DRD expression on Tfh cells and the course of SLE.

METHODS

We first detected plasma catecholamine concentrations in patients with SLE and healthy controls by mass spectrometry, followed by reverse transcription-quantitative PCR (RT-qPCR) to detect DRD messenger RNA (mRNA) expression in peripheral blood mononuclear cells (PBMCs) and CD4+ T cells, and flow cytometry to detect DRD expression in Tfh cells. Finally, in vitro experiments and RNA sequencing (RNA-seq) were used to explore the possible pathway by which DRDs regulate Tfh cell differentiation.

RESULTS

The plasma dopamine concentration in patients with SLE was significantly increased, and abnormal mRNA expression of DRDs was observed in both PBMCs and CD4+ T cells. The results of flow cytometry showed that D1-like receptors were highly expressed in Tfh cells of patients with SLE and associated with disease activity. In vitro induction experiments showed that differentiation of naïve T cells into Tfh cells was accompanied by an increase in D1-like receptor expression. RNA-seq and RT-qPCR results indicate that D1-like receptors might promote Tfh cell differentiation through the Phosphatidylinositol3-kinase (PI3K)/protein kinase B (AKT)/Forkhead box protein O1 (FOXO1)/Kruppel-like factor 2 (Klf2) pathway.

CONCLUSION

Tfh cells in patients with SLE highly express D1-like receptors, which correlate with disease activity. D1-like receptors may promote Tfh cell differentiation through the PI3K/AKT/FOXO1/Klf2 pathway.

Dose adjustment of rheumatology and allergy/immunology medications in chronic kidney disease: awareness and knowledge among internal medicine housestaff

Background

Patients with chronic kidney disease (CKD) are at increased risk for adverse drug events due to medication dosing errors. We studied the awareness and knowledge among internal medicine housestaff (IMHS) of proper dose adjustment of commonly used rheumatology and allergy/immunology medications for patients with CKD.

Methods

We surveyed 353 IMHS to evaluate their awareness of the need for medication dose adjustments for patients with CKD and knowledge for medication adjustment by level of glomerular filtration rate for common rheumatology and allergy/immunology medications.

Results

There was lack of awareness and knowledge for both rheumatology and allergy/immunology medications. Incorrect awareness and knowledge were as follows: allopurinol, 21.2%, 73.4%; colchicine, 19.0%, 75.9%; diphenhydramine, 34.0%, 34.0%; loratadine, 82.2%, 93.2%; and montelukast, 34.0%, 34.0%, respectively. Exploratory logistic regression analyses showed that PGY1 residents had higher odds for lack of awareness for allopurinol (odds ratio [OR] 24.57, 95% CI [confidence interval] 4.69, 99.13, P < 0.001), colchicine (OR 3.98, 95% CI 1.50, 10.51, P < 0.01), diphenhydramine (OR 2.24, 95% CI 1.10, 4.54, P < 0.04), and montelukast (OR 2.45, 95% CI 1.20, 5.00, P < 0.05) than PGY3 residents. A nephrology rotation in medical school was associated with lower odds for incorrect knowledge for allopurinol (OR 0.46, 95% CI 0.25, 0.87, P < 0.05) and montelukast (OR 0.50, 95% CI 0.27, 0.92, P < 0.05).

Conclusion

Overall, awareness and knowledge were poor among IMHS for dose adjustments of rheumatology and allergy/immunology medications in patients with CKD. Proper education and exposure to nephrology during training may improve quality and safety of care for patients with CKD.

Comparative physiological anthropogeny: exploring molecular underpinnings of distinctly human phenotypes

Anthropogeny is a classic term encompassing transdisciplinary investigations of the origins of the human species. Comparative anthropogeny is a systematic comparison of humans and other living nonhuman hominids (so-called "great apes"), aiming to identify distinctly human features in health and disease, with the overall goal of explaining human origins. We begin with a historical perspective, briefly describing how the field progressed from the earliest evolutionary insights to the current emphasis on in-depth molecular and genomic investigations of "human-specific" biology and an increased appreciation for cultural impacts on human biology. While many such genetic differences between humans and other hominids have been revealed over the last two decades, this information remains insufficient to explain the most distinctive phenotypic traits distinguishing humans from other living hominids. Here we undertake a complementary approach of "comparative physiological anthropogeny," along the lines of the preclinical medical curriculum, i.e., beginning with anatomy and considering each physiological system and in each case considering genetic and molecular components that are relevant. What is ultimately needed is a systematic comparative approach at all levels from molecular to physiological to sociocultural, building networks of related information, drawing inferences, and generating testable hypotheses. The concluding section will touch on distinctive considerations in the study of human evolution, including the importance of gene-culture interactions.

Evaluation of renal markers in systemic autoimmune diseases

Renal involvement is a common occurrence in subjects with systemic autoimmune diseases. The renal manifestation and its severity depend on the underlying condition and may reversely complicate the clinical course of autoimmune diseases. Renal function markers have been widely used in the assessment of normal functioning of kidneys including glomerular filtration rate and concentrating and diluting capacity of the kidney. An increase or decrease in the values of these markers may indicate kidney dysfunction. In this study, a number of critical renal markers were examined in seropositive autoimmune diseases including systemic lupus erythematosus (SLE), connective tissue disorder (CTD), and rheumatoid arthritis (RA). The data from three cohorts of subjects enrolled in renal markers and autoimmune antibody testing between January 2015 to August 2019 were retrospectively studied. The prevalence of renal markers that were out of the reference range and their average levels in female and male subgroups across SLE, CTD, and RA cohorts were compared and analyzed. The levels of renal markers are significantly affected by the presence of autoantibodies, in particular eGFR, cystatin C, and albumin. Autoantibodies were also more frequent in subjects with severe renal function damage. Close follow-up of both renal markers and autoantibodies may potentially assist in the early diagnosis of kidney diseases and improve the survival and life expectancy of autoimmune patients.

Challenging diagnosis of renal failure associated with severe neurological symptoms in a patient with mixed connective tissue disease

We report the case of a patient followed for a mixed connective tissue disease with signs of systemic sclerosis and systemic lupus, who presented an acute renal failure with severe neurological symptoms (confusion, obnubilation) and hypertension. The distinction between scleroderma renal crisis and lupus nephritis was challenging and hence, the decision to use or not high dose of corticosteroids. Kidney biopsy was of major importance for the diagnosis and therapeutic strategy. The diagnosis of neurological symptoms was also made difficult given the clinical presentation and the results of imaging. Neurolupus, malignant hypertension, or posterior reversible encephalopathy syndrome were the evoked diagnosis.

Nephrotic Syndrome as an Extramuscular Manifestation of Anti-EJ Antibody-Positive Dermatomyositis: A Case Report and Review of the Literature

Renal involvement is underestimated as an extramuscular manifestation of dermatomyositis (DM). Here, we describe a 67-year-old woman with anti-glycyl-transfer ribonucleic acid synthetase (anti-EJ) antibody and anti-ribonucleoprotein antibody-positive DM complicated by systemic sclerosis, who developed nephrotic syndrome concurrently with the exacerbation of DM, as indicated by incremental serum creatine kinase levels, high-intensity lesions on muscle magnetic resonance imaging, and active interstitial pneumonitis on chest computed tomography. Renal biopsy revealed the presence of immune-deposition in the glomerulus by immunofluorescence. To our knowledge, this is the first report describing the coexistence of anti-EJ antibody-positive DM and nephrotic syndrome. More reports of similar cases are warranted to substantiate the association.

Association of HLA-DR1, HLA-DR13, and HLA-DR16 Polymorphisms with Systemic Lupus Erythematosus: A Meta-Analysis

Objectives

The principal purpose of this meta-analysis was to assess the association between HLA-DRB1 (HLA-DR1, HLA-DR13, and HLA-DR16) polymorphisms and SLE susceptibility.

Methods

We searched published case-control studies on the association between HLA-DRB1 polymorphisms and SLE susceptibility from PubMed and Web of Science databases. The pooled ORs with 95% CIs were utilized to estimate the strength of association of HLA-DR1, HLA-DR13, and HLA-DR16 polymorphisms and SLE susceptibility by fixed effect models. We also performed sensitivity analysis, trial sequential analysis, Begg's test, and Egg's test in this meta-analysis.

Results

A total of 18 studies were included in this meta-analysis. Overall analysis showed that HLA-DR1 and HLA-DR13 polymorphisms were associated with a decreased risk of SLE (OR = 0.76, 95% CI: 0.65-0.90, P < 0.01; OR = 0.58, 95% CI: 0.50-0.68, P < 0.01), and HLA-DR16 polymorphism was associated with an increased risk of SLE (OR = 1.70, 95% CI: 1.24-2.33, P < 0.01). In subgroup analysis of ethnicity, the results were as follows: HLA-DR1 polymorphism in Caucasians (OR = 0.76, 95% CI: 0.58-0.98,P = 0.04) and North Americans (OR = 0.64, 95% CI: 0.42-0.96,P = 0.03); HLA-DR13 polymorphism in Caucasians (OR = 0.62, 95% CI: 0.47-0.82,P < 0.01) and East Asians (OR = 0.44, 95% CI: 0.34-0.57,P < 0.01); and HLA-DR16 polymorphism in East Asians (OR = 2.62, 95% CI: 1.71-4.03,P < 0.01).

Conclusions

This meta-analysis showed that HLA-DR1 and HLA-DR13 are protective factors for SLE, and HLA-DR16 is a risk factor. Due to the limitations of this meta-analysis, the association between HLA-DRB1 polymorphisms and SLE susceptibility needs to be further researched before definitive conclusions are proved.

Assessing and counteracting fibrosis is a cornerstone of the treatment of CKD secondary to systemic and renal limited autoimmune disorders

Chronic kidney disease (CKD) is an increasing cause of morbidity and mortality worldwide. Besides the higher prevalence of diabetes, hypertension and aging worldwide, immune mediated disorders remain an important cause of kidney disease and are especially prevalent in young adults. Regardless of the initial insult, final pathway to CKD and kidney failure is always the loss of normal tissue and fibrosis development, in which the dynamic equilibrium between extracellular matrix synthesis and degradation is disturbed, leading to excessive production and accumulation. During fibrosis, a multitude of cell types intervene at different levels, but myofibroblasts and inflammatory cells are considered critical in the process. They exert their effects through different molecular pathways, of which transforming growth factor β (TGF-β) has demonstrated to be of particular importance. Additionally, CKD itself promotes fibrosis due to the accumulation of toxins and hormonal changes, and proteinuria is simultaneously a manifestation of CKD and a specific driver of renal fibrosis. Pathways involved in renal fibrosis and CKD are closely interrelated, and although important advances have been made in our knowledge of them, it is still necessary to translate them into clinical practice. Given the complexity of this process, it is highly likely that its treatment will require a multi-target strategy to control the origin of the damage but also the mechanisms that perpetuate it. Fortunately, rapid technology development over the last years and new available drugs in the nephrologist's armamentarium give reasons for optimism that more personalized assistance for CKD and renal fibrosis will appear in the future.

Cutaneous manifestations of acute kidney injury

Acute kidney injury (AKI) is a common medical problem with a multitude of aetiologies. Prompt diagnosis and management is key in the prevention of complications. Cutaneous signs can often give diagnostic clues of underlying systemic diseases causing AKI.

This review summarises cutaneous findings of diseases causing AKI in adults. Knowledge of such cutaneous signs could lead to earlier diagnosis of underlying kidney disease and facilitate management strategies in a timely manner.

Acute interstitial nephritis, polyarteritis nodosa, Kawasaki's disease, granulomatosis with polyangiitis (previously Wegener's granulomatosis), microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (previously Churg-Strauss syndrome), Henoch-Schonlein purpura, cryoglobulinaemia, Sjogren's Syndrome, systemic sclerosis, nephrogenic systemic fibrosis, dermatomyositis, systemic lupus erythematosus, amyloidosis, and cholesterol embolisation syndrome were highlighted as diseases causing AKI with cutaneous manifestations.

Rheumatoid arthritis: Extra-articular manifestations and comorbidities

Although synovitis is the pathological hallmark of rheumatoid arthritis (RA), many extra-articular manifestations (EMs) and comorbidities likely occur due to the complex, chronic, inflammatory, and autoimmune features of RA. Cardiovascular (CV) disease is the most common cause of death in patients with RA. Compared to the general population, patients with RA have twice the risk of myocardial infarction and up to 50% increased CV mortality risk. Severe and prolonged disease activity, genetics, and inflammation (e.g. CRP, ACPA, cytokines, matrix-degrading enzymes) play important roles in CV disease and atheroscleroticdamage. The second major cause of death in patients with RA is respiratory disease, which occurs in 30-40% of patients. RA may affect the lung interstitium, airways, and pleurae, while pulmonary vascular involvement is less frequent. Central and peripheral nervous system involvement is usually due to small vessel vasculitis, joint damage, or drug toxicity. There is also evidence that microvascular cerebral damage caused by systemic inflammation is associated with the development of Alzheimer's disease and vascular dementia. Some observational studies have hinted how Disease Modified Anti-Rheumatic Drugs and biologics could reduce the incidence of dementia. Primary gastrointestinal and renal involvements are rare and often relate to drug therapy. To minimize morbidity and mortality, physicians must manage RA disease activity (treat-to-target) and monitor risk factors and concomitant conditions (e.g. smoking cessation; weight regulation; monitoring blood pressure, lipids, thyroid hormone, folic acid and homocysteine; screening for depression, anxiety, atlantoaxial instability, and atherosclerosis). This article aims to provide an overview of the most prevalent and important EMs and comorbidities associated with RA.

Artemisinin analogue SM934 protects against lupus-associated antiphospholipid syndrome via activation of Nrf2 and its targets

Kidney is a major target organ in both antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). The etiology of antiphospholipid syndrome nephropathy associated lupus nephritis (APSN-LN) is intricate and remains largely unrevealed. We proposed in present work, that generation of antiphospholipid antibodies (aPLs), especially those directed towards the oxidized neoepitopes, are largely linked with the redox status along with disease progression. Moreover, we observed that compromised antioxidative capacity coincided with turbulence of inflammatory cytokine profile in the kidney of male NZW×BXSB F1 mice suffered from APSN-LN. SM934 is an artemisinin derivative that has been proved to have potent immunosuppressive properties. In current study, we elaborated the therapeutic benefits of SM934 in male NZW×BXSB F1 mice, a murine model develops syndrome resembled human APS associated with SLE, for the first time. SM934 treatment comprehensively impeded autoantibodies production, inflammatory cytokine accumulation and excessive oxidative stress in kidney. Among others, we interpreted in present work that both anti-inflammatory and antioxidative effects of SM934 is closely correlated with the enhancement of Nrf2 signaling and expression of its targets. Collectively, our finding confirmed that therapeutic strategy simultaneously exerting antioxidant and anti-inflammatory efficacy provide a novel feasible remedy for treating APSN-LN.

Staphylococcus-associated acute glomerulonephritis in a patient with dermatomyositis

Staphylococcus-associated glomerulonephritis (SAGN) occurs as a complication of staphylococcal infection elsewhere in the body. Dermatomyositis (DM) can be associated with glomerulonephritis due to the disease per se. We report a case of a 40-year-old male patient with DM who presented with acute kidney injury, and was initially pulsed with methylprednisolone for 3 days, followed by dexamethasone equivalent to 1 mg/kg/day prednisolone. He was subsequently found to have SAGN on kidney biopsy along with staphylococcus bacteraemia and left knee septic arthritis. With proof of definitive infection, intravenous immunoglobulin 2 g/kg over 2 days was given and steroids were reduced. He was treated with intravenous vancomycin. With treatment, the general condition of the patient improved. On day 38, he developed infective endocarditis and died of congestive heart failure subsequently. Undiagnosed staphylococcal sepsis complicating a rheumatological disease course can lead to complications like SAGN, infective endocarditis and contribute to increased morbidity and mortality, as is exemplified by our case.

Exploring the knowledge gap of immune checkpoint inhibitors in chronic renal failure: A systematic review of the literature

Targeting the immune system with immune checkpoint inhibitors (ICI) to treat cancer has been lately adopted with a significant improvement of patients' survival. In parallel, the incidence of malignancy in chronic kidney disease (CKD) patients is increasing, but solid evidence concerning the efficacy and safety of ICI in this population is lacking. Moreover, the use of these agents as immunity boosters in kidney graft recipients treated with immunosuppressors is still controversial. We present in this article a review of the pharmacological properties of these drugs and their behavior with kidney failure and dialysis, as well as evidence of their use in different populations of CKD. Most of the available data are limited to case reports and case series. These drugs appear to be safe without dose adjustment in CKD patients and patients on dialysis. A major concern with this therapy in transplanted patients remains the risk of graft rejection.

Autoimmune Connective Tissue Disease Following Carbon Monoxide Poisoning: A Nationwide Population-Based Cohort Study

Background

In addition to hypoxia, oxidative stress and inflammation due to carbon monoxide (CO) poisoning cause adverse health effects. These mechanisms are related to the occurrence of autoimmune connective tissue disease, but studies on the association between CO poisoning and autoimmune connective tissue disease are limited. We conducted a study to evaluate the occurrence of autoimmune connective tissue disease following CO poisoning.

Methods

We identified participants with CO poisoning diagnosed between 1999 and 2012 from the Nationwide Poisoning Database and selected participants without CO poisoning from the Taiwan National Health Insurance Research Database with matching age and index dates at a 1:3 ratio. Sex, underlying comorbidities, and monthly income were also included in the analyses. We followed up the participants until 2013 and made comparison of the risk of autoimmune connective tissue disease between participants with and without CO poisoning.

Results

The 23,877 participants with CO poisoning had a higher risk for autoimmune connective tissue disease than the 71,631 participants without CO poisoning (adjusted hazard ratio [AHR], 3.5; 95% confidence interval [CI], 3.1–3.9) after adjustment for sex, diabetes, Lyme disease, herpes zoster, infectious mononucleosis, hepatitis, HIV infection, liver disease, renal disease, non-CO poisoning or drug abuse, malignancy, hypertension, hyperlipidemia, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and monthly income. An increased risk was observed even after 4 years of follow-up (AHR, 3.6; 95% CI, 3.0–4.4).

Conclusion

The risk of autoimmune connective tissue disease increased following CO poisoning. Close follow-up of the patients with CO poisoning for the development of connective tissue disease is recommended, and further investigation of the detailed mechanisms is warranted.

Systemic Lupus Erythematosus Treatment in Pregnancy: Case Study

Systemic lupus erythematosus is a chronic inflammatory autoimmune disease with high prevalence in female in reproductive age. In recent years the prognosis of pregnant patients with SLE has improved significantly. Even though the treatment options have improved, the risk of flares, preeclampsia, pregnancy loss, and premature labours remains high compared to healthy women. The aim of this article is to offer a review of current treatment options in pregnant patients with SLE and to present a case report of 32-year-old patient with newly diagnosed acute outbreak of SLE, who experienced a life-threatening multisystem flare at 24 weeks of gestational age. This case represents one of the most extreme manifestations of lupus disease activity associated with pregnancy that has been reported in literature and emphasizes the importance of preconception evaluation and counseling and amultidisciplinary management approach in cases with a complex and evolving clinical course.

Urinary Metals Concentrations and Biomarkers of Autoimmunity among Navajo and Nicaraguan Men

Metals are suspected contributors of autoimmune disease among indigenous Americans. However, the association between metals exposure and biomarkers of autoimmunity is under-studied. In Nicaragua, environmental exposure to metals is also largely unexamined with regard to autoimmunity. We analyzed pooled and stratified exposure and outcome data from Navajo (n = 68) and Nicaraguan (n = 47) men of similar age and health status in order to characterize urinary concentrations of metals, compare concentrations with the US National Health and Nutrition Examination Survey (NHANES) male population, and examine the associations with biomarkers of autoimmunity. Urine samples were analyzed for metals via inductively coupled plasma mass spectrometry (ICP-MS) at the US Centers for Disease Control and Prevention. Serum samples were examined for antinuclear antibodies (ANA) at 1:160 and 1:40 dilutions, using an indirect immunofluorescence assay and for specific autoantibodies using enzyme-linked immunosorbent assay (ELISA). Logistic regression analyses evaluated associations of urinary metals with autoimmune biomarkers, adjusted for group (Navajo or Nicaraguan), age, and seafood consumption. The Nicaraguan men had higher urinary metal concentrations compared with both NHANES and the Navajo for most metals; however, tin was highest among the Navajo, and uranium was much higher in both populations compared with NHANES. Upper tertile associations with ANA positivity at the 1:160 dilution were observed for barium, cesium, lead, strontium and tungsten.

Renal Involvement in Systemic Sclerosis: An Update

BACKGROUND

Systemic sclerosis is an immune-mediated rheumatic disease characterized by vascular abnormalities, tissue fibrosis and autoimmune phenomena.

SUMMARY

Renal disease occurring in patients with systemic sclerosis may have a variable clinicopathological picture. The most specific renal condition associated with systemic sclerosis is scleroderma renal crisis, characterized by acute onset of renal failure and severe hypertension. Although the management of scleroderma renal crisis was revolutionized by the introduction of angiotensin-converting enzyme inhibitors, there is still a significant proportion of patients with poor outcomes. Therefore, research on establishing disease markers (clinical, ultrasonographical and serological) and clear diagnostic criteria, which could limit the risk of developing scleroderma renal crisis and facilitate diagnosis of this complication, is ongoing. Other forms of renal involvement in systemic sclerosis include vasculitis, an isolated reduced glomerular filtration rate in systemic sclerosis, antiphospholipid-associated nephropathy, high intrarenal arterial stiffness and proteinuria. Key Messages: Scleroderma renal crisis is the most specific and life-threatening renal presentation of systemic sclerosis, albeit with declining prevalence. In patients with scleroderma renal crisis, it is mandatory to control blood pressure early with increasing doses of angiotensin-converting enzyme inhibitors, along with other antihypertensive drugs if necessary. There is a strong association between renal involvement and patients' outcomes in systemic sclerosis; consequently, it becomes mandatory to find markers that may be used to identify patients with an especially high risk of scleroderma renal crisis.

Metabolic Disturbances in Urinary and Plasma Samples from Seven Different Systemic Autoimmune Diseases Detected by HPLC-ESI-QTOF-MS

Systemic autoimmune diseases (SADs) are characterized by dysfunctioning of the immune system, which causes damage in several tissues and organs. Among these pathologies are systemic lupus erythematosus (SLE), systemic sclerosis or scleroderma, Sjögren's syndrome, rheumatoid arthritis, primary antiphospholipid syndrome (PAPS), mixed connective tissue disease (MCTD), and undifferentiated connective tissue disease (UCTD). Early diagnosis is difficult due to similarity in symptoms, signs, and clinical test results. Hence, our aim was to search for differentiating metabolites of these diseases in plasma and urine samples. We performed metabolomic profiling by liquid chromatography-mass spectrometry (LC-MS) of samples from 228 SADs patients and 55 healthy volunteers. Multivariate PLS models were applied to investigate classification accuracies and identify metabolites differentiating SADs and healthy controls. Furthermore, we specifically investigated UCTD against the other SADs. PLS models were able to classify most SADs vs healthy controls (area under the roc curve (AUC) > 0.7), with the exception of MCTD and PAPS. Differentiating metabolites consisted predominantly of unsaturated fatty acids, acylglycines, acylcarnitines, and amino acids. In accordance with the difficulties in defining UCTD, the UCTD metabolome did not differentiate well from the other SADs. However, most UCTD cases were classified as SLE, suggesting that metabolomics may provide a tool to reassess UCTD diagnosis into other conditions for more well-informed therapeutic strategies.

Ocular Manifestations in Rheumatoid Arthritis, Connective Tissue Disease, and Vasculitis: A Systematic Review and Metaanalysis

Objective.

Rheumatoid arthritis (RA) and other rheumatic diseases may present with ocular manifestations.

The purpose of our work was to determine the prevalence and type of eye involvement in RA and other connective tissue diseases through a metaanalysis and literature review.

Methods.

A systematic review of the literature was performed using Medline, Web of Science, and the Cochrane Library from their inceptions until January 7, 2019. Conjunctivitis, keratoconjunctivitis sicca, xeropthalmia, uveitis, eye hemorrhage, optic neuritis, papilledema, orbital disease, retinal artery/vein occlusion, macular edema, retinitis, chorioretinitis, scleritis, iridocyclitits, choroid hemorrhage, blindness, and amaurosis fugax were searched for prevalence in patients with RA, systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), dermatomyositis, polymyositis, systemic sclerosis, Sjögren syndrome (SS), undifferentiated connective tissue disease, giant cell arteritis, granulomatosis polyangiitis (GPA; formerly Wegener granulomatosis), systemic vasculitis, and sarcoidosis.

Results.

There were 3394 studies identified and 65 included. The prevalence of eye involvement was 18% in RA, 26% in GPA, 27% in giant cell arteritis, 27% in sarcoidosis, 31% in SLE, and 35% in APS. The most common manifestation was dry eye syndrome (“dry eye”; keratoconjunctivitis sicca) in most diseases analyzed, with an especially high frequency of 89% in SS. Anterior and posterior uveitis were the most common ocular complications in sarcoidosis, occurring in 16% (95% CI 3–28) and 6% (95% CI 3–9) of patients, respectively.

Conclusion.

Eye involvement is present in approximately one-fifth of patients with RA, and a one-quarter to one-third of patients with connective tissue diseases (other than SS at 89%) and vasculitis.

A case report of Sjögren's syndrome associated with protein-losing gastroenteropathy successfully treated with methylprednisolone

Protein-losing gastroenteropathy (PLGE) is a rare manifestation of primary Sjögren’s syndrome that is most commonly reported in Japan. Herein, the case of a 71-year-old Chinese male patient, diagnosed with PLGE and Sjögren’s syndrome, is reported. The patient presented with peripheral oedema, and PLGE was diagnosed based on the result of technetium-99m (^99mTc)-labelled albumin scintigraphy. In addition to a positive Schirmer’s test, the patient had atrophy of the salivary gland with lymphocyte infiltration, impaired parotid-gland secretory and excretory function, and an increased level of anti-SSA antibodies, fulfilling the criteria for Sjögren’s syndrome. He was successfully treated with methylprednisolone. Follow-up ^99mTc-labelled albumin scintigraphy results correlated well with clinical improvement and increased serum albumin levels. The present case study highlights the necessity of considering a diagnosis of protein loss enteropathy associated with primary Sjögren’s syndrome when patients have unexplained hypoproteinaemia.

Primary IgA Vasculitis with Nephritis in a Patient with Rheumatoid Arthritis Diagnosed by Anti-galactose-deficient IgA1 Immunostaining

Renal disease is a common complication of rheumatoid arthritis (RA) and can occur secondary to RA or be induced by therapeutic agents. Recently, glomerular deposition of galactose-deficient IgA1 (Gd-IgA1) was identified as a feature of primary IgA vasculitis with nephritis (IgA-VN). We herein report a case of IgA-VN in an RA patient whose disease activity was controlled by treatment with etanercept. To distinguish between primary IgA-VN and secondary IgA-VN caused by RA or etanercept, we performed immunostaining of renal biopsy sections with the Gd-IgA1-specific antibody KM55. Positive KM55 staining confirmed the diagnosis of primary IgA-VN in a patient with RA.

Membranous nephropathy caused by rheumatoid arthritis

Membranous nephropathy (MN) caused by disease-modifying antirheumatic drugs is relatively common in patients with rheumatoid arthritis (RA). However, MN rarely occurs due to RA itself. We describe a 61-year-old woman with RA who showed nephrotic syndrome. She was admitted because of systemic edema and severe arthritis. She had a long history of RA successfully treated with methotrexate (MTX), but discontinued all treatments 4 years before hospitalization. She had never been treated with bucillamine or gold. Laboratory test results were positive for anti-cyclic citrullinated peptide antibody and negative for anti-nuclear antibody. Renal pathologic findings were compatible with MN. Immunofluorescence microscopy showed IgG, IgA, κ, λ, and C3 along the glomerular capillary wall, whereas deposition of IgM or C1q was not detected. In terms of the IgG subclasses, only IgG2 findings were positive. Results for glomerular antigen and serum antibody for M-type phospholipase A2 receptor and thrombospondin type 1 domain-containing 7A were negative. HLA type did not include the HLA-DQA1 gene that is a concern in primary MN (PMN). She responded to intensive immunosuppressive therapy consisting of prednisolone, tacrolimus, and MTX with a parallel reduction of proteinuria. Based on assessments for differentiating PMN from secondary MN (SMN), the diagnosis of the present case was incompatible with PMN. Taken together, we consider that SMN in the present case was due to RA itself rather than drug-induced MN.

Refractory lupus nephritis: When, why and how to treat

Refractory lupus nephritis indicates an inadequate response to lupus nephritis therapy. It implies persisting or worsening disease activity despite therapy, but the definition is complicated by the parameters of response, proteinuria and renal function, that do not discriminate clearly between activity and irreversible damage. Understanding the causes of refractory disease and developing treatment strategies is important because these patients are more likely to develop poor outcomes, especially end stage renal disease. This review explores current concepts and definitions of refractory disease and summarises treatment approaches that have been used in observational cohort studies and case series. We highlight the importance of optimising adherence to the prescribed immunosuppressive and supportive measures and avoidance of diagnostic delay. Treatment options include higher dose glucocorticoid, switching between cyclophosphamide and mycophenolate acid derivates, or addition of rituximab, the latter potentially in combination with belimumab. Less evidence supports extracorporeal treatment (plasma exchange or immunoadsorption), calcineurin inhibitors (cyclosporine A or tacrolimus), intravenous immunoglobulin and stem cell transplantation. Improvements in understanding what refractory disease is and how definitions can be integrated into treatment pathways has the potential to enhance lupus nephritis outcomes.

Adrenal insufficiency in systematic lupus erythematosus (SLE) and antiphospholipid syndrome (APS): A systematic review

BACKGROUND

Adrenal insufficiency (AI) is associated with high morbidity and mortality. The aim of this systematic review was to enhance diagnostic approaches and summarize therapeutic strategies in the management of AI in patients with systematic lupus erythematosus (SLE) or antiphospholipid syndrome (APS).

METHODS

A literature search of PubMed and Medline databases was performed and 91 publications containing 105 cases were included for the final analysis.

RESULTS

The following frequency of clinical signs and symptoms was noted: abdominal pain (39.04%) was the leading symptom, followed by fever (33.33%), vomiting (23.81%), and nausea (19.05%). APS was present in 73%, SLE in 17% of the patients, while 2% had a diagnosis of both, SLE and APS. ACTH stimulation test (ACTHst) was performed in 18% of cases and 76.6% of them were unresponsive towards stimulation. Variable treatment approaches were used: hydrocortisone was most commonly used (38.09%), followed by fludrocortisone (26.67%), prednisolone (20.00%) and volume replacement treatment (11.43%), respectively.

CONCLUSIONS

This analysis highlights the importance of an early diagnosis and initiation of therapeutic management when AI is suspected. In line, signs and symptoms related to autoimmune diseases in patients with AI should be reviewed crtitically.

Impact of Inflammation on Ferritin, Hepcidin and the Management of Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a major problem in chronic kidney disease (CKD), causing increased mortality. Ferritin stores iron, representing iron status. Hepcidin binds to ferroportin, thereby inhibiting iron absorption/efflux. Inflammation in CKD increases ferritin and hepcidin independent of iron status, which reduce iron availability. While intravenous iron therapy (IIT) is superior to oral iron therapy (OIT) in CKD patients with inflammation, OIT is as effective as IIT in those without. Inflammation reduces predictive values of ferritin and hepcidin for iron status and responsiveness to iron therapy. Upper limit of ferritin to predict iron overload is higher in CKD patients with inflammation than in those without. However, magnetic resonance imaging studies show lower cutoff levels of serum ferritin to predict iron overload in dialysis patients with apparent inflammation than upper limit of ferritin proposed by international guidelines. Compared to CKD patients with inflammation, optimal ferritin levels for IDA are lower in those without, requiring reduced iron dose and leading to decreased mortality. The management of IDA should differ between CKD patients with and without inflammation and include minimization of inflammation. Further studies are needed to determine the impact of inflammation on ferritin, hepcidin and therapeutic strategy for IDA in CKD.

Sex differences in pulmonary arterial hypertension: role of infection and autoimmunity in the pathogenesis of disease

Registry data worldwide indicate an overall female predominance for pulmonary arterial hypertension (PAH) of 2–4 over men. Genetic predisposition accounts for only 1–5% of PAH cases, while autoimmune diseases and infections are closely linked to PAH. Idiopathic PAH may include patients with undiagnosed autoimmune diseases based on the relatively high presence of autoantibodies in this group. The two largest PAH registries to date report a sex ratio for autoimmune connective tissue disease-associated PAH of 9:1 female to male, highlighting the need for future studies to analyze subgroup data according to sex. Autoimmune diseases that have been associated with PAH include female-dominant systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, and thyroiditis as well as male-dominant autoimmune diseases like myocarditis which has been linked to HIV-associated PAH. The sex-specific association of PAH to certain infections and autoimmune diseases suggests that sex hormones and inflammation may play an important role in driving the pathogenesis of disease. However, there is a paucity of data on sex differences in inflammation in PAH, and more research is needed to better understand the pathogenesis underlying PAH in men and women. This review uses data on sex differences in PAH and PAH-associated autoimmune diseases from registries to provide insight into the pathogenesis of disease.

Early Renin-angiotensin System Blockade Improved Short-term and Longterm Renal Outcomes in Systemic Lupus Erythematosus Patients with Antiphospholipid-associated Nephropathy

Objective.

To investigate the renal protective effects of early renin-angiotensin-aldosterone system (RAAS) blockade with renin-angiotensin system inhibitors (RASI) in systemic lupus erythematosus (SLE) patients with antiphospholipid-associated nephropathy (aPLN).

Methods.

Medical data of 57 SLE patients with biopsy-proven aPLN were analyzed. Early RAAS blockade was defined as administration of RASI within 3 months after kidney biopsy and continued for ≥ 12 months.

Results.

There was no significant difference in demographic data, laboratory findings, and renal histology by the time of kidney biopsy, except that the RASI group had higher proteinuria levels vs the non-RASI group [5.2 (2.8–8.8) vs 1.9 (0.6–2.8) g/d, p = 0.005, respectively] and higher prevalence of hypertension (75% vs 29%, p = 0.001, respectively). No significant difference between the 2 groups was observed in estimated glomerular filtration rate (eGFR), mean arterial pressure, and proteinuria level at 12 months after kidney biopsy. The improvement ratio of eGFR at 12 months was significantly higher in the RASI group versus the non-RASI group [26% (−5 to 86) vs −2% (−20 to 20), p = 0.028, respectively], and the rate of change in eGFR beyond 12 months was similar between the 2 groups. During a mean followup of 80 months, 4 (23%) patients in the non-RASI group and 3 (8%) patients in the RASI group developed kidney disease progression. Early RAAS blockade significantly decreased the risk of kidney disease progression [HR = 0.11 (0.02–0.59); p = 0.010]. Proteinuria and hypertension controls were similar between the 2 groups.

Conclusion.

Early RAAS blockade improved the short-term and longterm renal outcomes in SLE patients with aPLN. The renal protective effect of RASI was independent of its antihypertensive and antiproteinuric effects.

Therapeutic plasma exchange for refractory SLE: A comparison of outcomes between different sub-phenotypes

Objective

Therapeutic plasma exchange (TPE) offers an alternative therapeutic modality for patients with systemic lupus erythematosus (SLE) and primary antiphospholipid syndrome (APS). However, there is conflicting evidence regarding its efficacy in different sub-phenotypes. This study aimed to investigate the main clinical characteristics and outcomes of patients with different phenotypes of SLE and APS treated with TPE at a tertiary care center.

Methods

The database of the Blood and Apheresis Unit between 2001 and 2013 was screened for patients with SLE and primary APS. SLE disease activity index (SELENA-SLEDAI), the indications for treatment, complications, and outcomes were obtained from a review of medical records and phone calls. A total of 24 patients (SLE: 20, APS: 4) were recruited for the study.

Results

Mean ages of SLE (M/F: 1/19) and primary APS (PAPS) patients (M/F: 2/2) were 32.4±12.89 and 52.0±10.7 years, respectively. The main indications for TPE were hematologic, neurologic, and pulmonary involvement and APS-related symptoms. TPE was preferred in eight patients because of leucopenia and co-infection. SLEDAI was significantly decreased after TPE (16.7±8.3 before vs. 8.8±3.1 after, p=0.001). Both primary APS and SLE-related catastrophic APS (CAPS) patients had completely responded to TPE. The success rate of TPE in patients with thrombocytopenia was lower than patients with hemolytic anemia. The median (IQR 25%-75%) number of TPE sessions was 6.5 (5-10.5). In total, five patients experienced TPE-related major adverse events (catheter infections in three patients, bleeding in one patient, and hypotension in one patient). The median (IQR 25%-75%) follow-up time was 33.5 (6.75-81.25) months. In total, four patients died during follow up, of which three died during the period of TPE administration.

Conclusion

Our data suggest that CAPS and other APS-related problems respond well to the TPE treatment. TPE should be kept in mind for the treatment of patients with other features of SLE, especially those resistant to other agents and in the presence of leucopenia.

Association of Anti-Ro/Sjögren's syndrome type A Antibodies and Complete Atrioventricular Block in an Adult With Sjögren's Syndrome

A 57-year-old female patient with underlying hypertension, dyslipidemia, membranous glomerulonephritis, and Sjögren's syndrome presented to our clinic with near-syncope and dizziness symptoms. We detected non-conducted sinus beat in 12-lead electrocardiography. An echocardiography showed that the left ventricular systolic function was preserved without a regional wall abnormality. The patient did not have symptoms of congestive heart failure or recent myocardial infarction. We observed complete atrioventricular block with longest pause of 6.2 seconds in a 24-hour Holter electrocardiography, and subsequently implanted a permanent pacemaker. Anti-Ro/Sjögren's syndrome type A antibodies are commonly seen in Sjögren's syndrome and associated with a neonatal complete heart block. The pathogenesis of anti-Ro/Sjögren's syndrome type A antibodies in the conduction system of an adult heart is still uncertain. In this article, we report Sjögren's syndrome in an adult patient with complete atrioventricular block and membranous glomerulonephritis, which may be associated with a positive titer of anti-Ro/Sjögren's syndrome type A antibodies.

Increased risk of chronic kidney disease in patients with rosacea: A nationwide population-based matched cohort study

Background

Rosacea is a chronic inflammatory skin disorder. Inflammation and oxidative stress are involved in the etiopathogenesis of rosacea and chronic kidney disease (CKD). This study aimed to investigate the association between rosacea and CKD.

Methods

This population-based cohort study identified 277 patients with rosacea in the Taiwan National Health Insurance Research Database during 2001–2005. These patients were matched for age, sex, and comorbidities with 2216 patients without rosacea. All subjects were individually followed-up for 8–12 years to identify those who subsequently developed CKD

Results

The incidence rates of CKD per 1000 person-years were 16.02 in patients with rosacea and 10.63 in the non-rosacea reference population. After adjusting for other covariates and considering the competing risk of mortality, patients with rosacea remained at increased risk of CKD (adjusted sub-distribution hazard ratio (aSD-HR) 2.00; 95% confidence interval (CI) 1.05–3.82). The aSD-HRs (95% CI) for CKD were 1.82 (0.83–4.00) and 2.53 (1.11–5.75) for patients with mild and moderate-to-severe rosacea, respectively.

Conclusions

Rosacea is an independent risk factor for CKD. High rosacea severity and old age further increased CKD risk in patients with rosacea. Careful monitoring for CKD development should be included as part of integrated care for patients with rosacea.

High-Dose Rituximab Ineffective for Focal Segmental Glomerulosclerosis: A Long-Term Observation Study

BACKGROUND

A beneficial effect of rituximab (RTX) on focal segmental glomerulosclerosis (FSGS) in pediatric patients or in transplant recipients has been reported in isolated cases. However, the use of RTX in adult patients with idiopathic FSGS needs further investigation.

METHODS

Eight patients who had biopsy-proven FSGS (63.9 ± 14.0, range 40-81 years, 4 women, 4 men) with major risk factors precluding corticosteroids or conventional immunosuppression were treated with a high dose of RTX (8 weekly doses of 375 mg/m2) and prospectively followed up for at least 2 years (29.1 ± 8.8 months, range 24-42 months).

RESULTS

RTX failed to improve proteinuria in 7 out of 8 patients, who had persistent nephrotic proteinuria. In one case, a rapidly deteriorating renal function was also observed. Only one patient showed an improvement in renal function and a remarkable reduction in proteinuria. There were no differences in clinical or laboratory characteristics or in the CD20 B lymphocyte count after RTX between the responder and the 7 nonresponder patients.

CONCLUSIONS

Only a minority (1 of 8) in our series of adult patients with FSGS showed positive effects of high doses of RTX. Future studies are warranted to investigate more promising therapeutic options in the management of FSGS.

Role of the Immune System in Hypertension

High blood pressure is present in more than one billion adults worldwide and is the most important modifiable risk factor of death resulting from cardiovascular disease. While many factors contribute to the pathogenesis of hypertension, a role of the immune system has been firmly established by a large number of investigations from many laboratories around the world. Immunosuppressive drugs and inhibition of individual cytokines prevent or ameliorate experimental hypertension, and studies in genetically-modified mouse strains have demonstrated that lymphocytes are necessary participants in the development of hypertension and in hypertensive organ injury. Furthermore, immune reactivity may be the driving force of hypertension in autoimmune diseases. Infiltration of immune cells, oxidative stress, and stimulation of the intrarenal angiotensin system are induced by activation of the innate and adaptive immunity. High blood pressure results from the combined effects of inflammation-induced impairment in the pressure natriuresis relationship, dysfunctional vascular relaxation, and overactivity of the sympathetic nervous system. Imbalances between proinflammatory effector responses and anti-inflammatory responses of regulatory T cells to a large extent determine the severity of inflammation. Experimental and human studies have uncovered autoantigens (isoketal-modified proteins and heat shock protein 70) of potential clinical relevance. Further investigations on the immune reactivity in hypertension may result in the identification of new strategies for the treatment of the disease.

Rediscovering Beta-2 Microglobulin As a Biomarker across the Spectrum of Kidney Diseases

There is currently an unmet need for better biomarkers across the spectrum of renal diseases. In this paper, we revisit the role of beta-2 microglobulin (β₂M) as a biomarker in patients with chronic kidney disease and end-stage renal disease. Prior to reviewing the numerous clinical studies in the area, we describe the basic biology of β₂M, focusing in particular on its role in maintaining the serum albumin levels and reclaiming the albumin in tubular fluid through the actions of the neonatal Fc receptor. Disorders of abnormal β₂M function arise as a result of altered binding of β₂M to its protein cofactors and the clinical manifestations are exemplified by rare human genetic conditions and mice knockouts. We highlight the utility of β₂M as a predictor of renal function and clinical outcomes in recent large database studies against predictions made by recently developed whole body population kinetic models. Furthermore, we discuss recent animal data suggesting that contrary to textbook dogma urinary β₂M may be a marker for glomerular rather than tubular pathology. We review the existing literature about β₂M as a biomarker in patients receiving renal replacement therapy, with particular emphasis on large outcome trials. We note emerging proteomic data suggesting that β₂M is a promising marker of chronic allograft nephropathy. Finally, we present data about the role of β₂M as a biomarker in a number of non-renal diseases. The goal of this comprehensive review is to direct attention to the multifaceted role of β₂M as a biomarker, and its exciting biology in order to propose the next steps required to bring this recently rediscovered biomarker into the twenty-first century.

Ectopic germinal center and megalin defect in primary Sjogren syndrome with renal Fanconi syndrome

Background

This study reports the clinical and pathological features of 12 cases of primary Sjogren syndrome (pSS) with renal involvement presenting with proximal tubular dysfunction in a single center, and investigates the possible correlation of ectopic germinal center formation and megalin/cubilin down-expression.

Method

Clinical and pathological records were reviewed. Immunohistochemistry was carried out to detect megalin, cubilin, CD21 and IL-17 expression.

Results

Patients presented with different degrees of proximal renal tubule lesion and decreased estimated glomerular filtration rate (eGFR). Renal biopsy revealed tubulointerstitial nephritis, with tubular epithelial cell degeneration, tubular atrophy, interstitial inflammation and focal fibrosis. Immunohistochemistry revealed decreased expression of megalin and cubilin, two important multiligand protein receptors on the brush border of proximal tubular epithelial cells. IL-17 secreted by Th17 subtype effector T cells was diffusely detected in the renal proximal tubule, with a negative correlation of IL-17 and megalin expression. In addition, ectopic germinal centers characterized by CD21⁺ follicular dendritic cells were present in the renal interstitium. In patients with a decreased eGFR, treatment with 4 weeks of glucocorticoid therapy resulted in an improved eGFR in 75% of patients.

Conclusion

We report 12 cases of pSS characterized by Fanconi syndrome. The decreased megalin and cubilin expression may contribute to the proximal tubular reabsorption defect, possibly secondary to Th17 infiltration and formation of ectopic germinal centers.

Kidney dysfunction in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PH) and chronic kidney disease (CKD) both profoundly impact patient outcomes, whether as primary disease states or as co-morbid conditions. PH is a common co-morbidity in CKD and vice versa. A growing body of literature describes the epidemiology of PH secondary to chronic kidney disease and end-stage renal disease (ESRD) (WHO group 5 PH). But, there are only limited data on the epidemiology of kidney disease in group 1 PH (pulmonary arterial hypertension [PAH]). The purpose of this review is to summarize the current data on epidemiology and discuss potential disease mechanisms and management implications of kidney dysfunction in PAH. Kidney dysfunction, determined by serum creatinine or estimated glomerular filtration rate, is a frequent co-morbidity in PAH and impaired kidney function is a strong and independent predictor of mortality. Potential mechanisms of PAH affecting the kidneys are increased venous congestion, decreased cardiac output, and neurohormonal activation. On a molecular level, increased TGF-β signaling and increased levels of circulating cytokines could have the potential to worsen kidney function. Nephrotoxicity does not seem to be a common side effect of PAH-targeted therapy. Treatment implications for kidney disease in PAH include glycemic control, lifestyle modification, and potentially Renin-Angiotensin-Aldosterone System (RAAS) blockade.