Lupus Nephritis Biomarkers: A Critical Review.

Lupus nephritis (LN), a major complication in individuals diagnosed with systemic lupus erythematosus, substantially increases morbidity and mortality. Despite marked improvements in the survival of patients with severe LN over the past 50 years, complete clinical remission after immunosuppressive therapy is achieved in only half of the patients. Therefore, timely detection of LN is vital for initiating prompt therapeutic interventions and improving patient outcomes. Biomarkers have emerged as valuable tools for LN detection and monitoring; however, the complex role of these biomarkers in LN pathogenesis remains unclear. Renal biopsy remains the gold standard for the identification of the histological phenotypes of LN and guides disease management. However, the molecular pathophysiology of specific renal lesions remains poorly understood. In this review, we provide a critical, up-to-date overview of the latest developments in the field of LN biomarkers.

Interrelation of T cell cytokines and autoantibodies in systemic lupus erythematosus: A cross-sectional study.

T-helper cytokines interferon gamma (IFNÉ£), interleukin 17 (IL-17) and IL-10 impact systemic lupus erythematosus (SLE) directly and indirectly via modulation of autoAb production. We determined the separate and combined effects on clinical manifestations of SLE (N = 62). IFNÉ£, IL-17 but not IL-10 were significantly elevated in patients with SLE. IFNÉ£ positively correlated with anti-DNA and anti-SSA. IL-17 positively correlated with anti-SSA and was significantly higher in patients with discoid rash and class V LN. IL-10 did not correlate with circulating autoantibodies but was significantly elevated in patients with LN. Patients with LN had elevated plasma levels of anti-DNA and anti-Sm/ribonuclear protein (RNP). Anti-Sm/RNP levels were decreased in patients with acute mucocutaneous manifestations, including photosensitivity and/or malar rash. The study provides critical insights into pathological mechanisms of LN, which could help guide future diagnoses and therapies.

Increased development of T-bet+CD11c+ B cells predisposes to lupus in females: Analysis in BXD2 mouse and genetic crosses.

Cardinal features of lupus include elevated B cell activation and autoantibody production with a female sex preponderance. We quantified interactions of sex and genetic variation on the development of autoimmune B-cell phenotypes and autoantibodies in the BXD2 murine model of lupus using a cohort of backcrossed progeny (BXD2 x C57BL/6J) x BXD2. Sex was the key factor leading to increased total IgG, IgG2b, and autoantibodies. The percentage of T-bet+CD11c+ IgD+ activated naive B cells (aNAV) was higher in females and was associated with increased T-bet+CD11c+ IgD- age-related B cells, Fas+GL7+ germinal center B cells, Cxcr5-Icos+ peripheral T-helper cells, and Cxcr5+Icos+ follicular T-helper cells. IFN-ß was elevated in females. Variation in aNAV cells was mapped to Chr 7 in a locus that shows significant interactions between the female sex and heterozygous B/D variant. Our results suggest that activation of naive B cells forms the basis for the female-predominant development of autoantibodies in lupus-susceptible BXD2 mice.

How to Use Janus Kinase Inhibitors in the Treatment of Rheumatoid Arthritis? A Clinical Assessment of Risks and Benefits.

PURPOSE OF REVIEW: To provide an updated understanding of risks and benefits of Janus kinase inhibitors (JAKi) versus biologic disease-modifying antirheumatic drugs (bDMARDs) in the management of rheumatoid arthritis (RA). RECENT FINDINGS: Shared decision-making is needed in choosing between JAKi and bDMARDs. Cardiovascular disease, malignancy, and thromboembolic events guide this choice. In patients with active RA despite methotrexate use, tumor necrosis factor inhibitor is conditionally favored over JAKi for low-cardiovascular-risk patients and strongly favored in those with pre-existing cardiovascular disease or multiple cardiovascular risk factors. Suboptimal treatment of treatment-refractory RA patients may pose a greater absolute cardiovascular risk than with JAKi use. Use of aspirin and statin may be considered to reduce cardiovascular risk. New safety data on JAKi has redefined the treatment approach in RA. JAKi remains an important oral medication option in active RA despite treatment with bDMARDs, especially in those with low cardiovascular risk.

IL-4 receptor blockade is a global repressor of naïve B cell development and responses in a dupilumab-treated patient.

Here, we report a case of atopic dermatitis (AD) in a patient who received biweekly doses of dupilumab, an antibody against the IL-4 receptor α chain (IL-4Rα). Single cell RNA-sequencing showed that naïve B cells expressed the highest levels of IL4R compared to other B cell subpopulations. Compared to controls, the dupilumab-treated patient exhibited diminished percentages of IL4R+IGHD+ naïve B cells and down-regulation of IL4R, FCER2 (CD23), and IGHD. Dupilumab treatment resulted in upregulation of genes associated with apoptosis and inhibition of B cell receptor signaling and down-regulation of class-switch and memory B cell development genes. The dupilumab-treated patient exhibited a rapid decline in COVID-19 anti-spike and anti-receptor binding domain antibodies between 4 and 8 and 11 months post COVID-19 vaccination. Our data suggest that intact and persistent IL-4 signaling is necessary for maintaining robust survival and development of naïve B cells, and maintaining a long term vaccine response.

Clustering Patients With Gout Based on Comorbidities and Biomarkers: A Cross-Sectional Study.

OBJECTIVE: This single-center clinical study identifies clusters of different phenotypes and pathophysiology subtypes of patients with gout and associated comorbidities. METHODS: Patients clinically diagnosed with gout were enrolled between January 2018 and December 2019. Hierarchical cluster analyses were performed using clinical data or biological markers, inflammatory markers, and oxidative stress pathway metabolites assayed from serum and plasma samples. Subgroup clusters were compared using ANOVA for continuous data and chi-square tests for categorical data. RESULTS: Hierarchical cluster analysis identified 3 clusters. Cluster 1 (C1; n = 24) comprised dyslipidemia, hypertension, and early-onset gout, without tophi. Cluster 2 (C2; n = 25) comprised hypertension, dyslipidemia, nephrolithiasis, and obesity. Cluster 3 (C3; n = 39) comprised multiple comorbidities and tophi. Post hoc comparisons of data obtained from samples of patients in C1, C2, and C3 revealed significant differences in the levels of oxidative stress and inflammation-related markers, including 3-nitrotyrosine, tumor necrosis factor, C-reactive protein, interleukin (IL) 1ß, IL-6, platelet-derived growth factor (PDGF)-AA, and PDGF-BB. Reclustering patients based on all markers as well as on the biological markers that significantly differed among the initial clusters identified similar clusters. CONCLUSION: Oxidative stress and inflammatory marker levels may affect the development and clinical manifestations (ie, clinical phenotypes) of gout. Measuring oxidative stress and levels of inflammatory cytokines is a potential adjunctive tool and biomarker for early identification and management of gout.

Lupus nephritis correlates with B cell interferon-ß, anti-Smith, and anti-DNA: a retrospective study.

BACKGROUND: In systemic lupus erythematosus (SLE), detection of interferon-ß (IFNß) in B cells was found to be most prominent in patients with high anti-Smith (Sm) and renal disease, but a mechanistic connection was not clear. The objective of the present study is to determine the association of IFNß in peripheral blood naïve B cells with the histopathological features of lupus nephritis (LN). METHODS: The percentage of IFNß+ cells in IgD+CD27- naïve CD19+ B cells (B cell IFNß) among peripheral blood mononuclear cells (PBMCs) from 80 SLE patients were analyzed using flow cytometry. Serological and clinical data were collected. The correlations of B cell IFNß with LN classification and with histopathological findings (light, electron, and immunofluorescence [IF] microscopic analyses for deposition of IgM, IgG, IgA, C1q, and C3) were determined in 23 available biopsy specimens. RESULTS: B cell IFNß is positively associated with anti-Sm (p = 0.001), anti-DNA (p = 0.013), and LN (p < 0.001) but was negatively associated with oral/nasal ulcer (p = 0.003) and photosensitivity (p = 0.045). B cell IFNß positively correlated with immune complex (IC) deposit in the glomerular basement membrane (GBM) (p = 0.002) but not in the mesangial (p = 0.107) or tubular region (p = 0.313). Patients with high B cell IFNß had statistically increased development of the proliferative LN (Classes III, IV and/or V), compared to patients with low B cell IFNß (p < 0.0001). Histopathological features positively associated with increased B cell IFNß included active glomerular lesions as determined by fibrocellular crescents (p = 0.023), chronic glomerular lesions indicated by segmental sclerosis (p = 0.033), and a membranous pattern of renal damage indicated by spike/holes (p = 0.015). CONCLUSION: B cell IFNß correlates with history of severe LN, glomerular basement membrane (GBM) IC deposition, and anatomical features of both active and chronic glomerular lesions.

Host Genetics But Not Commensal Microbiota Determines the Initial Development of Systemic Autoimmune Disease in BXD2 Mice.

OBJECTIVE: To determine the extent to which the gut microbiome influences systemic autoimmunity in a mouse model of lupus. METHODS: We generated germ-free (GF) lupus-prone BXD2 mice, which under normal conditions develop spontaneous germinal centers (GCs) and high titers of serum autoantibodies. GF status was confirmed by gut bacterial culture. The autoimmune phenotypes of 6- and 12-month-old gnotobiotic GF BXD2 mice and specific pathogen-free (SPF) BXD2 mice were compared. Serum levels of autoantibodies were measured by enzyme-linked immunosorbent assay. Histologic sections of the mouse kidney and joints were evaluated. Flow cytometry was used to analyze GCs and age-associated B cells. CD4+ T cells were analyzed for PD-1+ICOS+ activated T cells, T follicular regulatory (Tfr) cells (Foxp3+CD25+ PD-1+CXCR5+), and PD-1+ICOS+ T cells expressing interleukin-17A (IL-17A) or interferon-γ (IFNγ) after stimulation with phorbol myristate acetate (PMA)/ionomycin. RESULTS: In 6-month-old mice, GF status did not affect splenomegaly, GC B cells, age-associated B cells, or serum autoantibody levels, except for IgG antihistone. GF BXD2 mice exhibited a significantly higher percentage of Tfr cells compared to their SPF counterparts (P < 0.05). At 12 months of age, however, GF BXD2 mice had significantly diminished IgG autoantibody levels and a lower percentage of GC B cells and age-associated B cells (P < 0.05). Following stimulation with PMA/ionomycin, PD-1+ICOS+ CD4+ T cells expressed significantly lower IL-17A, but not IFNγ, levels in GF BXD2 mice compared to SPF BXD2 mice (P < 0.01). SPF BXD2 mice and GF BXD2 mice developed equivalent renal and joint disease with no significant differences in severity. CONCLUSION: Our results suggest a model in which genetics plays a dominant role in determining the initial development of autoimmunity. In contrast, gut microbiomes may regulate the persistence of certain aspects of systemic autoimmunity.

Mycobacterium tuberculosis in solid organ transplantation: incidence before and after expanded isoniazid prophylaxis.

BACKGROUND: The risk of tuberculosis is increased in solid organ transplantation. Rates remain high in developed and developing countries. We developed protocols to better identify transplant recipients at risk of tuberculosis and initiate interventions to prevent tuberculosis. OBJECTIVES: Report tuberculosis incidence in solid-organ transplant recipients and the results of expanded isoniazid prophylaxis in deceased-donor renal transplantation. DESIGN: Retrospective cohort study, comparing two time periods. SETTING: Large transplantation center in a WHO-medium endemicity country for tuberculosis. METHODS: In a cohort of all solid-organ transplant recipients performed between 2003 and 2012, tuberculosis-free transplantation follow-up is used for incidence calculation. Rates of tuberculosis in renal transplant recipients are compared before and after implementation of expanded isoniazid prophylaxis. MAIN OUTCOME MEASURE(S): Active tuberculosis post-transplantation. RESULTS: Of 1966 solid-organ transplant recipients (kidney: 1391, liver: 426, heart: 114, lung: 35), 20 recipients (1.02%) developed tuberculosis. Twelve cases (60%) developed tuberculosis within one year of transplantation. The incidence was 248 cases per 100 000 transplant-years. The proportion of transplant recipients (incidence of tuberculosis per 100 000 transplant-years) for specific organs were kidney 0.58% (127), liver 1.88% (594), heart: 1.75% (570), and lung 5.71% (4750). In the survival analysis, lung transplant recipients had significantly higher rates of tuberculosis compared to recipients of kidneys from living donors (P=.0001) with a rate ratio of 45.3 (95% CI: 7-313). Mortality was 5% among tuberculosis patients. After implementing expanded isoniazid prophylaxis among deceased-donor kidney recipients, no tuberculosis occurred in 177 recipients, compared to 3 out of 155 (2%) recipients before implementation. CONCLUSIONS: Rates of tuberculosis among our solid transplant recipients are decreasing. Universal iso-niazid prophylaxis in transplant recipients could reduce transplant-associated tuberculosis in endemic areas. LIMITATIONS: Donor data on tuberculosis exposure and prevention and tuberculosis prevention efforts before referral to our center are not available for all patients.