Faculty Bibliography

BACKGROUND:The American College of Chest Physicians (ACCP) and National Institutes for health and care Excellence in the United Kingdom (NICE) recommend that patients who are high risk for thrombotic events but require cessation of oral anticoagulation with warfarin, due to bleeding risk of a planned procedure, undergo bridging therapy with heparin. However, those conditions which are considered high risk are not universal, nor do guidelines differentiate between low molecular weight heparin (LMWH) and unfractionated heparin. Triple positive antiphospholipid syndrome (APS) is a thrombophilic state with a very high risk for thrombotic events during periods of anticoagulation cessation. Patients with secondary antiphospholipid syndrome in the setting of SLE may be at an even greater risk of thrombotic events during the perioperative period. PURPOSE/OBJECTIVE:Along with a review of the literature for perioperative management in APS we present three cases of triple positive secondary APS in systemic lupus erythematosus (SLE) patients who had severe thrombotic complications after cessation of their oral anticoagulation despite being bridged with LWMH. CONCLUSION/CONCLUSIONS:Given the severity and rapidity of thrombotic complications with low molecular weight heparin bridging, we propose that all patients with triple positive APS, especially secondary APS with SLE should undergo bridging therapy with intravenous UFH to reduce time without anticoagulation and minimize risk of thrombotic complications. Furthermore, we propose that NICE include APS in the list of medical conditions which are high risk for thrombotic complications and require bridging therapy.

OBJECTIVE:To evaluate seroreactivity and disease flares after COVID-19 vaccination in a multi-ethnic/racial cohort of patients with systemic lupus erythematosus (SLE). METHODS:90 SLE patients and 20 healthy controls receiving a complete COVID-19 vaccine regimen were included. IgG seroreactivity to the SARS-CoV-2 spike receptor-binding domain (RBD) and SARS-CoV-2 microneutralization were used to evaluate B cell responses; IFN-γ production to assess T cell responses was measured by ELISpot. Disease activity was measured by the hybrid SLE disease activity index (SLEDAI) and flares were assigned by the SELENA/SLEDAI flare index. RESULTS:Overall, fully vaccinated SLE patients produced significantly lower IgG antibodies against SARS-CoV-2 spike RBD than controls. Twenty-six SLE patients (28.8%) generated an IgG response below that of the lowest control (<100 units/ml). In logistic regression analyses, the use of any immunosuppressant or prednisone and a normal anti-dsDNA level prior to vaccination associated with decreased vaccine responses. IgG seroreactivity to the SARS-CoV-2 Spike RBD strongly correlated with the SARS-CoV-2 microneutralization titers and antigen-specific IFN-γ production determined by ELISpot. In a subset of patients with poor antibody responses, IFN-γ production was likewise diminished. Pre-/post-vaccination SLEDAI scores were similar. Only 11.4% of patients had a post-vaccination flare; 1.3% were severe. CONCLUSION/CONCLUSIONS:In a multi-ethnic/racial study of SLE patients 29% had a low response to the COVID-19 vaccine which was associated with being on immunosuppression. Reassuringly, disease flares were rare. While minimal protective levels remain unknown, these data suggest protocol development is needed to assess efficacy of booster vaccination.

OBJECTIVE:To describe the baseline characteristics of patients with positivity for antiphospholipid antibodies (aPLs) who were enrolled in an international registry, the Antiphospholipid Syndrome (APS) Alliance for Clinical Trials and International Networking (APS ACTION) clinical database and repository, overall and by clinical and laboratory subtypes. METHODS:GPI]) antibodies by aPL profiles (LAC only, single, double, and triple aPL positivity). RESULTS:GPI only. CONCLUSION:Our study demonstrates the heterogeneity of aPL-related clinical manifestations and laboratory profiles in a multicenter international cohort. Within single aPL positivity, LAC may be a major contributor to clinical events. Future prospective analyses, using standardized core laboratory aPL tests, will help clarify aPL risk profiles and improve risk stratification.

INTRODUCTION/BACKGROUND:Treatment failures for lupus nephritis (LN) are high with 10%-30% of patients progressing to end-stage renal disease (ESRD) within 10 years. Interstitial fibrosis/tubular atrophy (IFTA) is a predictor of progression to ESRD. Prior studies suggest that tubulointerstitial injury secondary to proteinuria in LN is mediated by complement activation in the tubules, specifically through the membrane attack complex (MAC). This study aimed to investigate the associations between tubular MAC deposition with IFTA and proteinuria. METHODS:In this cross-sectional study, LN kidney biopsies were assessed for MAC deposition by staining for Complement C9, a component of the MAC. Chromogenic immunohistochemistry was performed on paraffin-embedded human renal biopsy sections using unconjugated, murine anti-human Complement C9 (Hycult Biotech, clone X197). Tubular C9 staining intensity was analysed as present versus absent. IFTA was defined as minimal (<10%), mild (10%-24%), moderate (25%-50%) and severe (>50%). RESULTS:Renal biopsies from 30 patients with LN were studied. There were 24 (80%) female sex, mean age (SD) was 33 (12) years old and 23 (77%) had pure/mixed proliferative LN. Tubular C9 staining was present in 7 (23%) biopsies. 27 patients had minimal-to-mild IFTA and 3 patients had moderate IFTA. Among the C9 + patients, 3 (43%) had moderate IFTA as compared with none in the C9- group, p=0.009. C9 + patients had higher median (IQR) proteinuria as compared with C9- patients: 6.2 g (3.3-13.1) vs 2.4 g (1.3-4.6), p=0.001 at the time of biopsy. There was no difference in estimated glomerular filtration rate (eGFR) between the C9 + and C9- groups. CONCLUSION/CONCLUSIONS:This study demonstrated that tubular MAC deposition is associated with higher degree of IFTA and proteinuria, which are predictors of progression to ESRD. These results suggest that tubular MAC deposition may be useful in classification of LN. Understanding the role of complement in tubulointerstitial injury will also identify new avenues for LN treatment.

Background Lupus nephritis (LN) is characterized by considerable variability in its clinical manifestations and histopathological findings. Understanding the cellular and molecular mechanisms underlying this heterogeneity is key for the development of personalized treatments for LN. Methods Droplet-based single-cell RNA-sequencing was applied to the analysis of dissociated kidney samples, collected from 155 LN patients with active kidney disease and 30 living donor controls as part of the Accelerating Medicines Partnership (AMP) in SLE consortium -a large-scale, multi-center study. 73,440 immune cells passing quality control were identified, spanning 134 cell subsets, representing various populations of tissue-resident and infiltrating leukocytes, as well as the activation states these cells assume as part of their diseaserelated activation and differentiation (figure 1). Principal component analysis (PCA) was used to characterize the variability in cell subset frequencies across the LN patients. Relationships between the resulting principal components (PCs) and the demographic, clinical and histopathological features of the patients were then assessed. Results The main source of variability in immune cell subset frequencies, as represented by the first PC (PC1), reflected the balance between lymphocytes and monocytes/macrophages. Subsequent PCs represented the balance between B cells and T cells (PC2); the levels of cytotoxic T lymphocytes and NK cells, as compared to plasma cells (PC3); and the degree of macrophage differentiation to an alternatively activated phagocytic profile (PC4). PC1 was significantly correlated with the Chronicity index, such that patients with a higher percentage of lymphocytes compared to monocytes/macrophages had a higher Chronicity score (rho = -0.422, p-value < 0.001; figure 2A). A high degree of macrophage differentiation, as represented by PC4, was associated with a high Activity score (rho = 0.387, p-value < 0.001; figure 2B), and, in addition, with proliferative or mixed histology class, compared to pure membranous nephritis (p-value = 0.001, Kruskal-Wallis test). The ratio of B cells to T cells, as represented by PC2, demonstrated a positive correlation with the Activity index (rho = 0.311, p-value < 0.001). We further identified a significant correlation of PC1 with age; specifically, older patients had a higher relative frequency of lymphocytes compared to monocytes/macrophages (rho = -0.239, p-value = 0.003). Our analysis indicated that these relations are not driven by demographic, clinical and technical sources of variation in our data, including race, ethnicity, the mixture of different nephritic classes, and the inclusion of both first and later biopsies. Conclusion Our work identifies distinct leukocyte populations active in different LN patients and, possibly, different stages of disease, and points to potential therapeutic targets, that must be validated in mechanistic studies. This approach may pave the way to personalized treatment of LN

Coronavirus disease 2019 (COVID-19) is associated with a high rate of thrombosis. Prolonged activated partial thromboplastin times (aPTT) and antiphospholipid antibodies (aPL) are reported in COVID-19 patients. The majority of publications have not reported whether patients develop clinically relevant persistent aPL, and the clinical significance of new aPL-positivity in COVID-19 is currently unknown. However, the reports of aPL-positivity in COVID-19 raised the question whether common mechanisms exist in the pathogenesis of COVID-19 and antiphospholipid syndrome (APS). In both conditions, thrombotic microangiopathy resulting in microvascular injury and thrombosis is hypothesized to occur through multiple pathways, including endothelial damage, complement activation, and release of neutrophil extracellular traps (NETosis). APS-ACTION, an international APS research network, created a COVID-19 working group that reviewed common mechanisms, positive aPL tests in COVID-19 patients, and implications of COVID-19 infection for patients with known aPL positivity or APS, with the goals of proposing guidance for clinical management and monitoring of aPL-positive COVID-19 patients. This guidance also serves as a call and focus for clinical and basic scientific research.

BACKGROUND:Antiphospholipid syndrome (APS) is characterized by episodes of thrombosis, obstetric morbidity or both, associated with persistently positive antiphospholipid antibodies (aPL). Studying the profile of a rare disease in an admixed population is important as it can provide new insights for understanding an autoimmune disease. In this sense of miscegenation, Brazil is characterized by one of the most heterogeneous populations in the world, which is the result of five centuries of interethnic crosses of people from three continents. The objective of this study was to compare the clinical and laboratory characteristics of Brazilian vs. non-Brazilian primary antiphospholipid syndrome (PAPS) patients. METHODS:We classified PAPS patients into 2 groups: Brazilian PAPS patients (BPAPS) and PAPS patients from other countries (non-BPAPS). They were compared regarding demographic characteristics, criteria and non-criteria APS manifestations, antiphospholipid antibody (aPL) profile, and the adjusted Global Antiphospholipid Syndrome Score (aGAPSS). RESULTS:We included 415 PAPS patients (88 [21%] BPAPS and 327 [79%] non-BPAPS). Brazilian patients were significantly younger, more frequently female, sedentary, obese, non-white, and had a higher frequency of livedo (25% vs. 10%, p < 0.001), cognitive dysfunction (21% vs. 8%, p = 0.001) and seizures (16% vs. 7%, p = 0.007), and a lower frequency of thrombocytopenia (9% vs. 18%, p = 0.037). Additionally, they were more frequently positive for lupus anticoagulant (87.5% vs. 74.6%, p = 0.01), and less frequently positive to anticardiolipin (46.6% vs. 73.7%, p < 0.001) and anti-ß2-glycoprotein-I (13.6% vs. 62.7%, p < 0.001) antibodies. Triple aPL positivity was also less frequent (8% vs. 41.6%, p < 0.001) in Brazilian patients. Median aGAPSS was lower in the Brazilian group (8 vs. 10, p < 0.0001). In the multivariate analysis, BPAPS patients still presented more frequently with livedo, cognitive dysfunction and sedentary lifestyle, and less frequently with thrombocytopenia and triple positivity to aPL. They were also less often white. CONCLUSIONS:Our study suggests a specific profile of PAPS in Brazil with higher frequency of selected non-criteria manifestations and lupus anticoagulant positivity. Lupus anticoagulant (not triple positivity) was the major aPL predictor of a classification criteria event.

Background/Purpose: The clinical heterogeneity of SLE with its complex pathogenesis remains challenging as we strive to provide optimal management. The contribution of platelets to endovascular homeostasis, inflammation and immune regulation highlights their potential importance in SLE. Prior work from our group showed that the Fcgamma receptor type IIa (FcgammaRIIa)-R/H131 biallelic polymorphism is associated with increased platelet activity and cardiovascular risk in SLE. The study was initiated to investigate the platelet transcriptome in patients with SLE and evaluate its association across FcgammaRIIa genotypes and distinct clinical features.
Method(s): RNA-sequencing was done on platelets isolated from 51 patients fulfilling criteria for the classification of SLE based on recent EULAR/ACR definitions, and 18 healthy controls matched on age, sex, and race. Unsupervised clustering, differential gene expression, and gene set enrichment analysis (GSEA) were used to analyze differences between SLE patients and controls, and SLE subpopulations, based on SELENA SLEDAI Hybrid disease activity, specific organ manifestations, and FcgammaRIIa genotype. Weighted Gene Correlation Network Analysis (WGCNA) was performed to create a modular transcriptomic framework.
Result(s): Our cross-sectional SLE cohort (N=51, age = 41.1+/-12.3, 100% female, 45% Hispanic, 24% black, 22% Asian, 51% white, SLEDAI = 4.4+/-4.2) was comprised of patients consecutively enrolled excluding those on aspirin or anticoagulants. Compared to the 18 controls, there were 2290 (p.adj < 0.05) differentially expressed genes. ( Figure 1 A, B) GSEA revealed positive enrichment for pathways related to interferon response, TNFa signaling, and coagulation in SLE. ( Figure 1C) WGCNA was used to create a modular transcriptomic framework. ( Figure 2A ) Modules enriched for platelet activity, immune response, and WNT signaling were significantly increased in SLE versus controls. Moreover, modules enriched for interferon response and WNT signaling paralleled increases in disease activity. ( Figure 2B) When analyzing patients with proteinuria, modules associated with oxidative phosphorylation and platelet activity were unexpectedly decreased. (Figure 2C) Analyzing the ratio of fold changes between SLE/Control vs SLE Proteinuria/SLE No Proteinuria, genes increased in SLE and those with proteinuria were enriched for immune effector processes, while genes increased in SLE but decreased in proteinuria were enriched for coagulation and cell adhesion. (Figure 2D) The module enriched for FCR activation was decreased in SLE and was affected by the FcgammaRIIa genotype. (Figure 3A) FcgammaRIIa R131 and H131 patients showed significantly different platelet transcriptomes. (Figure 3B) The combination of SLE with an FcgammaRIIa R131 variant leads to a significant increase in the platelet activity module not seen in controls. (Figure 3C)
Conclusion(s): These analyses reveal that SLE patients have a significantly different platelet transcriptome from controls, different phenotypic presentations of SLE patients associate with distinct platelet transcriptomic signatures, and FCGR2a variants may differentially influence the role of platelets in the contribution to SLE disease activity