Faculty Bibliography

Background/Purpose: A decline of urine protein-to-creatinine ratio (UPCR) to < 0.5 is associated with better long-term preservation of kidney function in lupus nephritis (LN). UPCR < 0.5 defines complete response in guidelines and clinical trials when achieved after 1 or 2 years. Biomarkers of early response are needed to guide early treatment changes. We studied longitudinal urine proteomic profiles in LN to identify early predictors of proteinuric response.
Method(s): We quantified 1200 biomarkers (Kiloplex, RayBiotech) in urine samples collected on the day of (73%) or within 3 weeks (27%) of kidney biopsy and week 12, 24, or 52 in LN patients (ISN class III, IV, V, or mixed) with proteinuria > 1 g/d. Response was defined at one year from renal biopsy: Complete = UPCR < 0.5, serum creatinine (sCr) < 125% of baseline, prednisone <= 10mg/d; Partial = UPCR < 50% from baseline but >0.5, sCr < 125% of baseline, but prednisone allowed to 15 mg/d; Non responder = not meeting previous definitions.
Result(s): A total of 127 patients were included: 48 (38%) with pure proliferative LN (class III or IV), 41 (32%) with mixed LN (III or IV +/-V), and 38% (30%) with pure membranous LN. Response was complete in 34 (27%), partial in 29 (23%), and none in 64 (50%). There were no urinary biomarkers at baseline that predicted response. We then analyzed the changes in urinary proteins at 3 months compared to baseline. Patients who responded at 1 year showed an early decline in 51 urinary proteins led by CD163, IL-16, and macrophage mannose receptor (MMR, CD206) (Figure 1A) which matched the proteomic signature associated with histological activity (Figure 1B). No changes were observed in nonresponders. The decline of several urinary biomarkers at 3 months outperformed a decline in UPCR (clinical standard) in predicting the 1 year response (-Figure 2A). In particular, a decline of CD163 predicted 1 year response in ROC analysis with an area under the curve (AUC) of 83% compared to an AUC of 75% for UPCR decline (Figure 2B). In proliferative LN, urinary biomarkers displayed superior performance with an AUC of 91%, 86%, and 78% for the decline of MMR, CD163, and UPCR, respectively (-Figure 2C-D). Pathway enrichment analysis identified leukocyte activation, neutrophil degranulation, and matrix degradation as the main pathways reduced at 3 months in responders.
Conclusion(s): An early decline in urinary biomarkers of histological activity is associated with proteinuric response at 1 year. These findings indicate that effective immunosuppression induces by three months an immunological response in the kidney that can be noninvasively monitored in the urine. Biomarkers of immunological response outperformed early decline of UPCR, the standard of care, in predicting 1-year proteinuric response, especially in proliferative LN. Because biomarkers of immunological response parallel intrarenal activity, they could detect early treatment response/failure and allow early treatment changes. They could serve as surrogate endpoints in clinical trials. Longitudinal studies are needed to confirm that this immunological response is a better predictor of long-term kidney function preservation than proteinuric responses. Figure 1. Proteins linked to intrarenal activity (NIH activity index) decrease in treatment responders. Volcano plot of the changes of the urinary proteomic profile of treatment responders at 3 months (A) after kidney biopsy/treatment compared to baseline at time of biopsy. (B) Volcano plot displaying the Spearman's correlation coefficients of urinary biomarkers at time of biopsy with histological activity defined as the NIH activity index. Blue arrows indicate 4 examples of shared urinary biomarkers that indicate both intrarenal activity and response to treatment. FDR, false discovery rate; q, adjusted p value

Background/Purpose: SLE is characterized by autoantibody production. The most common lupus-specific serology is the anti-dsDNA antibody (anti-DNA). Traditionally, anti-DNA is measured by an enzyme immunoassay or equivalent such as multiplex flow immunoassay (EIA), which is considered sensitive. In contrast, the crithidia luciliae immunofluorescence test (CLIFT) is considered more specific. Serial measurement of anti-DNA is often used to monitor lupus disease activity. With NYU's extensive multi-race/ethnic lupus registry, we studied the relationship between these two methods, their association with lupus nephritis (LN), and their ability to predict subsequent flares.
Method(s): Using the NYU Lupus Registry of patients who meet ACR, SLICC, or EULAR criteria, we identified patients who had one or more simultaneous anti-DNA results by multiplex EIA and CLIFT. We report on their concordance (e.g., always, never, or fluctuating), association with LN, and ability to predict flare within 90 days using the SELENA-SLEDAI Flare Index. To account for degree of positivity, we defined tertiles for EIA and CLIFT as low positive [11-50 and 1:10-1:40], mild positive [51-200 and 1:80-1:320], and high positive [> 200 and > 1:640]. Table 1. 586 total visits with paired EIA and CLIFT. H = high positive M = mild positive L = low positive defined in Methods section Table 2. Relationship between EIA, CLIFT and hypocomplementemia with lupus nephritis. Chi-square test comparing significance between 60/100 v 72/100 (EIA/CLIFT) p = 0.07 Table 3. Relationship between EIA, CLIFT, hypocomplementemia and flare within 90 days Results: 207 patients had one or more paired anti-DNA results generating 586 paired results (Table 1). Cohort demographics: 92% Female, 22% Hispanic ethnicity, 24% Black, 16% Asian, 49% White, 10% Other. Overall, 377 pairs were always concordant, and 209 were never concordant. 236 pairs demonstrated titer concordance and 350 with titer discordance. Of the 207 patients, 64 patients had only one and 143 patients had two or more paired tests. Of the 64 patients, 46 were always concordant: 18 had positive EIA/CLIFT and 28 had negative EIA/CLIFT. The remaining 18 patients were never concordant: 8 had +EIA/-CLIFT and 10 had-EIA/+CLIFT. The concordance of the 143 patients with multiple paired results: 73 always, 23 never, and 47 fluctuating. Whether by one or multiple paired tests, 41/207 patients were never concordant. 100 of the 207 patients had LN associated with +EIA in 60 and +CLIFT in 72 (Table 2). Hypocomplementemia was present in 88% of +EIA and 89% of +CLIFT patients with LN. 51 visits in 42 patients had paired anti-DNA results and a SELENA-SLEDAI Flare Index assessment within 90 days. 7 patients had mild flares with +EIA in 4 and +CLIFT in 3. 4 patients had severe flares with +EIA and +CLIFT in 3 (Table 3). Low C3 and or C4 occurred in 1 of 7 (14%) mild flares and in 4 of 4 (100%) severe flares.
Conclusion(s): Our data demonstrate that discordance of positivity between two assays for anti-DNA occurred in 41/207 (20%) patients, in 207/586 (36%) visits and in 350/586 (60%) visits magnitude of positivity nonconcordant. EIA positivity is associated with LN less often than CLIFT positivity. Flares were infrequent and associated with either EIA or CLIFT positivity, with severe flares more likely if accompanied by hypocomplementemia. We recommend the utility of more than one anti-DNA assay in routine monitoring for lupus disease activity

Background/Purpose: Fractures in patients with systemic lupus erythematosus (SLE) are more common than age and sex matched controls. Fracture risk is traditionally assessed by dual-energy X-ray absorptiometry (DEXA) measured BMD and refined using the Fracture Risk Assessment Tool (FRAX). Several studies have demonstrated fractures in SLE patients despite normal DEXA BMD. We hypothesize that changes in bone microarchitecture may explain fracture vulnerability in SLE. This study was initiated to characterize bone quality by evaluating measures of microarchitecture at the proximal femur via 3T MRI in patients with SLE and compare these measurements with a control group of patients with known low bone density (LBD) and osteoporosis (OP).
Method(s): 50 SLE patients and 177 controls with known LBD or OP underwent DEXA and 3T MRI of the non-dominant hip. DEXA measured BMD of the total hip, femoral neck, and spine. LBD was defined as Z score <=-2.0 in premenopausal women and men younger than fifty, and T score <=-1.0 in others. OP was defined as the presence of LBD and history of fragility fracture in premenopausal women and men younger than fifty, and T score <=-2.5 in others. MRI measured favorable microarchitectural characteristics trabecular plate width (PW), trabecular plate-to-rod ratio (PRR), plate volume fraction (PVF), trabecular bone thickness (Tb.Th), and trabecular network area (NA), as well as unfavorable characteristics rod volume fraction (RVF) and trabecular spacing (Tb.Sp). Demographics, medication use and inflammatory markers at the time of the study visit were recorded. Statistical analysis was performed using Pearson correlations, t-scores, and multivariable linear regressions as appropriate.
Result(s): 50 SLE patients and 177 patients with LBD or OP completed all imaging studies. The SLE cohort was younger, and a higher percent of black patients compared to controls (Table 1). SLE patients had lower MRI PW and PRR and higher Tb. Sp as compared to controls, while having higher DEXA BMDs at all sites after adjustment for confounders (Figure 1). SLE patients had an inverse relationship between ESR and PW, PRR, Tb.Th, and NA (Figure 2, A-D). Similar results were found with CRP, which had an inverse relationship with PW, PRR, and NA. Body mass index (BMI) in SLE patients had an inverse relationship between PW, PVF, Tb.Th, and NA (Figure 2, E-H), and a positive relationship between all measured BMDs. In the control group, similar relationships were found between BMI and BMD, but only Tb.Th was inversely associated with BMI. Age, current steroid use, and history of lupus nephritis were not associated with MRI measures of bone microarchitecture.
Conclusion(s): Compared to controls, SLE patients had decreased bone quality as measured by MRI bone microarchitecture, despite having higher DEXA BMD. Elevated inflammatory markers inversely associated with bone quality. Elevated BMI, despite its association with higher BMD, was also associated with lower measures of bone microarchitectural strength, unlike controls. Further connection of bone microarchitecture to fracture risk and change over time in patients with SLE are needed to determine clinical significance of these findings and to guide additional monitoring and potential treatments. A-C: multivariate linear regression adjusting for significant microarchitectural confounders of BMI and gender. D-F: multivariate linear regression adjusting for significant BMD confounders of age, BMI, race, and gender

Background/Purpose: Patients with systemic lupus erythematosus (SLE) are at high risk for severe disease from COVID-19 and decreased vaccine efficacy, due to inherent immune perturbations and frequent immunosuppressant use. The impact of vaccine responses was "pressure" tested in New York City (NYC) from December 2021-February 2022, due to the highly infectious omicron BA.1 variant which resulted in a significant increase in COVID-19 cases and hospitalizations. This study was performed to assess clinical efficacy and seroreactivity in SLE patients with and without an additional vaccination dose after initial vaccine series, particularly during the omicron BA.1 surge in NYC.
Method(s): COVID-19 infections after vaccination were evaluated during patient encounters and chart review in subjects from the NYU Lupus Cohort who received an initial SARS-CoV-2 vaccine series with follow-up for at least 6 months or until breakthrough infection. Clinical follow-up was required after February 4, 2022 (when NYC COVID-19 cases returned to their preomicron BA.1 baseline), with last patient follow-up recorded April 24, 2022. Positive PCR or antigen-based testing was required, performed at the clinical site or self-reported. Fifty-seven patients receiving additional vaccine doses were evaluated longitudinally for recombinant SARS-CoV-2 spike receptor binding domain antibodies (#BT10500; R&D Systems). Low post-vaccine antibody response was defined as <=100 units/ml.
Result(s): Among the 163 subjects evaluated, 125 (76.7%) received an additional COVID-19 vaccination after the initial series. Demographics and medication usage were similar in patients who did and did not receive the additional vaccination dose, with 50% on at least one immunosuppressant and 16% on more than one at the time of the initial vaccine. Twentyeight (63.6%) of the 44 patients with a breakthrough infection had received an additional vaccination compared to 97 (81.5%) of the 119 without breakthrough infection (p=0.022) (Table 1). Of the 44 COVID-19 cases, only 2 occurred prior to the omicron wave, both in patients who did not receive the additional dose. There were no COVID-19 related deaths and two patients were hospitalized. Among the 57 patients with serologic evaluation, the median antibody level after initial vaccination series was 397 u/mL (IQR 57-753), and 1036 (IQR 517-1338.5) after the additional dose. After initial vaccination, 21 (37%) had low ELISA responses, but only 4 (7%) continued to have low responses after the additional dose. There was no association between the level of antibody after the additional dose and COVID-19 breakthrough.
Conclusion(s): SLE patients from a cohort of patients in NYC who received an additional SARS-CoV-2 vaccine dose were significantly less likely to have a subsequent COVID-19 infection compared to those who only completed their initial vaccine series. SLE patients demonstrated an improvement in serologic response after an additional dose of SARS-CoV-2 vaccine. The mild disease in all vaccinated patients is reassuring given the risks inherent and frequent immunosuppressant use in this patient population

OBJECTIVES/OBJECTIVE:A perception derived from cross-sectional studies of small systemic lupus erythematosus (SLE) cohorts is that there is a marked discrepancy between antinuclear antibody (ANA) assays, which impacts on clinicians' approach to diagnosis and follow-up. We compared three ANA assays in a longitudinal analysis of a large international incident SLE cohort retested regularly and followed for 5 years. METHODS:Demographic, clinical and serological data was from 805 SLE patients at enrolment, year 3 and 5. Two HEp-2 indirect immunofluorescence assays (IFA1, IFA2), an ANA ELISA, and SLE-related autoantibodies were performed in one laboratory. Frequencies of positivity, titres or absorbance units (AU), and IFA patterns were compared using McNemar, Wilcoxon and kappa statistics, respectively. RESULTS:At enrolment, ANA positivity (≥1:80) was 96.1% by IFA1 (median titre 1:1280 (IQR 1:640-1:5120)), 98.3% by IFA2 (1:2560 (IQR 1:640-1:5120)) and 96.6% by ELISA (176.3 AU (IQR 106.4 AU-203.5 AU)). At least one ANA assay was positive for 99.6% of patients at enrolment. At year 5, ANA positivity by IFAs (IFA1 95.2%; IFA2 98.9%) remained high, while there was a decrease in ELISA positivity (91.3%, p<0.001). Overall, there was >91% agreement in ANA positivity at all time points and ≥71% agreement in IFA patterns between IFA1 and IFA2. CONCLUSION/CONCLUSIONS:In recent-onset SLE, three ANA assays demonstrated commutability with a high proportion of positivity and titres or AU. However, over 5 years follow-up, there was modest variation in ANA assay performance. In clinical situations where the SLE diagnosis is being considered, a negative test by either the ELISA or HEp-2 IFA may require reflex testing.

OBJECTIVES/OBJECTIVE:Current treatments are effective only in 30% of lupus nephritis patients emphasizing the need for novel therapeutic strategies. To develop mechanistic hypotheses and explore novel biomarkers, we analyzed the longitudinal urinary proteomic profiles in patients with lupus nephritis undergoing treatment. METHODS:We quantified 1,000 urinary proteins in 30 patients with lupus nephritis at the time of the diagnostic renal biopsy and after 3, 6, and 12 months. The proteins and molecular pathways detected in the urine proteome were then analyzed with respect to baseline clinical features and longitudinal trajectories. The intrarenal expression of candidate biomarkers was evaluated using single cell transcriptomics of renal biopsies from lupus nephritis patients. RESULTS:Our analysis revealed multiple biological pathways including chemotaxis, neutrophil activation, platelet degranulation, and extracellular matrix organization that could be noninvasively quantified and monitored in the urine. We identified 237 urinary biomarkers associated with lupus nephritis as compared to controls without SLE. IL-16, CD163, and TGF-β mirrored intrarenal nephritis activity. Response to treatment was paralleled by a reduction of urinary IL-16, a CD4 ligand with proinflammatory and chemotactic properties. Single cell RNA sequencing independently demonstrated that IL16 is the second most expressed cytokine by most infiltrating immune cells in lupus nephritis kidneys. IL-16 producing cells were found at key sites of kidney injury. CONCLUSION/CONCLUSIONS:Urine proteomics may profoundly change the diagnosis and management of lupus nephritis by noninvasively monitor active intrarenal biological pathways. These findings implicate IL-16 in lupus nephritis pathogenesis designating it as a potentially treatable target and biomarker.

OBJECTIVE:Previous studies suggest a link between high serum type I interferon (IFN) and lupus nephritis (LN). We determined whether serum IFN activity is associated with subtypes of LN and studied renal tissues and cells to understand the impact of IFN in LN. METHODS:). Podocyte cell line gene expression was measured by real-time PCR. RESULTS:expression was not closely co-localized with pDCs. IFN directly activated podocyte cell lines to induce chemokines and proapoptotic molecules. CONCLUSION/CONCLUSIONS:Systemic high IFN is involved in the pathogenesis of severe LN. We do not find co-localization of pDCs with IFN signature in renal tissue, and instead observe the greatest intensity of IFN signature in glomerular areas, which could suggest a blood source of IFN.

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.