Serum soluble CD25 as a risk factor of renal impairment in systemic lupus erythematosus - a prospective cohort study

Joint fluid multi-omics improves diagnostic confidence during evaluation of children with presumed septic arthritis

BACKGROUND

An accurate diagnosis of septic versus reactive or autoimmune arthritis remains clinically challenging. A multi-omics strategy comprising metagenomic and proteomic technologies were undertaken for children diagnosed with presumed septic arthritis to advance clinical diagnoses and care for affected individuals.

METHODS

Twelve children with suspected septic arthritis were prospectively enrolled to compare standard of care tests with a rapid multi-omics approach. The multi-omics combined bacterial 16S rRNA metagenomics, single cell transcriptomics, and proteomics on knee joint fluid specimens. The diagnostic value of the multi-omics was ascertained relative to standard of care culture and PCR-negative results.

RESULTS

Ten children with suspected primary septic arthritis and two with acute hematogenous osteomyelitis (AHO) diagnoses were assessed. Joint fluid bacterial cultures were positive for 6/12 (50%) patients, consistent with elevated inflammatory markers (IL-4, IL-6, IL-17A, TNF-a, etc.). Metagenomic bacterial sequencing results were 100% concordant with the culture results. Six patients were culture- and PCR-negative. Multiomics analyses of the 6 culture negative patients established that 2/6 culture-negative children had inflammatory arthritis with potential Juvenile idiopathic arthritis (JIA) and 1 had post-Streptococcal Reactive Arthritis. The children without any bacteremia had autoantibodies (IgGs) in the joint-fluid targeting several nuclear antigens (i.e., dsDNA, histones, Jo-1, scl-70, Ro/SS-A, SmDs, CENP-A along with non-nuclear antigens i.e. Albumin, Collagens, Myosin, Laminin, etc. Single cell transcriptomics confirmed an abundance of CD4+ follicular helper T (Tfh), CD8 + T cells and B cells in the autoantibody positive subjects. The combination of 16S DNA sequencing (p = 0.006), cytokine assays (p = 0.009) and autoantibody profiling (p = 0.02) were significantly distinct between those children with and without infections. This improved the diagnostic confidence for 9 of 12 (75%) children, key for treatment decisions.

CONCLUSIONS

The multiomics approach rapidly identified children with bacterial or autoimmune inflammatory conditions, improving diagnostic and treatment strategies for those with presumptive septic arthritis.

Soluble TNFR1 has greater reproducibility than IL-6 for the assessment of chronic inflammation in older adults: the case for a new inflammatory marker in aging

Chronic inflammatory pathway activation, commonly referred to as "Inflammaging" or chronic inflammation (CI), is associated with frailty, cognitive and functional decline, and other causes of health span decline in older adults. We investigated the variability of candidate serum measures of CI among community-dwelling older adults selected for mild low-grade inflammation. We focused on serum cytokines known to be highly predictive of adverse health outcomes in older adults (sTNFR1, IL-6) during a short-term (weeks) and medium-term (months) follow-up, as well as immune markers that are less studied in aging but reflect other potentially relevant domains such as adaptive immune activation (sCD25), innate immune activation (sCD14 and sCD163), and the inflammation-metabolism interface (adiponectin/Acrp30) during short-term (weeks) follow up. We found that sTNFR1 was more reproducible than IL-6 over a period of weeks and months short-term and medium-term. The intra-class correlation coefficient (ICC) for sTNFR1 was 0.95 on repeated measures over 6 weeks, and 0.79 on repeated measures with mean interval of 14 weeks, while the ICC for IL-6 was 0.52 over corresponding short-term and 0.67 over corresponding medium-term follow-up. This suggests that sTNFR1 is a more reliable marker of CI than IL-6. This study provides new insights into the reproducibility of serum markers of CI in older adults. The findings suggest that sTNFR1 may be a better marker of CI than IL-6 in this population. Further studies are needed to confirm these findings and to investigate the clinical utility of sTNFR1 in older adults.

Increased serum soluble interleukin-2 receptor levels in dermatomyositis are associated with Th17/Treg immune imbalance

Dermatomyositis (DM) represents a multifaceted chronic inflammatory myopathy, primarily manifesting as progressive deterioration of muscular and cutaneous tissues. Despite an incomplete comprehension of DM's etiology and pathogenesis, current evidence implicates the involvement of T lymphocyte infiltration, extensive cytokine release, myositis-specific antibodies, and myositis-associated antibodies in disease development. Serum soluble interleukin-2 receptor (sIL-2R) frequently serves as a marker for T cell activation; however, its role remains elusive. Consequently, this investigation sought to elucidate the association between sIL-2R levels, peripheral blood lymphocyte subset counts, and related cytokines in DM patients, with the aim of uncovering the intricate mechanisms underlying DM and establishing a theoretical foundation for the implementation of precise, targeted, individualized immunomodulatory therapy. In this study, a cohort of 60 dermatomyositis (DM) patients, comprising 32 with inactive DM and 28 with active DM, was enrolled and stratified into inactive and active groups based on the Myositis Disease Activity Visual Analogue Scale (MYOACT). Flow cytometry was employed to quantify the absolute counts of peripheral lymphocyte subsets and CD4+T cell subsets in each group, while a flow cytometry bead array was utilized to measure serum cytokine levels. In a comparative analysis between healthy individuals and patients diagnosed with DM, we observed a marked elevation in serum sIL-2R concentrations (P < 0.001) and T-helper 17 cell/regulatory T cell (Th17/Treg) ratios (P < 0.01) within the latter group. A positive correlation was identified between serum sIL-2R levels and various parameters, including ESR, CRP, VAS, AST, CKMB, LDH, HBDH, PT, APTT, DDi, IL-6, IL-10, and IFN-γlevels (P < 0.05). In contrast, serum sIL-2R levels demonstrated a negative correlation with LY, HGB, ALB, Th17 cell populations, and Th17/Treg cell ratios (P < 0.05). Employing multivariate logistic regression, we identified serum sIL-2R concentrations as an independent risk factor for both disease activity and hepatic involvement in DM patients. Moreover, receiver operating characteristic (ROC) curve analyses revealed that serum sIL-2R levels significantly contributed to the differentiation of disease activity and the detection of liver involvement in DM patients, with areas under the ROC curve (AUC) of 0.757 (95% CI 0.630-0.884, P = 0.001) and 0.826 (95% CI 0.717-0.935, P < 0.001), respectively. This study highlights the potential utility of serum sIL-2R levels as a valuable biomarker for assessing disease activity and liver involvement in dermatomyositis. Elevated serum concentrations of sIL-2R were observed in patients with DM, exhibiting significant associations with Th17 cell populations and Th17/ Treg ratios. These findings indicate that sIL-2R may be implicated in the immunopathogenesis of DM, thereby warranting further investigation to elucidate its role in the disease process.

Haemoglobin drives inflammation and initiates antigen spread and nephritis in lupus

Haemoglobin (Hb) has well-documented inflammatory effects and is normally efficiently scavenged; clearance mechanisms can be overwhelmed during erythrocyte lysis. Whether Hb is preferentially inflammatory in lupus and triggers broad anti-self responses was assessed. Peripheral blood mononuclear cells (PBMCs) derived from SLE patients secreted higher levels of lupus-associated inflammatory cytokines when incubated with human Hb than did PBMCs derived from healthy donors, an effect negated by haptoglobin. Ferric murine Hb triggered the preferential release of lupus-associated cytokines from splenocytes, B cells, CD4 T cells, CD8 T cells and plasmacytoid dendritic cells isolated from ageing, lupus-prone NZM2410 mice, and also had mitogenic effects on B cells. Pull-downs, followed by mass spectrometry, revealed interactions of Hb with several lupus-associated autoantigens; co-incubation of ferric Hb with apoptotic blebs (structures that contain packaged autoantigens) revealed synergies-in terms of cytokine release and autoantibody production in vitro-that were also restricted to the lupus genotype. Murine ferric Hb activated multiple signalling pathways and, in combination with apoptotic blebs, preferentially triggered MAP kinase signalling specifically in splenocytes isolated from lupus-prone mice. Infusion of murine ferric Hb into lupus-prone mice led to enhanced release of lupus-associated cytokines, the generation of a spectrum of autoantibodies and enhanced-onset glomerulosclerosis. Given that the biased recognition of ferric Hb in a lupus milieu, possibly in concert with lupus-associated autoantigens, triggers inflammatory responses and the generation of lupus-associated cytokines, and also stimulates the generation of potentially pathogenic lupus-associated autoantibodies, neutralization of Hb could have beneficial effects.

Immune Activation and Microbial Translocation as Prognostic Biomarkers for AIDS-Related Non-Hodgkin Lymphoma in the AMC-034 Study

PURPOSE

AIDS-related non-Hodgkin lymphoma (ARL) is the most common cancer in HIV-infected individuals in the United States and other countries in which HIV-positive persons have access to effective combination antiretroviral therapy (cART). Our prior work showed that pretreatment/postdiagnosis plasma levels of some cytokines, such as IL6, IL10, and CXCL13, have the potential to serve as indicators of clinical response to treatment and survival in ARL. The aims of this study were to identify novel prognostic biomarkers for response to treatment and/or survival in persons with ARL, including biomarkers of microbial translocation and inflammation.

EXPERIMENTAL DESIGN

We quantified plasma levels of several biomarkers (sCD14, LBP, FABP2, EndoCab IgM, IL18, CCL2/MCP-1, sCD163, IP-10/CXCL10, TARC/CCL17, TNFα, BAFF/BLyS, sTNFRII, sCD44, and sIL2Rα/sCD25) by multiplexed immunometric assays (Luminex) or ELISA in plasma specimens obtained from ARL patients enrolled in the AMC-034 trial, which compared infusional combination chemotherapy (EPOCH: etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone) with concurrent or sequential rituximab. Plasma was collected prior to the initiation of therapy (n = 57) and after treatment initiation (n = 55).

RESULTS

We found that several biomarkers decreased significantly after treatment, including TNFα, sCD25, LBP, and TARC (CCL17). Moreover, pretreatment plasma levels of BAFF, sCD14, sTNFRII, and CCL2/MCP-1 were univariately associated with overall survival, and pretreatment levels of BAFF, sTNFRII, and CCL2/MCP-1 were also associated with progression-free survival.

CONCLUSIONS

Our results suggest that patients with ARL who responded to therapy had lower pretreatment levels of inflammation and microbial translocation as compared with those who did not respond optimally.

Serum sCD25 Protein as a Predictor of Lack of Long-Term Benefits from Immunotherapy in Non-Small Cell Lung Cancer: A Pilot Study

Prognosis of advanced non-small cell lung carcinoma (NSCLC) is poor. Even though it can improve with anti-PD-1/PD-L1 agents, most patients do not respond to treatment. We hypothesized that the serum soluble form of the unit α of the interleukin-2 receptor (sCD25) could be used as a biomarker of successful immunotherapy in NSCLC. We recruited patients dosed with atezolizumab (n = 42) or pembrolizumab (n = 20) and collected samples at baseline and during the treatment. Levels of sCD25 were quantified with the ELISA kits. Patients with a high sCD25 at baseline (sCD25.0 ≥ 5.99 ng/mL) or/and at the end of the fourth treatment cycle (sCD25.4 ≥ 7.73 ng/mL) progressed faster and lived shorter without the disease progression and serious toxicity. None of the patients with high sCD25 at both time points continued therapy longer than 9.3 months, while almost 40% of patients with low sCD25 were treated for ≥12.3 months. There was a 6.3-times higher incidence of treatment failure (HR = 6.33, 95% CI: 2.10-19.06, p = 0.001) and a 6.5-times higher incidence of progression (HR = 6.50, 95% CI: 2.04-20.73, p = 0.002) in patients with high compared with low sCD25.0 and sCD25.4. Serum levels of sCD25 may serve as a non-invasive biomarker of long-term benefits from the anti-PD-1/PD-L1s in NSCLC.

Biomarkers Associated with Organ-Specific Involvement in Juvenile Systemic Lupus Erythematosus

Juvenile systemic lupus erythematosus (JSLE) is characterised by onset before 18 years of age and more severe disease phenotype, increased morbidity and mortality compared to adult-onset SLE. Management strategies in JSLE rely heavily on evidence derived from adult-onset SLE studies; therefore, identifying biomarkers associated with the disease pathogenesis and reflecting particularities of JSLE clinical phenotype holds promise for better patient management and improved outcomes. This narrative review summarises the evidence related to various traditional and novel biomarkers that have shown a promising role in identifying and predicting specific organ involvement in JSLE and appraises the evidence regarding their clinical utility, focusing in particular on renal biomarkers, while also emphasising the research into cardiovascular, haematological, neurological, skin and joint disease-related JSLE biomarkers, as well as genetic biomarkers with potential clinical applications.

Clinical disease activity and flare in SLE: Current concepts and novel biomarkers

Systemic lupus erythematosus (SLE) is a complex and heterogeneous systemic autoimmune disease associated with innate and adaptive immune dysregulation. SLE occurs primarily in females of childbearing age, with increased prevalence and severity in minority populations. Despite improvements in treatment modalities, SLE patients frequently experience periods of heightened disease activity and flare that can lead to permanent organ damage, increased morbidity, and early mortality. Such outcomes impair quality of life and inflict a significant socioeconomic burden. Predicting changes in SLE disease activity could allow for closer monitoring and preemptive treatment, but existing clinical, demographic and serologic markers have been only modestly predictive. Novel, proactive approaches to clinical disease management are thus critically needed. Panels of blood biomarkers can detect a breadth of immune pathway dysregulation that captures SLE heterogeneity and disease activity. Alterations in the balance of pro-inflammatory and regulatory soluble mediators have been associated with changes in clinical disease activity and are detectable several weeks prior to clinical flare occurrence. A soluble mediator score has been highly predictive of impending flare in both European American and African American SLE patients, and this score does not require a priori knowledge of specific pathway activation in the patient. We review current concepts of disease activity and flare in SLE, focusing on the potential of novel blood biomarkers to characterize and predict changes in disease activity. Measuring the disordered immune response in SLE in this way promises to improve disease management and prevent organ damage in SLE.

Urinary soluble alpha chain of the interleukin-2 receptor as a biomarker of active lupus nephritis in Egyptian children with juvenile systemic lupus erythematosus

Objectives

This study aims to assess the urinary soluble alpha chain of the interleukin-2 receptor (sCD25) concentrations in patients with juvenile systemic lupus erythematosus (JSLE) and to evaluate its validity to be a possible marker of disease activity in patients with lupus nephritis (LN).

Patients and methods

We assessed sCD25 concentrations in urine samples obtained from 53 JSLE patients (15 males, 38 females; median age 11 years; range, 7 to 17 years) and 30 age- and sex-matched apparently healthy controls (10 males, 20 females; median age 10 years; range, 6 to 16 years). Concentrations were normalized according to urinary creatinine excretion. JSLE patients were subjected to clinical examination and assessment of overall disease activity by Systemic Lupus Erythematous Disease Activity Index (SLEDAI), while evaluation of LN activity was preformed using Systemic Lupus International Collaborating Clinics (SLICC) renal activity score.

Results

The JSLE patients had significantly higher normalized urinary sCD25 concentrations compared to the healthy controls (p=0.001). Patients with active LN had significantly higher normalized urinary sCD25 levels than active JSLE patients without LN (p=0.002) and JSLE patients with inactive disease (p<0.001). A significant positive correlation was found between normalized urinary sCD25 concentrations with different activity parameters such as proteinuria (p=0.004), SLEDAI (p<0.001), renal SLEDAI (p<0.001), and SLICC renal activity score (p<0.001). A significant negative correlation was found between urinary sCD25 and complement 3 (p<0.001).

Conclusion

Urinary concentrations of sCD25 were significantly elevated in JSLE patients, particularly in those with active LN. The remarkable association between urinary sCD25 concentrations and different renal disease activity parameters implies that urinary sCD25 can be a beneficial marker to monitor active nephritis in JSLE patients.

Interleukin-2 Deficiency Associated with Renal Impairment in Systemic Lupus Erythematosus

Impaired interleukin-2 (IL-2) production was reported in systemic lupus erythematosus (SLE). The aim of this study was to investigate the clinical relevance of serum IL-2 and therapeutic effects of recombinant IL-2 (rIL-2) in SLE, especially in lupus nephritis (LN). Decreased serum IL-2 was found in patients with active LN (P = 0.014) and correlated with 24-h urine protein excretion (r = -0.281, P = 0.026). Compared with LN patients with decreased levels of serum IL-2, patients with increased levels had better remission rate (P = 0.041). Furthermore, patients with exogenous low-dose IL-2 supplement demonstrated better improved nephritis and higher remission rate (55.56%, P = 0.058) than those with conventional therapy. In addition, the percentages of regulator T (Treg) cells expanded in LN patients with low-dose recombinant human IL-2 treatment (P = 0.007), especially in LN patients achieving remission (P = 0.010). IL-2 deficiency is associated with renal impairment that can be improved by exogenous IL-2 supplement.

Association between the ratio of aryl hydrocarbon receptor (AhR) in Th17 cells to AhR in Treg cells and SLE skin lesions

Skin lesions are typical clinical manifestations of systemic lupus erythematosus (SLE) and the biomarker for predicting SLE skin injury is not clear. We conducted a hospital-based case-control study with aim to explore the predictive value of the ratio of aryl hydrocarbon receptor (AhR) in T helper 17 (Th17) cells to AhR in regulatory T (Treg) cells (AhR ratio) in SLE skin lesions. The clinical and laboratory data were obtained from their medical records, and the AhR relative expression levels were evaluated by reverse transcription-quantitative polymerase chain reaction. Flow cytometry was applied to determine the proportion of AhR-overexpressing cells in Th17 and Treg cells. Pearson's correlation and logistic regression analyses were used to evaluate the association between AhR ratio risk of skin lesions. Results showed that the expression level of AhR in peripheral blood mononuclear cells was increased >3-fold in patients with SLE compared with that in healthy controls. Compared with control group, the percentage of AhR-overexpressing cells to Th17 cells was statistically higher in patients with SLE, whereas no significant difference was observed in the percentage of AhR-overexpressing cells to Treg cells between patients with SLE and control group. AhR ratio was also higher in SLE, and it was negatively correlated with complement 3 while positively correlated with erythrocyte sedimentation rate. In addition, compared with the low-AhR ratio group, more younger SLE patients with skin lesions, ultraviolet allergies and lower C3 levels were observed in the high-AhR ratio group, implicating that AhR ratio may be a potential biomarker for predicting SLE skin injury.