Usefulness of soluble CD163 as a biomarker for macrophage activation syndrome associated with systemic lupus erythematosus

Early identification of macrophage activation syndrome secondary to systemic lupus erythematosus with machine learning

OBJECTIVE

The macrophage activation syndrome (MAS) secondary to systemic lupus erythematosus (SLE) is a severe and life-threatening complication. Early diagnosis of MAS is particularly challenging. In this study, machine learning models and diagnostic scoring card were developed to aid in clinical decision-making using clinical characteristics.

METHODS

We retrospectively collected clinical data from 188 patients with either SLE or the MAS secondary to SLE. 13 significant clinical predictor variables were filtered out using the Least Absolute Shrinkage and Selection Operator (LASSO). These variables were subsequently utilized as inputs in five machine learning models. The performance of the models was evaluated using the area under the receiver operating characteristic curve (ROC-AUC), F1 score, and F2 score. To enhance clinical usability, we developed a diagnostic scoring card based on logistic regression (LR) analysis and Chi-Square binning, establishing probability thresholds and stratification for the card. Additionally, this study collected data from four other domestic hospitals for external validation.

RESULTS

Among all the machine learning models, the LR model demonstrates the highest level of performance in internal validation, achieving a ROC-AUC of 0.998, an F1 score of 0.96, and an F2 score of 0.952. The score card we constructed identifies the probability threshold at a score of 49, achieving a ROC-AUC of 0.994 and an F2 score of 0.936. The score results were categorized into five groups based on diagnostic probability: extremely low (below 5%), low (5-25%), normal (25-75%), high (75-95%), and extremely high (above 95%). During external validation, the performance evaluation revealed that the Support Vector Machine (SVM) model outperformed other models with an AUC value of 0.947, and the scorecard model has an AUC of 0.915. Additionally, we have established an online assessment system for early identification of MAS secondary to SLE.

CONCLUSION

Machine learning models can significantly improve the diagnostic accuracy of MAS secondary to SLE, and the diagnostic scorecard model can facilitate personalized probabilistic predictions of disease occurrence in clinical environments.

Heterogeneity of macrophage activation syndrome and treatment progression

Macrophage activation syndrome (MAS) is a rare complication of autoimmune inflammatory rheumatic diseases (AIIRD) characterized by a progressive and life-threatening condition with features including cytokine storm and hemophagocytosis. Predisposing factors are typically associated with microbial infections, genetic factors (distinct from typical genetically related hemophagocytic lymphohistiocytosis (HLH)), and inappropriate immune system overactivation. Clinical features include unremitting fever, generalized rash, hepatosplenomegaly, lymphadenopathy, anemia, worsening liver function, and neurological involvement. MAS can occur in various AIIRDs, including but not limited to systemic juvenile idiopathic arthritis (sJIA), adult-onset Still's disease (AOSD), systemic lupus erythematosus (SLE), Kawasaki disease (KD), juvenile dermatomyositis (JDM), rheumatoid arthritis (RA), and Sjögren's syndrome (SS), etc. Although progress has been made in understanding the pathogenesis and treatment of MAS, it is important to recognize the differences between different diseases and the various treatment options available. This article summarizes the cell types and cytokines involved in MAS-related diseases, the heterogeneity, and treatment options, while also comparing it to genetically related HLH.

sCD163, sCD28, sCD80, and sCTLA-4 as soluble marker candidates for detecting immunosenescence

BACKGROUND

Inflammaging, the characteristics of immunosenescence, characterized by continuous chronic inflammation that could not be resolved. It is not only affect older people but can also occur in young individuals, especially those suffering from chronic inflammatory conditions such as autoimmune disease, malignancy, or chronic infection. This condition led to altered immune function and as consequent immune function is reduced. Detection of immunosenescence has been done by examining the immune risk profile (IRP), which uses flow cytometry. These tests are not always available in health facilities, especially in developing countries and require fresh whole blood samples. Therefore, it is necessary to find biomarkers that can be tested using stored serum to make it easier to refer to the examination. Here we proposed an insight for soluble biomarkers which represented immune cells activities and exhaustion, namely sCD163, sCD28, sCD80, and sCTLA-4. Those markers were reported to be elevated in chronic diseases that caused early aging and easily detected from serum samples using ELISA method, unlike IRP. Therefore, we conclude these soluble markers are beneficial to predict pathological condition of immunosenescence.

AIM

To identify soluble biomarkers that could replace IRP for detecting immunosenescence.

CONCLUSION

Soluble costimulatory molecule suchsCD163, sCD28, sCD80, and sCTLA-4 are potential biomarkers for detecting immunosenescence.

Analyzing the pathogenesis of systemic lupus erythematosus complicated by atherosclerosis using transcriptome data

Background

Accumulating evidence supports the predisposition of systemic lupus erythematosus (SLE) to atherosclerosis (AS). However, the common pathogenesis of these two diseases remains unclear. This study aimed to explore the mechanisms of SLE complicated by AS.

Methods

Gene expression profiles of SLE (GSE50772) and AS (GSE100927) were downloaded from the Gene Expression Omnibus. We analyzed differentially expressed genes (DEGs) of SLE and AS and performed enrichment analyses separately. After analyzing the common DEGs (CDEGs), we performed functional enrichment analysis, protein-protein interaction (PPI) network analysis, and hub genes (HGs) identification of CDEGs. Then, we performed a co-expression analysis of HGs and verified their expression and diagnostic value. We further explored immune cell infiltration and analyzed the correlation between HGs and infiltrating immune cells (IICs). Finally, we verified the reliability of the screening pathway.

Results

We obtained 530 DEGs from the GSE50772 dataset and 448 DEGs from the GSE100927 dataset. The results of the enrichment analysis showed that there were many similar immune- and inflammation-related processes between the two diseases. We analyzed 26 CDEGs (two downregulated genes and 24 upregulated genes) and enrichment analysis highlighted the important role of the IL-17 signaling pathway. We identified five HGs (CCR1, CD163, IL1RN, MMP9, and SIGLEC1) using the CytoHubba plugin and HGs validation showed that the five HGs screened were reliable. Co-expression networks showed that five HGs can affect mononuclear cell migration. Immune cell infiltration analysis indicated monocytes in SLE and M0 macrophages in AS accounted for a high proportion of all IICs, and the difference in infiltration was obvious. We also found a significant positive correlation between CCR1, CD163, IL1RN, and MMP9 and monocytes in SLE, and a significant positive correlation between CCR1, IL1RN, MMP9, and SIGLEC1 and M0 macrophages in AS. Pathway validation also demonstrated that the IL-17 signaling pathway was a key pathway for the differentiation of monocytes into macrophages.

Conclusions

The five HGs may promote the differentiation of monocytes into macrophages by influencing the IL-17 signaling pathway, leading to SLE complicated by AS. Our study provides insights into the mechanisms of SLE complicated by AS.

Urine Soluble CD163 Is a Promising Biomarker for the Diagnosis and Evaluation of Lupus Nephritis

Introduction

Urine-soluble CD163 (usCD163) is released from alternatively activated macrophages involved in the resolution of inflammation in glomeruli and plays an important role in glomerulonephritis. This study explored the role of usCD163 in patients with systemic lupus erythematosus (SLE).

Materials and Methods

usCD163 concentrations were measured cross-sectionally in 261 SLE patients in Taiwan. Clinical and laboratory data were collected, and SLE disease activity scores were calculated to assess the correlation with usCD163.

Results

SLE patients with high usCD163 levels tended to be younger, with a higher hospital admission rate, higher prednisolone dose, lower estimated glomerular filtration rate, higher urine protein creatinine ratio (UPCR), more pyuria and hematuria, higher levels of inflammatory markers, higher rates of anemia, neutropenia, and lymphopenia, lower complement 3 (C3) levels, higher anti-double-stranded DNA antibody (anti-dsDNA Ab) levels, and higher disease activity scores (p < 0.05). usCD163 levels were significantly higher in patients with active lupus nephritis (LN) than in those with extrarenal or inactive SLE and correlated with UPCR, disease activity, and anti-dsDNA Ab levels. SLE patients with high usCD163 levels tended to have a higher chronic kidney disease stage.

Discussion and conclusion

The usCD163 level correlates with the severity of LN and disease activity in renal SLE.

Macrophage Polarization and Plasticity in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that attacks almost every organ. The condition mostly happens to adults but is also found in children, and the latter have the most severe manifestations. Among adults, females, especially non-Caucasian, are mostly affected. Even if the etiology of SLE remains unclear, studies show a close relation between this disease and both genetics and environment. Despite the large number of published articles about SLE, we still do not have a clear picture of its pathogenesis, and no specific drug has been found to treat this condition effectively. The implication of macrophages in SLE development is gaining ground, and studying it could answer these gaps. Indeed, both in vivo and in vitro studies increasingly report a strong link between this disease and macrophages. Hence, this review aims to explore the role of macrophages polarization and plasticity in SLE development. Understanding this role is of paramount importance because in-depth knowledge of the connection between macrophages and this systemic disease could clarify its pathogenesis and provide a foundation for macrophage-centered therapeutic approaches.

Elevated soluble CD163 predicts renal function deterioration in lupus nephritis: a cohort study in Eastern China

Objective

This study investigated the association between soluble scavenger receptor differentiation antigen 163 (sCD163) and the severity and prognosis of renal injury in lupus nephritis (LN).

Methods

Serum sCD163 levels in 121 Eastern Chinese patients with LN who underwent renal biopsy were determined by enzyme-linked immunosorbent assays. Clinical data were collected, and the glomerular filtration rate and disease activity score of lupus were calculated. Pathological classification was performed, and renal pathological scores were assessed by the activity index (AI) and chronic index (CI). Kaplan–Meier survival curves were drawn to evaluate prognosis.

Results

The pathological classification, AI and CI scores in the high sCD163 group were increased. The sCD163 levels were positively correlated with serum creatinine, blood urea nitrogen, AI scores and CI scores and negatively correlated with the estimated glomerular filtration rate. Kaplan–Meier survival analysis showed that the incidence of renal endpoint events was increased in the high sCD163 group compared with the normal sCD163 group.

Conclusion

The serum sCD163 level correlates with the severity of LN and is an important indicator of poor renal prognosis in patients with LN.

Quantitative analysis of the blood transcriptome of young healthy pigs and its relationship with subsequent disease resilience

Background

Disease resilience, which is the ability of an animal to maintain performance under disease, is important for pigs in commercial herds, where they are exposed to various pathogens. Our objective was to investigate population-level gene expression profiles in the blood of 912 healthy F1 barrows at ~ 27 days of age for associations with performance and health before and after their exposure to a natural polymicrobial disease challenge at ~ 43 days of age.

Results

Most significant (q < 0.20) associations of the level of expression of individual genes in blood of young healthy pigs were identified for concurrent growth rate and subjective health scores prior to the challenge, and for mortality, a combined mortality-treatment trait, and feed conversion rate after the challenge. Gene set enrichment analyses revealed three groups of gene ontology biological process terms that were related to disease resilience: 1) immune and stress response-related terms were enriched among genes whose increased expression was unfavorably associated with both pre- and post-challenge traits, 2) heme-related terms were enriched among genes that had favorable associations with both pre- and post-challenge traits, and 3) terms related to protein localization and viral gene expression were enriched among genes that were associated with reduced performance and health traits after but not before the challenge.

Conclusions

Gene expression profiles in blood from young healthy piglets provide insight into their performance when exposed to disease and other stressors. The expression of genes involved in stress response, heme metabolism, and baseline expression of host genes related to virus propagation were found to be associated with host response to disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07912-8.

Do COVID-19 Infections Result in a Different Form of Secondary Hemophagocytic Lymphohistiocytosis

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.

Steroid treatment promotes an M2 anti-inflammatory macrophage phenotype in childhood lupus nephritis

BACKGROUND

M1-type proinflammatory macrophages (MΦ) promote glomerular injury in lupus nephritis (LN). However, whether this phenotype is altered by steroid therapy is unclear. Therefore, we investigated the effect of steroid treatment on MΦ phenotype in LN.

METHODS

Patients with LN (7-18 years old) were divided into 2 groups: those with no treatment (N) before biopsy (n = 17) and those who underwent steroid (S) treatment (3-73 days) before biopsy (n = 15). MΦ number and phenotype were assessed by immunofluorescence. In vitro studies used monocyte-derived MΦ from healthy volunteers.

RESULTS

Age at biopsy, urine findings, and kidney function (eGFR) were comparable between the two groups. Biopsies in N group had higher levels of active lesions such as endocapillary hypercellularity, necrosis, and cellular crescent formation (p < 0.05). The total CD68+ MΦ infiltrate was comparable between N and S groups. However, N group had more M1 MΦ (CD68+ CD86+ cells) (p < 0.05) and fewer M2 MΦ (CD68+ CD163+ cells) (p < 0.05), giving a 6-fold increase in the M2/M1 ratio in S vs. N groups. Dexamethasone treatment of cultured MΦ induced upregulation of CD163 expression, increased production of anti-inflammatory (IL-10, IL-19) and profibrotic factors (FGF-22, PDGF), and upregulated the scavenger receptor, stabilin-1. Upregulation of stabilin-1 in CD163+ M2 MΦ was confirmed in biopsies from S group.

CONCLUSIONS

Initial steroid treatment induces MΦ phenotypic change from proinflammatory M1 to anti-inflammatory or profibrotic M2 in LN with acute/active lesions. Although steroid treatment is effective for resolution of M1-medated injury, promotion of fibrotic lesions via M2 MΦ is a potential downside of steroid single therapy in LN.

Macrophage activation syndrome in systemic lupus erythematosus and systemic-onset juvenile idiopathic arthritis: a retrospective study of similarities and dissimilarities

Macrophage activation syndrome (MAS) is a serious complication of rheumatic diseases. Fever and hyperferritinemia are common in active systemic-onset juvenile idiopathic arthritis (sJIA) and cytopenia in active systemic lupus erythematosus (SLE), thus recognizing MAS in them is a challenge. We compared clinical and laboratory parameters, various classification criteria, and outcomes of MAS in SLE and sJIA. Clinical and laboratory data were extracted from case records of patients with clinician diagnosed cases of SLE-MAS (adult and pediatric) and sJIA-MAS, admitted (2004-2018) at a tertiary care hospital. Ravelli, International consensus, HLH-2004, and criteria proposed by Parodi et al. were applied and compared. Among 33 patients (18 females) with MAS, 19 had SLE (7, childhood-onset SLE) and 14 had sJIA. MAS was more likely to be the presenting manifestation of disease in SLE (p < 0.05). There were no differences in the clinical features among them. Patients with SLE-MAS had lower baseline total leucocyte and platelet counts (p < 0.01), whereas patients with sJIA-MAS had significantly higher median CRP (p = 0.002), fall in TLC (p = 0.012), delta ESR/CRP ratio (p = 0.02), and lower fibrinogen level (p = 0.006). Neutrophil-to-lymphocyte ratio, ferritin/CRP ratio, and the number of patients with ferritin/ESR > 80 were similar. Only 6/33(18%) fulfilled the HLH criteria. Criteria meant for sJIA-MAS or SLE-MAS performed well for both diseases and the majority of patients could be diagnosed using them. Two patients died in each group. MAS in SLE and sJIA is more similar than dissimilar in clinical features and outcome. Criteria meant for MAS in sJIA or SLE-MAS performed equally well in both diseases.

Monitoring immunomodulation in patients with sepsis

Introduction: This review aims to summarize current progress of the last ten years in the development of biomarkers used for classifying the immune response of the septic host and for monitoring the efficacy of the applied adjunctive immunotherapy.Areas covered: An extensive search of the literature was performed. In this review the authors discuss available biomarkers of host immune response in sepsis toward two directions; immunosuppression and hyperinflammation. Ferritin, sCD163, sIL-2 ra, and IL-18 may help in the diagnosis of macrophage activation syndrome (MAS) complicating sepsis whereas lymphopenia, decreased HLA-DR expression on monocytes, overexpression of Programmed cell death protein-1 (PD-1)/Programmed death-ligand 1 (PD-L1) and IL-10 are indicators of sepsis-induced immunosuppression. Novel approaches in the classification of immune state in sepsis include Myeloid-Derived Suppressor Cells (MDSC) and specific endotypes, defined by gene expression and molecular techniques.Expert opinion: HLA-DR and ferritin are the most commonly used biomarkers to monitor immunomodulation in clinical practice whereas developing specific sepsis endotypes is the future target. New immunotherapy trials in sepsis need to incorporate biomarkers for a personalized treatment.

Serum changes in sTWEAK and its scavenger receptor sCD163 in ultramarathon athletes running the 24-h race

In the present investigation, the serum changes of sTWEAK levels, a multifunctional cytokine involved in tissue response to acute injury and inflammation, and of its scavenger receptor sCD163, were monitored for the first time in ultramarathon athletes running the 24-h competition, an extremely demanding race in terms of muscular and physiological exertion. To this aim, venous blood samples were collected from each participant (n = 22, M = 12, F = 10) both before and immediately after the 24-h running. Other than sTWEAK and sCD163, the common serum biomarkers of inflammation (namely CRP and IL-6) and tissue injury (such as CPK, LDH, CPK-MB, troponin-I, and NT-proBNP) were evaluated. All parameters were within the reference ranges at baseline, indicating no alterations of the normal physiological processes before the competition; on the contrary, most biomarkers of tissue damage and inflammation strongly increased after the ultramarathon race. Interestingly, a significant decrement of sTWEAK levels associated with an increment of its scavenger receptor sCD163 was observed at post-race. Positive relationships were evidenced between IL-6 and sCD163 levels and the markers of cardiac damage troponin-I and NT-proBNP. On the contrary, sTWEAK showed an inverse correlation with IL-6 and NT-proBNP. This study opens the way to further investigations aimed at clarifying the role of TWEAK pathway during the prolonged ultraendurance activity, paying particular attention to the link of IL-6, CD163 and TWEAK with the cardiac function.

Lupus miliaris disseminatum faciei in a patient with systemic lupus erythematosus and Sjögren's syndrome

We herein report a rare case of lupus miliaris disseminatus faciei on the chin and neck in a patient with systemic lupus erythematosus and Sjögren's syndrome. Histopathological features showed focal aggregates of epithelioid granulomas accompanied by mononuclear cell infiltration in the upper dermis. Immunohistological examination showed enhanced expression of CD68 and CD163. Recent findings have implicated a key role of innate immunity in the pathogenesis of systemic lupus erythematosus, and alteration in M1 and M2 macrophage profile has been suggested. Increased expression of CD163 in the affected skin and other organs, and elevated serum levels of soluble CD163, are reported in systemic lupus erythematosus. Our results may suggest that activated M2 macrophages participated in the induction of lupus miliaris disseminatus faciei in a patient with systemic lupus erythematosus and Sjögren's syndrome.

Urinary soluble CD163 is a good biomarker for renal disease activity in lupus nephritis

OBJECTIVES

Activated macrophages expressing CD163 (M2) are the most abundant macrophage subtype in renal biopsies from lupus nephritis (LN) patients. We studied the role of proteolytically cleaved soluble CD163 (sCD163) as a biomarker of LN disease activity.

METHODS

SLE patients were classified as active LN (AN), inactive disease (ID), and active non-renal disease (ANR). Urine and plasma samples were collected at baseline from all patients and at 3 monthly follow-up from AN patients. sCD163 was measured by ELISA. Urine values were normalized to urinary creatinine excretion and expressed as pg/mg. Urine samples from 25 healthy controls (HC) and 20 rheumatoid arthritis patients served as disease controls (DC).

RESULTS

Among the 122 patients studied (114 females, 57 AN, 42 ID, 23 ANR), baseline median urinary sCD163 in the AN group (114.01 pg/mg) was significantly higher (p < 0.001) as compared with ID (10.34 pg/mg), ANR (3.82 pg/mg), HC (0 pg/mg), and DC (7.56 pg/mg) groups and showed modest correlation with renal SLEDAI (r = 0.47; p < 0.001). Urinary sCD163 performed the best on receiver operating characteristics (ROC) analysis (AUC = 0.76) at baseline to differentiate between AN and ANR as compared with plasma sCD163, anti-ds DNA antibodies, and C3 and C4. In follow-up study, urinary sCD163 decreased significantly (p < 0.001) in AN patients at 3 (22.07 pg/mg), 6 (12.7 pg/mg), 9 (11.09 pg/mg), and 12 months (7.2 pg/mg). In 4 patients who had either relapse or developed CKD, urinary sCD163 levels correlated with the changing disease activity.

CONCLUSIONS

Urinary sCD163 is a good biomarker of LN disease activity. Key Points • Urinary sCD163 levels are raised in patients with active lupus nephritis and correlate with renal SLEDAI. • Urinary sCD163 levels fall after treatment and may be helpful in monitoring response to therapy in lupus nephritis.

COVID-19 as part of the hyperferritinemic syndromes: the role of iron depletion therapy

SARS-CoV-2 infection is characterized by a protean clinical picture that can range from asymptomatic patients to life-threatening conditions. Severe COVID-19 patients often display a severe pulmonary involvement and develop neutrophilia, lymphopenia, and strikingly elevated levels of IL-6. There is an over-exuberant cytokine release with hyperferritinemia leading to the idea that COVID-19 is part of the hyperferritinemic syndrome spectrum. Indeed, very high levels of ferritin can occur in other diseases including hemophagocytic lymphohistiocytosis, macrophage activation syndrome, adult-onset Still's disease, catastrophic antiphospholipid syndrome and septic shock. Numerous studies have demonstrated the immunomodulatory effects of ferritin and its association with mortality and sustained inflammatory process. High levels of free iron are harmful in tissues, especially through the redox damage that can lead to fibrosis. Iron chelation represents a pillar in the treatment of iron overload. In addition, it was proven to have an anti-viral and anti-fibrotic activity. Herein, we analyse the pathogenic role of ferritin and iron during SARS-CoV-2 infection and propose iron depletion therapy as a novel therapeutic approach in the COVID-19 pandemic.

Targeting of CD163+ Macrophages in Inflammatory and Malignant Diseases

The macrophage is a key cell in the pro- and anti-inflammatory response including that of the inflammatory microenvironment of malignant tumors. Much current drug development in chronic inflammatory diseases and cancer therefore focuses on the macrophage as a target for immunotherapy. However, this strategy is complicated by the pleiotropic phenotype of the macrophage that is highly responsive to its microenvironment. The plasticity leads to numerous types of macrophages with rather different and, to some extent, opposing functionalities, as evident by the existence of macrophages with either stimulating or down-regulating effect on inflammation and tumor growth. The phenotypes are characterized by different surface markers and the present review describes recent progress in drug-targeting of the surface marker CD163 expressed in a subpopulation of macrophages. CD163 is an abundant endocytic receptor for multiple ligands, quantitatively important being the haptoglobin-hemoglobin complex. The microenvironment of inflammation and tumorigenesis is particular rich in CD163⁺ macrophages. The use of antibodies for directing anti-inflammatory (e.g., glucocorticoids) or tumoricidal (e.g., doxorubicin) drugs to CD163⁺ macrophages in animal models of inflammation and cancer has demonstrated a high efficacy of the conjugate drugs. This macrophage-targeting approach has a low toxicity profile that may highly improve the therapeutic window of many current drugs and drug candidates.