Soluble CD25 imposes a low-zone IL-2 signaling environment that favors competitive outgrowth of antigen-experienced CD25high regulatory and memory T cells.

This study focused on soluble (s)CD25-mediated regulation of IL-2 signaling in murine and human CD4+ T cells. Recombinant sCD25 reversibly sequestered IL-2 to limit acute maximal proliferative responses while preserving IL-2 bioavailability to subsequently maintain low-zone IL-2 signaling during prolonged culture. By inhibiting IL-2 signaling during acute activation, sCD25 suppressed T-cell growth and inhibited IL-2-evoked transmembrane CD25 expression, thereby resulting in lower prevalence of CD25high T cells. By inhibiting IL-2 signaling during quiescent IL-2-mediated growth, sCD25 competed with transmembrane CD25, IL2Rßγ, and IL2Rαßγ receptors for limited pools of IL-2 such that sCD25 exhibited strong or weak inhibitory efficacy in IL-2-stimulated cultures of CD25low or CD25high T cells, respectively. Preferential blocking of IL-2 signaling in CD25low but not CD25high T cells caused competitive enrichment of CD25high memory/effector and regulatory FOXP3+ subsets. In conclusion, sCD25 modulates IL-2 bioavailability to limit CD25 expression during acute activation while enhancing CD25highT-cell dominance during low-zone homeostatic IL-2-mediated expansion, thereby 'flattening' the inflammatory curve over time.

Clinical significance of cerebrospinal fluid soluble CD25 in pediatric hemophagocytic lymphohistiocytosis with central nervous system involvement.

OBJECTIVE: To analyze the clinical significance of soluble CD25 (sCD25) levels in cerebrospinal fluid (CSF) in pediatric hemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement. METHODS: All patients diagnosed with HLH admitted to Beijing Children's Hospital, Capital Medical University between January 1, 2017 and October 31, 2021 who received a measurement of their HLH-related parameters and CSF sCD25 levels at admission were enrolled in this study. RESULTS: CSF sCD25 levels in patients with primary HLH were higher than those in patients with Epstein-Barr virus infection-associated HLH, and the median level was 444 pg/ml. The difference in CSF sCD25 levels between the non-CNS group and the CNS group was statistically significant (591 [259-33,643] pg/ml vs. 123 (36-437) pg/ml, p < .001). The best cutoff value of CSF sCD25 was 273.5 pg/ml (AUC = 0.987, 95% CI: 0.972-1.000), with sensitivity, specificity, positive predictive values, and negative predictive values of 96.4%, 92.8%, 81.8%, and 98.7%, respectively. CSF sCD25 in the severe CNS involvement group was significantly higher than that in the nonsevere CNS involvement group (p = .014). The 3-year overall survival (OS) of patients with high CSF sCD25 levels was lower than that of patients with low CSF sCD25 levels(71.6% ± 8.1% vs. 93.3% ± 2.9%, hazard ratio [HR] = 3.637, p = .003). CONCLUSION: Increased CSF sCD25 levels in active disease can predict CNS-HLH. Primary HLH has a higher CSF sCD25 level than Epstein-Barr virus infection-associated HLH. Patients who are diagnosed with CNS-HLH with CSF sCD25 levels higher than 273.5 pg/ml are more likely to develop severe CNS involvement, suggesting a poor prognosis.

Prognostic significance of soluble CD25 in patients with sepsis: a prospective observational study.

OBJECTIVES: The diagnosis of sepsis is challenging, the need for sensitive and specific diagnostic and prognostic biomarkers has not been met. Soluble CD25 (sCD25) is a readily available biomarker reported to represent the severity of the disease. This study aimed to assess the association between sCD25 and mortality in patients with sepsis. METHODS: In total, 329 adult patients with sepsis were screened through a prospective, observational study. We investigated the severity scores and sCD25 levels at admission to the intensive care unit (ICU), defined by sepsis (sepsis-3). The prognostic value of sCD25 was assessed using receiver operating characteristic (ROC) curves and binary logistic regression models in predicting unfavourable outcome. The correlations between variables and severity of disease were analysed by Spearman correlation tests. RESULTS: After entering the ICU, the sCD25 level and sequential organ failure assessment (SOFA) score were significantly higher in nonsurvivors than in survivors. The prognostic values estimated by the ROC curves were 0.678 for sCD25 and 0.945 for SOFA score at ICU admission. sCD25 had a modest ability to predict poor outcome. Logistic regression showed that increased levels of sCD25 were independently associated with unfavourable outcome. Spearman correlation tests showed that sCD25 levels were positively correlated with disease severity. CONCLUSIONS: In sepsis patients, increased sCD25 levels were independently associated with poor clinical outcomes. Further research is needed to improve the understanding of the pathophysiology of this relationship.

High soluble interleukin-2 receptor values in Indian paediatric & adult controls - Need for population-specific threshold in the diagnosis of haemophagocytic lymphohistiocytosis.

Background & objectives: Elevated soluble interleukin-2 receptor (sIL2R) is a diagnostic criterion for haemophagocytic lymphohistiocytosis (HLH). International guidelines propose a 2400 U/ml cut-off or individual laboratory-defined cut-off. However, sIL2R normal values are so far not known in Indians. So, this study was undertaken to measure sIL2R in healthy children and adults to establish age-related reference values. Methods: Healthy controls and cases (participants with persistent fever, organomegaly, cytopenias and biochemical markers of HLH) were prospectively enrolled. Serum sIL2R was measured by double-sandwich enzyme immunoassay in a standardization batch to determine the optimum cut-off value using receiver operator characteristic curve and was subsequently validated. Results: One hundred and forty six age- and sex-matched children (80 controls and 66 suspected HLH cases) and 55 adults (49 controls and 6 suspected HLH cases) were prospectively enrolled. The optimal sIL2R cut-off ≥23 ng/ml was defined as raised sIL2R in the standardization batch. No controls had sIL2R ≥23 ng/ml in the validation batch. In healthy controls, median sIL2R (interquartile range) decreased with increasing age from 9.0 ng/ml (6.6-13.4) below five years of age to 3.2 ng/ml (2.8-5.1) in adults. Proposed upper limit of normal value for sIL2R is 17.4 ng/ml in less than five year, 12.2 ng/ml in 5-9 yr, 6.7 ng/ml in 10-17 yr and 5.2 ng/ml in ≥18 yr. sIL2R accuracy to diagnose HLH marginally improved with age-appropriate cut-off. Interpretation & conclusions: Paediatric controls in India showed higher sIL2R levels than most studies conducted in other countries, except for some reports in Chinese and Russian populations. Age-appropriate reference values of sIL2R in a specific population may be considered to determine elevated sIL2R as a marker of HLH.

A multicenter study of patients with multisystem Langerhans cell histiocytosis who develop secondary hemophagocytic lymphohistiocytosis.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm characterized by the presence of abnormal CD1a-positive (CD1a+ )/CD207+ histiocytes. Hemophagocytic lymphohistiocytosis (HLH) represents a spectrum of hyperinflammatory syndromes typified by the dysregulated activation of the innate and adaptive immune systems. Patients with LCH, particularly those with multisystem (MS) involvement, can develop severe hyperinflammation mimicking that observed in HLH. Nevertheless, to the authors' knowledge, little is known regarding the prevalence, timing, risk factors for development, and outcomes of children and young adults who develop HLH within the context of MS-LCH (hereafter referred to LCH-associated HLH). METHODS: To gain further insights, the authors conducted a retrospective, multicenter study and collected data regarding all patients diagnosed with MS-LCH between 2000 and 2015. RESULTS: Of 384 patients with MS-LCH, 32 were reported by their primary providers to have met the diagnostic criteria for HLH, yielding an estimated 2-year cumulative incidence of 9.3% ± 1.6%. The majority of patients developed HLH at or after the diagnosis of MS-LCH, and nearly one-third (31%) had evidence of an intercurrent infection. Patient age <2 years at the time of diagnosis of LCH; female sex; LCH involvement of the liver, spleen, and hematopoietic system; and a lack of bone involvement each were found to be independently associated with an increased risk of LCH-associated HLH. Patients with MS-LCH who met the criteria for HLH had significantly poorer 5-year survival compared with patients with MS-LCH who did not meet the criteria for HLH (69% vs 97%; P < .0001). CONCLUSIONS: Given its inferior prognosis, further efforts are warranted to enhance the recognition and optimize the treatment of patients with LCH-associated HLH.

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

Objective Serum soluble CD25 (sCD25) could be used as a biomarker for disease activity in conditions associated with T-cell activation including various autoimmune diseases. This study aimed to explore the role of sCD25 as an indicator of disease activity and organ involvement in patients with systemic lupus erythematosus (SLE). Methods Serum samples were collected from 107 SLE patients and 92 age-matched healthy controls (HCs). All patients were followed up for 24 weeks, and sCD25 was measured by enzyme-linked immunosorbent assay. Clinical and laboratory data were recorded at baseline and then every two weeks until week 24. The Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI)-2K was adopted for assessing disease activity at all visits. Results Serum sCD25 levels were significantly increased in SLE patients compared to those in HCs ( p < 0.001). More patients in the high-sCD25 group had lupus nephritis, arthritis and vasculitis ( p = 0.010, p = 0.023 and p = 0.042, respectively). SLEDAI-2K, erythrocyte sedimentation rate, C-reactive protein and 24-hour urinary protein excretion were all associated with high levels of sCD25 ( p < 0.001, p = 0.002, p = 0.038 and p = 0.029, respectively). During the 24-week follow-up, more patients in the high-sCD25 group developed renal impairment (48% vs 6.2%, p = 0.005), and higher levels of sCD25 ( p = 0.033) were found at the time of onset of renal disease. Conclusions Serum sCD25 is a hallmark of disease activity and a predictor of renal disease in patients with SLE.

Pancreatic stone protein and soluble CD25 for infection and sepsis in an emergency department.

BACKGROUND: Infection is a common problem in emergency departments (EDs) and is associated with high mortality, morbidity and costs. Identifying infection in ED patients can be challenging. Biomarkers can facilitate its diagnosis, enabling an early management and improving outcomes. In the critical care setting, two emerging biomarkers, pancreatic stone protein (PSP) and soluble CD25 (sCD25), have demonstrated to be useful for diagnosis of sepsis. We aimed to assess the diagnostic value of these biomarkers, in comparison with procalcitonin (PCT), for infection and sepsis in an ED population with suspected infection. MATERIALS AND METHODS: Through a prospective, observational study, we investigated the utility of serum PCT, PSP and sCD25 levels, measured on admission, for diagnosis of infection and sepsis, defined according to the recently updated for sepsis (Sepsis-3), in patients presenting to the ED for suspected infection. Diagnostic accuracy was evaluated by using receiver operating characteristic curves (ROC) analysis. RESULTS: Of the 152 patients enrolled in this study, 129 had a final diagnosis of infection, including 82 with noncomplicated infection and 47 with sepsis. Median PCT, PSP and sCD25 levels were significantly higher in patients with infection and sepsis. The ROC curve analysis revealed a similar diagnostic accuracy for infection (ROC area under the curve (AUC) PCT: 0·904; sCD25: 0·869 and PSP: 0·839) and for sepsis (ROC AUC: PCT: 0·820; sCD25: 0·835 and PSP: 0·872). CONCLUSIONS: Pancreatic stone protein and sCD25 perform well as infection and sepsis biomarkers, with a similar performance than PCT, in ED patients with suspected infection. Further larger studies investigating use of PSP and sCD25 are needed.

Clinical utility of soluble interleukin-2 receptor in hemophagocytic syndromes: a systematic scoping review.

The serum-soluble interleukin-2 receptor (sIL-2r) level is considered an important diagnostic test and disease marker in hemophagocytic syndromes/hemophagocytic lymphohistiocytosis (HPS/HLH). However, this cytokine receptor is rarely measured in clinical practice and has been excluded from recent diagnostic/classification criteria such as the HScore and macrophage activation syndrome (MAS) 16. We performed a systematic scoping review of 64 articles (1975-2016) examining the clinical utility of sIL-2r in HPS/HLH. Twenty-two articles describe sIL-2r as a sensitive diagnostic marker for HLH, but only three distinct datasets actually address sensitivity. The original HLH-2004 Guidelines reported sensitivity of 93% and specificity of 100% for sIL-2r ≥ 2400, based on a pediatric dataset (n = 152) which is published for the first time in this review. Two pediatric studies reported sensitivity of 89% for sIL-2r ≥ 2400 in diagnosis of MAS complicating juvenile idiopathic arthritis (JIA) (n = 27) and 88% for secondary HLH in acute liver failure (n = 9). Twenty articles described sIL-2r as a dynamic marker of disease activity that falls with response to treatment, and 15 described high initial sIL-2r levels >10,000 U/mL as a poor prognostic marker. The ability of sIL-2r to distinguish between subtypes of HPS/HLH was inconsistent. This review confirms the importance of soluble IL-2r as a diagnostic and disease marker in HPS/HLH, but also reveals the need for more primary data about its performance characteristics, particularly in adults. More emphasis should be made in including this simple, inexpensive test in clinical practice and studies of HPS/HLH.

Soluble CD25 is increased in patients with sepsis-induced acute kidney injury.

AIM: Sepsis has been shown to induce the expansion of CD4+CD25+ regulatory T cells (Tregs), and this paradoxical immune suppression has been suggested to be closely associated with the development of sepsis-induced organ dysfunction. In the present study, we aimed to investigate the possible link between immune suppression and the development of septic acute kidney injury (AKI). METHODS: We prospectively enrolled patients with a diagnosis of sepsis, with or without AKI and as well as patients with AKI but without sepsis. Serum and urine samples at the time of the diagnosis were collected to measure neutrophil gelatinase-associated lipocalin (NGAL), cytokines, and soluble CD25 (sCD25). RESULTS: Of the 82 patients enrolled, 44, 18, and 20 patients were classified into septic-AKI, sepsis-non AKI and non-septic AKI groups. There were no differences in the baseline characteristics in all three groups and the severity of infection in the two sepsis groups. Serum levels of interleukin (IL)-10 were significantly elevated in patients with septic-AKI compared to the other two groups. Serum and urine NGAL levels and the level of serum sCD25, a marker of regulatory T cells, were significantly elevated in patients with septic AKI group, indicating the potential association of paradoxical immune suppression and the development of septic-AKI. CONCLUSIONS: These results suggest that immune suppression in sepsis may be closely linked to the development of AKI and that sCD25 or IL-10 may be useful as novel biomarkers for the development of septic AKI.

A Rare Case of Hemophagocytic Lymphohistiocytosis in an Adult.

This case report involves an adult patient diagnosed with a rare disease, hemophagocytic lymphohistiocytosis (HLH). We will discuss the patient's clinical presentation, symptoms, and treatment. Due to the rarity of HLH being found in adults, we will break down the essential elements to recognize and diagnose this disease. We present this case to increase physician awareness of HLH occurring in adults. With timely recognition, more patients will be able to receive appropriate treatment, resulting in a decrease in mortality.

Evaluation of Biomarkers in Sepsis: High Dimethylarginine (ADMA and SDMA) Concentrations Are Associated with Mortality.

BACKGROUND: As modulators of nitric oxide generation, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) may play important roles in sepsis. Current data on dimethylarginines are conflicting, and direct comparison data with other biomarkers are limited. METHODS: Fifty-five patients were included in the final analysis and were divided into 4 groups: infection without sepsis, sepsis, severe sepsis, and septic shock. The first available samples on hospital admission were analyzed for ADMA, SDMA, procalcitonin (PCT), C-reactive protein, heparin binding protein (HBP), zonulin, soluble CD25 (sCD25), and soluble CD163 (sCD163). White blood cell (WBC) counts and lactate results were obtained from the medical record. RESULTS: There were no statistically significant differences in ADMA and SDMA concentrations among the 4 groups; however, PCT, WBC, HBP, and sCD25 showed statistically significant differences. Lactate only trended toward statistical significance, likely because of limited availability in the medical record. Differences between survivors of sepsis and nonsurvivors at 30 days were highly statistically significant for ADMA and SDMA. Areas under the curve (AUCs) for ROC analysis were 0.88 and 0.95, respectively. There was also a statistically significant difference between survivors of sepsis and nonsurvivors for HBP, lactate, sCD25, and sCD163; however, AUCs for ROC curves were not statistically significantly different from 0.5. CONCLUSIONS: Analysis of biomarkers other than dimethylarginines were in general agreement with expectations from the literature. ADMA and SDMA may not be specific markers for diagnosis of sepsis; however, they may be useful in short-term mortality risk assessment.

High levels of soluble CD25 in COVID-19 severity suggest a divergence between anti-viral and pro-inflammatory T-cell responses.

OBJECTIVES: We aimed to gain an understanding of the paradox of the immunity in COVID-19 patients with T cells showing both functional defects and hyperactivation and enhanced proliferation. METHODS: A total of 280 hospitalised patients with COVID-19 were evaluated for cytokine profiles and clinical features including viral shedding. A mouse model of acute infection by lymphocytic choriomeningitis virus (LCMV) was applied to dissect the relationship between immunological, virological and pathological features. The results from the mouse model were validated by published data set of single-cell RNA sequencing (scRNA-seq) of immune cells in bronchoalveolar lavage fluid (BALF) of COVID-19 patients. RESULTS: The levels of soluble CD25 (sCD25), IL-6, IL-8, IL-10 and TNF-α were higher in severe COVID-19 patients than non-severe cases, but only sCD25 was identified as an independent risk factor for disease severity by multivariable binary logistic regression analysis and showed a positive association with the duration of viral shedding. In agreement with the clinical observation, LCMV-infected mice with high levels of sCD25 demonstrated insufficient anti-viral response and delayed viral clearance. The elevation of sCD25 in mice was mainly contributed by the expansion of CD25+CD8+ T cells that also expressed the highest level of PD-1 with pro-inflammatory potential. The counterpart human CD25+PD-1+ T cells were expanded in BALF of COVID-19 patients with severe disease compared to those with modest disease. CONCLUSION: These results suggest that high levels of sCD25 in COVID-19 patients probably result from insufficient anti-viral immunity and indicate an expansion of pro-inflammatory T cells that contribute to disease severity.

Association of soluble interleukin-2 receptor alpha with laboratory parameters and clinical findings of hemophagocytic lymphohistiocytosis patients: The first report from South of Iran.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is caused by overactivation of immune system. Gene mutations, infections, malignant, and autoimmune trigger the development of the disease. MATERIALS AND METHODS: Clinical data and peripheral blood samples of 21 patients suspected of HLH were collected in Shiraz Medical Centers 2017-2018. Peripheral blood samples were analyzed for soluble interleukin-2 receptor alpha (sIL2Rα) marker (sCD25), and the results were compared with 36 normal controls as well as comparison with clinical findings and other laboratory parameters. RESULTS: Twenty-one patients (11 males and 10 females) with an average age of 5.2 were investigated. In this study, peripheral blood samples were taken from 16 newly diagnosed patients before treatment, and five were posttreatment blood samples. The mean sIL2Rα level before treatment in 16 patients was 9023 pg/ml. The mean peripheral blood sample of the 36 controls was 3025 pg/ml. The mean of the five posttreatment samples was 4198 pg/ml. Significant difference between pretreatment and the control group was observed. However, no significant difference was detected between after treatment samples and the control group. By comparing the sIL2Rα levels between patients with increased aspartate aminotransaminase (AST) and patients with normal AST level, there was a significant difference in the amount of IL2Rα level. CONCLUSION: This study highlights the importance of IL2Rα marker in the diagnosis and follow-up, during treatment and suppression. Furthermore, a significant difference with respect to AST level requires further investigation.

Soluble CD25 as a predictor of hepatocellular carcinoma compared with alpha-fetoprotein.

AIM OF THE STUDY: We aimed to evaluate soluble CD25 (sCD25) as a marker for hepatocellular carcinoma (HCC) diagnosis. MATERIAL AND METHODS: Eighty-eight subjects were enrolled in our study in the years 2017-2018. They were divided into three groups as follows: group 1 - HCC group (n = 44) patients, represented by BCLC stage A (n = 16) patients, stage B (n = 14) patients and stage C (n = 14) patients for each stage. All HCC patients were on top of cirrhosis. Group 2 - group of cirrhotic patients without HCC (n = 32); 50% of them were Child-Turcotte-Pugh class A (n = 16) while class B was represented only by 43.7% (n = 14) of patients. Group 3 - control group (n = 12) of healthy subjects. RESULTS: The levels of sCD25 and AFP were higher in HCC patients than cirrhotic and control groups without a statistically significant difference between the three groups (p-value > 0.05). For HCC presence, sensitivity and specificity of sCD25 were 86.4% and 29.5% respectively at a cut-off value of 1.1 × 103 pg/ml (AUC = 0.619, p-value = 0.054, PPV = 33.2%, NPV = 68.44%). For early detection of HCC, sCD25 had a sensitivity of 70.5% and a specificity of 30.9% at a cut-off value of 1.575 × 103 pg/ml (AUC = 0.577, p-value = 0.251, PPV = 58.5%, NPV = 43.1%), while the sensitivity and specificity of AFP were 75% and 62.5% respectively at a cut-off value of 9.5 ng/ml (AUC = 0.828, p = 0.000, PPV = 73.4%, NPV = 64.4%) in the same settings. CONCLUSIONS: sCD25 seems to offer no better detection rate of HCC compared to AFP with lower sensitivity and specificity.

Development, analytical validation, and initial clinical evaluation of a radioimmunoassay for the measurement of soluble CD25 concentrations in canine serum.

During immune activation, CD25 is expressed by T cells, and its soluble form (sCD25) is released into the extracellular matrix and the bloodstream. In humans, serum sCD25 concentrations are used as a surrogate marker for autoimmune diseases, malignancies, and transplant rejection. However, a canine-specific assay for the measurement of sCD25 in dog serum has not previously been described. Therefore, the aims of this study were to develop and analytically validate a radioimmunoassay to measure sCD25 in canine serum, to establish a reference interval for canine sCD25, and to test the clinical utility of this assay with serum samples for dogs with various diseases. A competitive radioimmunoassay (RIA) was developed and analytically validated. Analytical validation consisted of lower limit of detection (LLOD), dilutional parallelism, spiking recovery, and intra- and inter-assay variability using pooled surplus canine serum samples. A reference interval was established in healthy dogs and serum samples from dogs with various types of neoplasia, IBD, liver disease, suspected pancreatitis, or suspected small intestinal disease and serum samples with an increased C-reactive protein concentration (CRP) were analyzed to test the clinical utility of the assay. LLOD was calculated to be 0.5 ng/mL. The mean (±SD) observed-to-expected ratio (O/E) for serial dilutions was 101.7 ±â€¯14.0%, and the mean (± SD) O/E for spiking recovery was 93.2 ±â€¯4.2%. Coefficients of variation (CVs) for intra-assay variability were ≤12.5% (mean ±â€¯SD: 7.5 ±â€¯4.2%), and inter-assay CVs were ≤15.7% (mean ±â€¯SD: 11 ±â€¯4.4%). A reference interval (RI) for canine sCD25 of 1.2-4.2 ng/mL was established from a population of 112 clinically healthy dogs. Dogs with neoplasia and dogs with suspected small intestinal disease had decreased concentrations of serum sCD25 when compared to healthy dogs (p < 0.0001, respectively). However, the majority of clinical samples used in this study were within the reference interval. Median concentrations of serum sCD25 were 1.9 ng/mL for healthy dogs. Dogs with cancer, IBD, liver disease, suspected pancreatitis, or suspected small intestinal disease, as well as sera with an increased serum CRP concentration, had median serum sCD25 concentrations of 1.6 ng/mL, 2.1 ng/mL, 2.2 ng/mL, 1.7 ng/mL, 1.5 ng/mL, and 1.8 ng/mL, respectively. Thus, the RIA described here is linear, accurate, precise, and reproducible for measuring sCD25 in canine serum. However, this assay shows little clinical utility of sCD25 as a biomarker for dogs with inflammatory, autoimmune, and/or neoplastic conditions.

Utilidad de la Determinación de CD25 Soluble en Pacientes con sospecha de Síndrome de Activación Macrofágica / Usefulness of the determination of soluble CD25 in patients with suspected macrophage activation syndrome

El síndrome de activación macrofágica (SAM) presenta criterios clínicos y de laboratorio establecidos. Presentamos el caso de un adolescente varón con debut de Lupus eritematoso generalizado pediátrico grave, donde su manifestación principal fue un SAM y el receptor de interleucina 2 soluble en suero (IL-2rs) o CD25 soluble (CD25s) aumentado resultó clave en la confirmación diagnóstica, en el tratamiento y pronóstico de su enfermedad. Sin embargo, este receptor de citocinas no se mide habitualmente en la práctica clínica.

Macrophage activation syndrome (MAS) presents established clinical and laboratory criteria. We present the case of a male adolescent with the onset of severe pediatric systemic Lupus erythematosus, manifested mainly by MAS and how a laboratory marker, serum soluble interleukin-2 receptor (IL-2rs) or altered soluble CD25(CD25s), played a key role in treatment and prognosis of the disease. However, this cytokine receptor is rarely measured in clinical practice.

Soluble CD25 in serum: a potential marker for subclinical macrophage activation syndrome in patients with active systemic onset juvenile idiopathic arthritis.

OBJECTIVE: Laboratory and immunological abnormalities seen in overt macrophage activation syndrome (MAS) may be observed in patients with untreated new onset systemic onset juvenile idiopathic arthritis (SoJIA). We investigated the prevalence of clinical and traditional laboratory markers of MAS as well as soluble CD163 and soluble interleukin (IL)-2Rα (CD25) in active SoJIA patients. METHODS: Thirty-three consecutive patients with active SoJIA (International League of Associations for Rheumatology criteria), 11 patients with active polyarticular JIA (polyJIA) (disease control) and two patients with MAS with SoJIA were included in the study. Clinical data, complete blood count, coagulation profile, biochemical tests were performed. Soluble CD25 and soluble CD163 levels were estimated by enzyme-linked immunosorbent assay. RESULTS: Of the 33 active SoJIA patients, 22 were male, the mean age at onset of disease was 6.77 ± 4.48 years and the duration of disease was 4.39 ± 4.6 years. Of the 11 polyJIA patients seven were boys. None of the SoJIA patient had clinical features of MAS. Fibrinogen < 2.5 g/L was present in 14/33 patients with SoJIA but in only 1/11 in polyJIA. Both patients with MAS had thrombocytopenia, leucopenia and reduced fibrinogen levels. sCD25 > 7500 pg/mL seen in MAS was present in eight patients with active SoJIA. Among these eight patients, four had multiple laboratory abnormalities suggestive of MAS. Indeed, one of the patients had past history of MAS. Elevated sCD63 (> 1800 ng/mL) was seen in four patients with SoJIA. CONCLUSION: Laboratory abnormalities associated with MAS are not uncommon in active SoJIA. Soluble CD25 > 7500 pg/mL may be a marker to detect children with subclinical MAS.

Increased proportion of CD4(+)CD25(+)Foxp3(+) regulatory T cells during early-stage sepsis in ICU patients.

BACKGROUND/PURPOSE(S): We investigated whether CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) are induced in patients suffering from early-stage septic shock and distinguish them from noninfectious patients with systemic inflammatory response. METHODS: The study included 37 patients with early-stage septic shock, 15 patients with noninfectious systemic inflammatory response syndrome (SIRS), and 24 heath controls. We prospectively assayed the fraction of Tregs expressing high levels of CD25 and forkhead box P3 (Foxp3) as well as the plasma levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), and soluble CD25 in all the subjects studied. RESULTS: Compared with the control groups, the plasma levels of IFN-γ [66.10 (45.23-85.08) pg/mL vs. 20.97 (17.58-26.21) pg/mL, p < 0.001] and IL-4 [100.69 (77.41-127.68) pg/mL vs. 70.40 (64.14-80.15) pg/mL, p < 0.001] as well as the IFN-γ/IL-4 ratio [0.66 (0.62-0.67) vs. 0.30 (0.27-0.33), p < 0.001] were significantly elevated in the patients with early-stage septic shock, but there was no difference between patients with sepsis and patients with SIRS. We found that the proportion of CD4(+)CD25(+)Foxp3(+) T cells was significantly increased in the patients with early-stage septic shock [(66.82 ± 21.79%) vs. (51.79 ± 21.79%) vs. (56.45 ± 10.68%), p = 0.003] in comparison with the SIRS and control groups, which could be differentiated from the patients with SIRS. The plasma levels of soluble CD25 were also increased, and positively correlated with the proportion of Tregs in patients with early-stage septic shock (Spearman correlation coefficient = 0.390, p = 0.003). CONCLUSION: Our findings indicate that the proportion of CD4(+)CD25(+)Foxp3(+) T cells could be an indicator for the early diagnosis of sepsis. This proportion can also facilitate the evaluation of the patient's immune status and guide suitable immunoregulatory therapy.