Evaluation serum soluble interleukin 2 receptor with diagnosis and prognosis in canine solid tumour: 34 cases.

BACKGROUND/AIM: The soluble interleukin-2 receptor (sIL-2R) serve as a valuable biomarker for tumors in human patients, as its levels increase during the activation of T lymphocytes in clinical states such as inflammation, infection, and tumor. This study aimed to demonstrate that sIL-2R levels can be also elevated in dogs with tumors and evaluate its applicability as a diagnostic and prognostic factor in canine cancer patients. PATIENTS AND METHODS: Serum was collected from 6 healthy dogs and 34 dogs with solid tumors. The concentration of sIL-2R was measured using a commercial enzyme-linked immunosorbent assay kit. RESULTS: The median sIL-2R concentration was significantly higher in dogs with solid masses than in healthy dogs (117.3 vs 68.33 pg/ml, p = 0.016). The highest median sIL-2R concentration was found in dogs with malignant tumors, followed by those with benign tumors, and healthy dogs (119.6 vs 93.74 vs 68.33 pg/ml, respectively). In dogs with malignant tumors, the mortality rate was significantly higher in the group with high sIL-2R levels than in the group with low sIL-2R levels. Dogs with solid tumors, particularly those with malignant tumors, had higher concentrations of sIL-2R than healthy dogs. Among dogs with malignant tumors, a correlation between sIL-2R concentration and mortality rate was confirmed. CONCLUSION: Serum sIL-2R levels may be used to detect malignant tumors and serve as a prognostic factor in dogs with malignant tumors.

Development of a highly sensitive platform for protein-protein interaction detection and regulation of T cell function.

We developed a highly sensitive assay for detecting protein-protein interaction using chimeric receptors comprising two molecules of interest in the extracellular domain and interferon alpha and beta receptor subunit 1 or 2 (IFNAR1/2) in the intracellular domain. This intracellular IFNAR1/2 reconstitution system (IFNARRS) proved markedly more sensitive than the NanoBiT system, currently considered one of the best detection systems for protein interaction. Employing chimeric receptors with extracellular domains from the IFNγ or IL-2 receptor and the intracellular domains of IFNAR1/2, the IFNARRS system effectively identifies low IFNγ or IL-2 levels. Cells stably expressing these chimeric receptors responded to IFNγ secreted by activated T cells following various stimuli, including a specific peptide-antigen. The activation signals were further enhanced by the expression of relevant genes, such as costimulators, via IFN-stimulated response elements in the promoters. Besides IFNγ or IL-2, the IFNARRS system demonstrated the capability to detect other cytokines by using the corresponding extracellular domains from these target cytokine receptors.

A novel scoring system based on sIL-2R for predicting IVIG resistance in Chinese children with KD.

OBJECTIVE: This study aimed to develop a novel scoring system utilizing circulating interleukin (IL) levels to predict resistance to intravenous immunoglobulin (IVIG) in Chinese patients with Kawasaki disease (KD). We further compared this scoring system against six previously established scoring methods to evaluate its predictive performance. METHODS: A retrospective analysis was conducted on KD patients who were treated at the cardiovascular medical ward of our institution from January 2020 to December 2022. Six scoring systems (Egami, Formosa, Harada, Kobayashi, Lan and Yang) were analyzed, and a new scoring system was developed based on our data. RESULTS: In our study, 521 KD patients were recruited, 42 of whom (8.06%) were identified as resistant to IVIG. Our study indicated that IVIG-resistant KD patients were at an increased risk for the development of coronary arterial lesions (CALs) (P = 0.001). The evaluation of IVIG resistance using various scoring systems revealed differing levels of sensitivity and specificity, as follows: Egami (38.10% and 88.52%), Formosa (95.24% and 41.13%), Harada (78.57% and 43.22%), Kobayashi (66.67% and 74.95%), Lan (66.67% and 73.49%), and Yang (69.05% and 77.24%). Our novel scoring system utilizing sIL-2R demonstrated the highest sensitivity and specificity of 69.29% and 83.91%, respectively, and calibration curves indicated a favorable predictive accuracy of the model. CONCLUSION: Our newly developed scoring system utilizing sIL-2R demonstrated superior predictive performance in identifying IVIG resistance among Chinese patients with KD.

Peroxynitrite reduces Treg cell expansion and function by mediating IL-2R nitration and aggravates multiple sclerosis pathogenesis.

T-helper 17 cells and regulatory T cells (Treg) are critical regulators in the pathogenesis of multiple sclerosis (MS) but the factors affecting Treg/Th17 balance remains largely unknown. Redox balance is crucial to maintaining immune homeostasis and reducing the severity of MS but the underlying mechanisms are unclear yet. Herein, we tested the hypothesis that peroxynitrite, a representative molecule of reactive nitrogen species (RNS), could inhibit peripheral Treg cells, disrupt Treg/Th17 balance and aggravate MS pathology by inducing nitration of interleukin-2 receptor (IL-2R) and down-regulating RAS/JNK-AP-1 signalling pathway. Experimental autoimmune encephalomyelitis (EAE) mouse model and serum samples of MS patients were used in the study. We found that the increases of 3-nitrotyrosine and IL-2R nitration in Treg cells were coincided with disease severity in the active EAE mice. Mechanistically, peroxynitrite-induced IL-2R nitration down-regulated RAS/JNK signalling pathway, subsequently impairing peripheral Treg expansion and function, increasing Teff infiltration into the central nerve system (CNS), aggravating demyelination and neurological deficits in the EAE mice. Those changes were abolished by peroxynitrite decomposition catalyst (PDC) treatment. Furthermore, transplantation of the PDC-treated-autologous Treg cells from donor EAE mice significantly decreased Th17 cells in both axillary lymph nodes and lumbar spinal cord, and ameliorated the neuropathology of the recipient EAE mice. Those results suggest that peroxynitrite could disrupt peripheral Treg/Th17 balance, and aggravate neuroinflammation and neurological deficit in active EAE/MS pathogenesis. The underlying mechanisms are related to induce the nitration of IL-2R and inhibit the RAS/JNK-AP-1 signalling pathway in Treg cells. The study highlights that targeting peroxynitrite-mediated peripheral IL-2R nitration in Treg cells could be a novel therapeutic strategy to restore Treg/Th17 balance and ameliorate MS/EAE pathogenesis. The study provides valuable insights into potential role of peripheral redox balance in maintaining CNS immune homeostasis.

Beyond biopsy for neurosarcoidosis: A review of blood and CSF biomarkers.

Neurosarcoidosis, a rare granulomatous disease, causes inflammation and damage to the central nervous system (CNS). A major diagnostic challenge in neurosarcoidosis is the absence of well-defined biomarkers. The need for biopsy to make the diagnosis can lead to delays and misdiagnosis if histopathology is inaccessible or indeterminate, highlighting the need for more accessible diagnostic indicators. The current gold standard for a "definite" neurosarcoidosis diagnosis requires biopsy of CNS tissue revealing non-caseating granulomas. However, such biopsies are inherently invasive and carry associated procedural risks. Notably, angiotensin-converting enzyme (ACE), commonly associated with systemic sarcoidosis, is recognized as a poor biomarker for neurosarcoidosis due to its lack of accuracy in the context of CNS involvement. Furthermore, imaging in neurosarcoidosis, while widely utilized and important for narrowing the diagnosis, lacks specificity. Decades of research have yielded molecular and immunologic biomarkers-soluble interleukin-2 receptor (IL-2R), serum amyloid A1, the CD4/CD8 ratio, neopterin, interferon-gamma (IFN-γ), and chemokine ligand 2 (CCL2)-that hold potential for improving diagnostic accuracy. However, these biomarkers are not yet established in clinical care as they may be difficult to obtain and are derived from small studies. They also suffer from a lack of specificity against other inflammatory and infectious central nervous system diseases. New biomarkers are needed for use alongside those previously discovered to improve diagnosis of this rare disease. This review synthesizes existing literature on neurosarcoidosis biomarkers, aiming to establish a foundation for further research in this evolving field. It also consolidates information on biomarkers of systemic sarcoidosis such as IL-8 and soluble CD40L that have not yet been studied in neurosarcoidosis but hold potential as markers of CNS disease.

Dynamic Foxp3-chromatin interaction controls tunable Treg cell function.

Nuclear factor Foxp3 determines regulatory T (Treg) cell fate and function via mechanisms that remain unclear. Here, we investigate the nature of Foxp3-mediated gene regulation in suppressing autoimmunity and antitumor immune response. Contrasting with previous models, we find that Foxp3-chromatin binding is regulated by Treg activation states, tumor microenvironment, and antigen and cytokine stimulations. Proteomics studies uncover dynamic proteins within Foxp3 proximity upon TCR or IL-2 receptor signaling in vitro, reflecting intricate interactions among Foxp3, signal transducers, and chromatin. Pharmacological inhibition and genetic knockdown experiments indicate that NFAT and AP-1 protein Batf are required for enhanced Foxp3-chromatin binding in activated Treg cells and tumor-infiltrating Treg cells to modulate target gene expression. Furthermore, mutations at the Foxp3 DNA-binding domain destabilize the Foxp3-chromatin association. These representative settings delineate context-dependent Foxp3-chromatin interaction, suggesting that Foxp3 associates with chromatin by hijacking DNA-binding proteins resulting from Treg activation or differentiation, which is stabilized by direct Foxp3-DNA binding, to dynamically regulate Treg cell function according to immunological contexts.

Identification of pediatric activated T-cell hepatitis using clinical immune studies.

BACKGROUND AND AIMS: The majority of indeterminate pediatric acute liver failure (PALF) cases are secondary to immune dysregulation, labeled activated T-cell hepatitis (TCHep). We aimed to describe a cohort of children with acute severe hepatitis and PALF and define how clinical immune labs may help identify the TCHep group. METHODS: Retrospective review of children with acute hepatitis and PALF between March 2020 and August 2022. Patients were classified as known diagnosis, indeterminate hepatitis (IND-Hep), or TCHep (defined by liver biopsy with predominant CD8 T-cell inflammation or development of aplastic anemia). RESULTS: 124 patients were identified: 83 with known diagnoses, 16 with TCHep, and 25 with IND-Hep. Patients with TCHep had significantly increased median total bilirubin levels (7.5 mg/dL (IQR 6.8-8.9) vs 1.5 mg/dL (IQR 1.0-3.6), p < 0.0001), soluble interleukin-2 receptor levels (4512 IU/mL (IQR 4073-5771) vs 2997 IU/mL (IQR 1957-3237), p = 0.02), and percent of CD8+ T-cells expressing perforin (14.5 % (IQR 8.0-20.0) vs 1.0 % (IQR 0.8-1.0), p = 0.004) and granzyme (37.5 % (IQR 15.8-54.8) vs 4.0 % (IQR 2.5-5.5), p = 0.004) compared to IND-Hep patients. Clinical flow cytometry showed that TCHep patients had significantly increased percent CD8+ T cells (29.0 % (IQR 24.5-33.5) vs 23.6 % (IQR 19.8-25.8), p = 0.04) and HLA-DR+ (16.0 % (IQR 14.5-24.5) vs 2.7 (1.8-5.3), p < 0.001) compared to IND-Hep patients indicative of increase in CD8+ T cells that are activated. CONCLUSIONS: Peripheral blood clinical immune studies demonstrate increased markers of CD8 T-cell activation, proliferation, and cytotoxic function for TCHep patients. These readily available immune function labs can be used to help distinguish patients with TCHep from those with other causes. This provides a non-invasive tool for early detection of potential TCHep before progression to liver failure.

Immunohistochemical inflammation in histologically normal gallbladders containing gallstones.

BACKGROUND: The aim of this study was to establish features of inflammation in histologically normal gallbladders with gallstones and compare the expression of inflammatory markers in acutely and chronically inflamed gallbladders. METHODS: Immunohistochemistry was performed on formalin-fixed paraffin-embedded gallbladders for tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-2R, and substance p in three groups: Group I (n = 60) chronic cholecystitis, Group II (n = 57) acute cholecystitis and Group III (n = 45) histologically normal gallbladders with gallstones. Expression was quantified using the H-scoring system. RESULTS: Median, interquartile range expression of mucosal IL-2R in Groups I (2.65, 0.87-7.97) and II (12.30, 6.15-25.55) was significantly increased compared with group III (0.40, 0.10-1.35, p < 0.05). Submucosal IL-2R expression in Groups I (2.0, 1.12-4.95) and II (10.0, 5.95-14.30) was also significantly increased compared with Group III (0.50, 0.15-1.05, p < 0.05). There was no difference in the lymphoid cell IL-6 expression between Groups I (5.95, 1.60-18.15), II (6.10, 1.1-36.15) and III (8.30, 2.60-26.35, p > 0.05). Epithelial IL-6 expression of Group III (8.3, 2.6-26.3) was significantly increased compared with group I (0.5, 0-10.2, p < 0.05) as was epithelial TNF-α expression in Group III (85.0, 70.50-92.0) compared with Groups I (72.50, 45.25.0-85.50, p < 0.05) and II (61.0, 30.0-92.0, p < 0.05). Lymphoid cell Substance P expression in Groups I (1.90, 1.32-2.65) and II (5.62, 2.50-20.8) was significantly increased compared with Group III (1.0,1.0-1.30, p < 0.05). Epithelial cell expression of Substance P in Group III (121.7, 94.6-167.8) was significantly increased compared with Groups I (75.7, 50.6-105.3, p < 0.05) and II (78.9, 43.5-118.5, p < 0.05). CONCLUSION: Histologically normal gallbladders with gallstones exhibited features of inflammation on immunohistochemistry.

COX2-dependent suppression of anticancer immunity.

Prostaglandin E2 (PGE2) is well known to promote tumor progression by boosting cancer cell proliferation while inhibiting anticancer immunity. Recent data from Lacher et al. and Morotti et al. demonstrate that one of the mechanisms through which PGE2 suppresses tumor-targeting immune responses involves downregulation of interleukin 2 (IL2) receptors and consequent inhibition of mitochondrial metabolism in T cells.

[Primary central nervous system lymphoma presenting as a unilateral internal auditory canal lesion: a case report].

A 61-year-old man with right hearing loss and staggering for seven months was diagnosed with sudden deafness although previous evaluation with MRI indicated minor abnormal findings. During follow-up, he developed hypogeusia, right facial nerve palsy, pain in right mandible, right-sided temporal pain, and cerebellar ataxia. Cerebrospinal fluid examination at admission revealed reduced glucose concentration and elevated soluble interleukin-2 receptor (sIL-2R) level, whereas serum sIL-2R level was within the normal range. Brain MRI showed a swollen contrast-enhanced lesion extending from the right internal auditory canal to the middle cerebellar peduncle. Gallium-67 (67Ga) single-photon emission-computed tomography-computed tomography (SPECT-CT) revealed abnormal accumulation at the lesion site. Pathologic analysis of the tumor after resection led to the diagnosis of primary central nervous system lymphoma. In the present case, the MRI and 67Ga SPECT-CT characteristics were distinct from those of vestibular schwannoma. In addition, elevation of sIL-2R in the cerebrospinal fluid but not in serum was useful for differential diagnosis.

The Impact of Tumor Hypoxia Modulation on sIL-2R Levels in Newly Diagnosed Diffuse Large B Cell Lymphoma (DLBCL) Patients Undergoing Chemotherapy: A Randomized Clinical Trial.

OBJECTIVE: Tumor hypoxia induces the production of Hypoxia-Inducible Factor (HIF)-1 alpha, which interacts with NF-kB, leading to cancer proliferation and metastasis. This study investigated the effect of tumor hypoxia modulation using carbogen (95% O2 and 5% CO2) and nicotinamide on reducing soluble interleukin-2 receptor (sIL-2R) levels in newly diagnosed DLBCL patients with tissue overexpression of HIF-1α ≥10%. MATERIAL AND METHODS: A prospective randomized controlled clinical trial was conducted at Dr. Kariadi Hospital in Semarang, Indonesia, from 2021 to 2022. Newly diagnosed DLBCL patients with tissue HIF-1α ≥10% were randomized into an intervention group (nicotinamide 2,000 mg + carbogen 10 liters/min during R-CHOP) and a control group (R-CHOP alone) for one cycle. sIL-2R levels were measured in the blood before and after intervention. RESULTS: The intervention group showed a significant reduction in sIL-2R levels after chemotherapy (p=0.026), with 85% of samples exhibiting a decrease. In contrast, only 45% of samples in the control group demonstrated a decrease in sIL-2R levels (p=0.184). The median sIL-2R level decreased from 139.50 pg/mL to 70.50 pg/mL in the intervention group, while the control group exhibited an increase from 182.50 pg/mL to 250.00 pg/mL following one cycle of chemotherapy. CONCLUSION: Tumor hypoxia modulation led to a significant decrease in serum sIL-2R levels, potentially through improvements in the crosstalk between hypoxia and inflammation pathways.

Suspension culture promoted the expansion of NK-92 cells ex vivo by enhancing the expression of IL-2 receptor.

Vigorous ex vivo expansion of NK-92 cells is a pivotal step for clinical adoptive immunotherapy. Interleukin-2 (IL-2) is identified as a key cytokine for NK-92 cells, and it can stimulate cell proliferation after binding to the IL-2 receptor (IL-2R). In this work, the differences in IL-2 consumption and IL-2R expression were investigated between the two culture modes. The results showed that suspension culture favored ex vivo expansion of NK-92 cells compared with static culture. The specific consumption rate of IL-2 in suspension culture was significantly higher than that in static culture. It was further found that the mRNA levels of the two IL-2R subunits remained unchanged in suspension culture, but the proportion of NK-92 cells expressing IL-2Rß was increased, and the fluorescence intensity of IL-2Rß was remarkably enhanced. Meanwhile, the proportion of cells expressing IL-2R receptor complex also increased significantly. Correspondingly, the phosphorylation of STAT5, a pivotal protein in the downstream signaling pathway of IL-2, was up-regulated. Notably, the expression level and colocalization coefficient of related endosomes during IL-2/IL-2R complex endocytosis were markedly elevated, suggesting the enhancement of IL-2 endocytosis. Taken together, these results implied that more IL-2 was needed to support cell growth in suspension culture. Therefore, the culture process was optimized from the perspective of cytokine utilization to further improve the NK-92 cell's expansion ability and function. This study provides valuable insight into the efficient ex vivo expansion of NK-92 cells.

Interleukin-2 signaling in the regulation of T cell biology in autoimmunity and cancer.

Interleukin-2 (IL-2) is a critical cytokine for T cell peripheral tolerance and immunity. Here, we review how IL-2 interaction with the high-affinity IL-2 receptor (IL-2R) supports the development and homeostasis of regulatory T cells and contributes to the differentiation of helper, cytotoxic, and memory T cells. A critical element for each T cell population is the expression of CD25 (Il2rα), which heightens the receptor affinity for IL-2. Signaling through the high-affinity IL-2R also reinvigorates CD8+ exhausted T (Tex) cells in response to checkpoint blockade. We consider the molecular underpinnings reflecting how IL-2R signaling impacts these various T cell subsets and the implications for enhancing IL-2-dependent immunotherapy of autoimmunity, other inflammatory disorders, and cancer.

[Successful treatment with tucidinostat in a patient with relapsed adult T-cell leukemia/lymphoma following allogeneic hematopoietic stem cell transplantation].

Aggressive types of adult T-cell leukemia-lymphoma (ATL), namely, the acute type, lymphoma type, and chronic type with poor prognostic factors, have a poor prognosis. Although allogeneic hematopoietic stem cell transplantation (HSCT) may improve prognosis, relapse is common. In June 2021, tucidinostat was approved for relapsed or refractory ATL in Japan. We report a case of a 62-year-old man with relapsed ATL after allogeneic HSCT. In March 2017, he was diagnosed with ATL (acute type) and received two courses of mLSG-15 therapy. ATL cells reappeared in his peripheral blood, so he underwent allogeneic bone marrow transplantation in September 2017. In June 2021, his soluble interleukin-2 receptor (sIL-2R) level increased, and he began experiencing sensory abnormalities in his face and legs. In September, he developed respiratory failure and was diagnosed with relapse of ATL. He was again treated with mLSG-15. His sIL-2R normalized and the sensory abnormalities decreased, but sIL-2R rose again in February 2022. After tucidinostat treatment was initiated, sIL-2R normalized and the patient's general condition improved. Tucidinostat shows promise as an effective treatment for ATL that has relapsed after allogeneic HSCT.

Evaluation of gene-gene interaction between the interleukin (IL)-2 and IL-2RA gene polymorphisms in schizophrenia patients in the Turkish Population.

OBJECTIVES: To evaluate the genetic polymorphisms in IL-2 and IL-2RA genes in schizophrenia (SCZ) patients by comparing them with healthy controls. METHODS: A sample of 127 patients with SCZ and 100 healthy volunteers were included in the case-control study. These individuals were consecutively selected from the Malazgirt State Hospital Psychiatry Outpatient Clinic in Mus, Turkey, over the three months from October 2020 to December 2020. The Structured Clinical Interview for DSM-5 Disorders, Clinician Version (SCID-5-CV) was used to confirm the diagnosis according to the DSM-5 criteria. In addition, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine gene polymorphisms from DNA material. RESULTS: Our findings indicated significant differences in the IL-2 genotype and allele frequencies between SCZ patients and the healthy control group. Specifically, the frequency of the homozygous GG genotype was notably higher in SCZ patients compared to the control group. Conversely, when comparing the IL-2RA genotype and allele frequencies of SCZ patients with the control group, no statistically significant differences were observed between the 2 groups. When compared to individuals with other genotypes, interaction analysis indicated that carriers of the GG/AG (IL-2/IL-2RA) genotype demonstrated a significantly increased risk of SCZ. CONCLUSION: In light of the analyses, our study indicates that while the IL-2 genotype polymorphism may be considered a risk factor for developing SCZ, the IL-2RA variant was not associated with SCZ among Turkish patients.

The soluble IL-2 receptor α/CD25 as a modulator of IL-2 function.

The pleiotropic cytokine interleukin-2 (IL-2) is an integral regulator of healthy and pathological immune responses, with the most important role in regulating the homeostasis of regulatory T cells. IL-2 signalling involves three distinct receptors: The IL-2 receptor α (IL-2Rα/CD25), IL-2Rß, and IL-2Rγ/γc . While IL-2Rß and γc are essential for signal transduction, IL-2Rα regulates the affinity of the receptor complex towards IL-2. A soluble form of the IL-2Rα (sIL-2Rα) is present in the blood of healthy individuals and increased under various pathological conditions. Although it is known that the sIL-2Rα retains its ability to bind IL-2, it is not fully understood how this molecule affects IL-2 function and thus immune responses. Here, we summarize the current knowledge on the generation and function of the sIL-2Rα. We describe the molecular mechanisms leading to sIL-2Rα generation and discuss the different IL-2 modulating functions that have been attributed to the sIL-2Rα. Finally, we describe attempts to utilize the sIL-2Rα as a therapeutic tool.

Frequency of HLA-DR+CD38hi T cells identifies and quantifies T-cell activation in hemophagocytic lymphohistiocytosis, hyperinflammation, and immune regulatory disorders.

BACKGROUND: Quantifying T-cell activation is essential for the diagnosis and evaluation of treatment response in various hyperinflammatory and immune regulatory disorders, including hemophagocytic lymphohistiocytosis. Plasma soluble IL-2 receptor (sIL-2R) is a well-established biomarker for evaluating systemic T-cell activation. However, the limited availability of sIL-2R testing could result in delayed diagnosis. Furthermore, high sIL-2R levels may not always reflect T-cell activation. OBJECTIVES: To address these limitations, this study investigated whether cell surface markers of T-cell activation, HLA-DR, and CD38, as assessed by flow cytometry, could be used to quantify systemic T-cell activation in a variety of inflammatory disease states and examine its correlation with sIL-2R levels. METHODS: Results for sIL-2R, CXCL9, and ferritin assays were obtained from patient's medical records. Frequency of HLA-DR+CD38high(hi) T-cells was assessed in different T-cell subsets using flow cytometry. RESULTS: In this study's cohort, activation in total CD8+ T (r = 0.65; P < .0001) and CD4+ (r = 0.42; P < .0001) T-cell subsets significantly correlated with plasma sIL-2R levels. At the disease onset, the frequency of HLA-DR+CD38hi T cells in CD8+ T (r = 0.65, P < .0001) and CD4+ T (r = 0.77; P < .0001) effector memory (TEM) compartments correlated strongly with sIL-2R levels. Evaluation of T-cell activation markers in follow-up samples also revealed a positive correlation for both CD4+ TEM and CD8+ TEM activation with sIL-2R levels; thus, attesting its utility in initial diagnosis and in evaluating treatment response. The frequency of HLA-DR+CD38hi T-cells in the CD8+ TEM compartment also correlated with plasma CXCL9 (r = 0.42; P = .0120) and ferritin levels (r = 0.32; P = .0037). CONCLUSIONS: This study demonstrates that flow cytometry-based direct T-cell activation assessed by HLA-DR+CD38hi T cells accurately quantifies T-cell activation and strongly correlates with sIL-2R levels across a spectrum of hyperinflammatory and immune dysregulation disorders.

Performance of serum soluble interleukin-2 receptor as a diagnostic marker for lymphoma in patients with fever.

There have been few reports on the diagnostic performance of soluble interleukin-2 receptor (sIL-2R) for lymphoma. A cross-sectional study was conducted at a university hospital; all patients who were admitted to the Division of General Internal Medicine and underwent serum sIL-2R testing were included. Patients were divided into two groups based on the presence of fever (≥ 38.0 °C). Among 602 patients, 421 had fever and 76 were diagnosed with lymphoma (48 of the 76 were in the febrile group). In all patients, the area under the receiver operating characteristic curve (AUROC) of sIL-2R for the diagnosis of lymphoma was 0.81 [95% confidence interval (CI), 0.75-0.87]. The AUROC was significantly higher in the febrile group (0.88; 95% CI, 0.81-0.94) than in the afebrile group (0.75; 95% CI, 0.65-0.85). In the febrile group, the sensitivity and specificity were 81.2% and 82.3%, respectively, with an optimal cutoff value of 3,250 U/mL. In the afebrile group, they were 89.3% and 54.9%, respectively, with a cutoff value of 868 U/mL. Serum sIL-2R showed high performance as an adjunctive diagnostic marker for lymphoma, particularly among febrile patients. Different cutoff values should be used for patients with and without fever to maximize diagnostic performance.