Germline HAVCR2/TIM-3 Checkpoint Inhibitor Receptor Deficiency in Recurrent Autoinflammatory Myocarditis.

Myocarditis can be caused by viral infection, drug reaction or general inflammatory condition. To provide understanding on inflammatory myocarditis, we describe clinical, genetic, and immunological properties of a young male patient who suffered from recurrent myocarditis episodes since the age of four years. Electrocardiography, troponin I/T, echocardiography, myocardial magnetic resonance imaging and histological findings were consistent with recurrent myocarditis episodes. Homozygous c.245 A > G p.Tyr82Cys pathogenic variant in Hepatitis A Virus Cellular Receptor 2 (HAVCR2) gene encoding T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) receptor was found. Peripheral blood mononuclear cells were collected when the patient was asymptomatic; CD4+ and CD8+ T lymphoblasts, CD56+ natural killer cells and CD14+ monocytes were negative for surface TIM-3 expression. In vitro, TLR4 mediated interleukin-1ß (IL-1ß) response was high after LPS/ATP stimulation. Clinical symptoms responded to IL-1 receptor antagonist anakinra. TIM-3 p.Tyr82Cys CD4+ and CD8+ T cell proliferation in vitro was unrestrained. Findings on IL-2, interferon gamma, regulatory T cells, signal transducer and activator of transcription (STAT) 1, 3 and 4 phosphorylation, and PD-1 and LAG-3 checkpoint inhibitor receptor analyses were comparable to controls. We conclude that TIM-3 deficiency due to homozygous HAVCR2 c.245 A > G p.Tyr82Cys pathogenic variant in the patient described here is associated with autoinflammatory symptoms limited to early onset recurrent febrile myocarditis. Excessive IL-1ß production and defective regulation of T cell proliferation may contribute to this clinical condition responsive to anakinra treatment.

Inflammation and Neutrophil Oxidative Burst in a Family with NFKB1 p.R157X LOF and Sterile Necrotizing Fasciitis.

Loss-of-function (LOF) mutations in NFKB1, coding for p105, may cause common variable immunodeficiency due to dysregulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κΒ) pathway. Monoallelic LOF variants of NFKB1 can predispose to uncontrolled inflammation including sterile necrotizing fasciitis or pyoderma gangrenosum. In this study, we explored the impact of a heterozygous NFKB1 c.C936T/p.R157X LOF variant on immunity in sterile fasciitis patients and their family members. The p50 or p105 protein levels were reduced in all variant carriers. Interleukin-1ß (IL-1ß) and interleukin-8 (IL-8) levels were elevated in vitro, potentially contributing to the very high neutrophil counts observed during fasciitis episodes. Phosphorylation of p65/RelA was reduced in p.R157X neutrophils suggesting defective activation of canonical NF-κB. Oxidative burst after NF-κB-independent phorbol 12-myristate 13-acetate (PMA) stimulation was similar in both p.R157X and control neutrophils. Comparable amounts of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex subunits were found in p.R157X and control neutrophils. However, a compromised oxidative burst was observed in p.R157X neutrophils following activation of NF-κB-dependent mechanisms following stimulation of toll-like receptor 2 (TLR2) and Dectin-1. Neutrophil extracellular trap formation was not affected by p.R157X. In summary, the NFKB1 c.C936T/p.R157X LOF variant has an impact on inflammation and neutrophil function and may play a role in the pathogenesis of sterile necrotizing fasciitis.

Recurrent febrile seizures and serum cytokines: a controlled follow-up study.

BACKGROUND: The role of cytokines in the pathogenesis of febrile seizures (FSs) is unclear, and information regarding cytokine production outside of FS episodes is scarce. METHODS: In our controlled follow-up study of patients with FSs, we compared the levels of 12 serum cytokines after the patients' first FSs, during febrile episodes without FSs, after recurrent FSs, during healthy periods after FSs, and between patients and controls. RESULTS: Two-hundred fifty-one patients with first FS participated in the study, of whom 17 (mean age 1.6 years, SD 0.7) with recurrent FSs completed the protocol as required by the sample size calculations. The mean IL-1RA level was higher after the first FSs (2580 pg/mL, SD 1516) than during febrile episodes without FSs (1336 pg/mL, SD 1364, P = 0.006) and healthy periods after FSs (474 pg/mL, SD 901, P = 0.001). IL-1RA levels were also higher during first (2580 pg/mL) and recurrent FSs (2666 pg/mL, SD 1747) in comparison with febrile controls (746 pg/mL, SD 551) (P < 0.001 and P = 0.001, respectively), but there was no difference in the IL-1RA between febrile episodes without FSs and febrile controls. CONCLUSIONS: Patients with FSs produce stronger inflammatory reactions during febrile episodes with FSs compared with febrile episodes without FSs and febrile controls. IMPACT: In patients with FSs, IL-1RA was higher following first FS than during febrile episodes without FSs and healthy periods after FSs. IL-1RA was higher in patients with FSs following first and recurrent FSs than in febrile controls. There was no significant difference in IL-1RA between febrile episodes of patients without FSs and febrile controls. Using IL-1RA as a surrogate marker of IL-1 axis activity, our results indicate that patients with FSs produced stronger inflammatory reactions during FS episodes but not during other febrile episodes or healthy periods after FSs. Cytokines may play a role in pathogenesis of FSs.

Loss of DIAPH1 causes SCBMS, combined immunodeficiency, and mitochondrial dysfunction.

BACKGROUND: Homozygous loss of DIAPH1 results in seizures, cortical blindness, and microcephaly syndrome (SCBMS). We studied 5 Finnish and 2 Omani patients with loss of DIAPH1 presenting with SCBMS, mitochondrial dysfunction, and immunodeficiency. OBJECTIVE: We sought to further characterize phenotypes and disease mechanisms associated with loss of DIAPH1. METHODS: Exome sequencing, genotyping and haplotype analysis, B- and T-cell phenotyping, in vitro lymphocyte stimulation assays, analyses of mitochondrial function, immunofluorescence staining for cytoskeletal proteins and mitochondria, and CRISPR-Cas9 DIAPH1 knockout in heathy donor PBMCs were used. RESULTS: Genetic analyses found all Finnish patients homozygous for a rare DIAPH1 splice-variant (NM_005219:c.684+1G>A) enriched in the Finnish population, and Omani patients homozygous for a previously described pathogenic DIAPH1 frameshift-variant (NM_005219:c.2769delT;p.F923fs). In addition to microcephaly, epilepsy, and cortical blindness characteristic to SCBMS, the patients presented with infection susceptibility due to defective lymphocyte maturation and 3 patients developed B-cell lymphoma. Patients' immunophenotype was characterized by poor lymphocyte activation and proliferation, defective B-cell maturation, and lack of naive T cells. CRISPR-Cas9 knockout of DIAPH1 in PBMCs from healthy donors replicated the T-cell activation defect. Patient-derived peripheral blood T cells exhibited impaired adhesion and inefficient microtubule-organizing center repositioning to the immunologic synapse. The clinical symptoms and laboratory tests also suggested mitochondrial dysfunction. Experiments with immortalized, patient-derived fibroblasts indicated that DIAPH1 affects the amount of complex IV of the mitochondrial respiratory chain. CONCLUSIONS: Our data demonstrate that individuals with SCBMS can have combined immune deficiency and implicate defective cytoskeletal organization and mitochondrial dysfunction in SCBMS pathogenesis.

A Family With A20 Haploinsufficiency Presenting With Novel Clinical Manifestations and Challenges for Treatment.

BACKGROUND: Tumor necrosis factor α-induced protein 3 gene (TNFAIP3, also called A20) haploinsufficiency (HA20) leads to autoinflammation and autoimmunity. We have recently shown that a p.(Lys91*) mutation in A20 disrupts nuclear factor κB signaling, impairs protein-protein interactions of A20, and leads to inflammasome activation. METHODS: We now describe the clinical presentations and drug responses in a family with HA20 p.(Lys91*) mutation, consistent with our previously reported diverse immunological and functional findings. RESULTS: We report for the first time that inflammasome-mediated autoinflammatory lung reaction caused by HA20 can be treated with interleukin 1 antagonist anakinra. We also describe severe anemia related to HA20 successfully treated with mycophenolate. In addition, HA20 p.(Lys91*) was found to associate with autoimmune thyroid disease, juvenile idiopathic arthritis, psoriasis, liver disease, and immunodeficiency presenting with specific antibody deficiency and genital papillomatosis. CONCLUSIONS: We conclude that HA20 may lead to combination of inflammation, immunodeficiency, and autoimmunity. The condition may present with variable and unpredictable symptoms with atypical treatment responses.

Heterozygous TLR3 Mutation in Patients with Hantavirus Encephalitis.

Puumala hantavirus (PUUV) hemorrhagic fever with renal syndrome (HFRS) is common in Northern Europe; this infection is usually self-limited and severe complications are uncommon. PUUV and other hantaviruses, however, can rarely cause encephalitis. The pathogenesis of these rare and severe events is unknown. In this study, we explored the possibility that genetic defects in innate anti-viral immunity, as analogous to Toll-like receptor 3 (TLR3) mutations seen in HSV-1 encephalitis, may explain PUUV encephalitis. We completed exome sequencing of seven adult patients with encephalitis or encephalomyelitis during acute PUUV infection. We found heterozygosity for the TLR3 p.L742F novel variant in two of the seven unrelated patients (29%, p = 0.0195). TLR3-deficient P2.1 fibrosarcoma cell line and SV40-immortalized fibroblasts (SV40-fibroblasts) from patient skin expressing mutant or wild-type TLR3 were tested functionally. The TLR3 p.L742F allele displayed low poly(I:C)-stimulated cytokine induction when expressed in P2.1 cells. SV40-fibroblasts from three healthy controls produced increasing levels of IFN-λ and IL-6 after 24 h of stimulation with increasing concentrations of poly(I:C), whereas the production of the cytokines was impaired in TLR3 L742F/WT patient SV40-fibroblasts. Heterozygous TLR3 mutation may underlie not only HSV-1 encephalitis but also PUUV hantavirus encephalitis. Such possibility should be further explored in encephalitis caused by these and other hantaviruses.

Damaging heterozygous mutations in NFKB1 lead to diverse immunologic phenotypes.

BACKGROUND: The nuclear factor κ light-chain enhancer of activated B cells (NF-κB) signaling pathway is a key regulator of immune responses. Accordingly, mutations in several NF-κB pathway genes cause immunodeficiency. OBJECTIVE: We sought to identify the cause of disease in 3 unrelated Finnish kindreds with variable symptoms of immunodeficiency and autoinflammation. METHODS: We applied genetic linkage analysis and next-generation sequencing and functional analyses of NFKB1 and its mutated alleles. RESULTS: In all affected subjects we detected novel heterozygous variants in NFKB1, encoding for p50/p105. Symptoms in variant carriers differed depending on the mutation. Patients harboring a p.I553M variant presented with antibody deficiency, infection susceptibility, and multiorgan autoimmunity. Patients with a p.H67R substitution had antibody deficiency and experienced autoinflammatory episodes, including aphthae, gastrointestinal disease, febrile attacks, and small-vessel vasculitis characteristic of Behçet disease. Patients with a p.R157X stop-gain experienced hyperinflammatory responses to surgery and showed enhanced inflammasome activation. In functional analyses the p.R157X variant caused proteasome-dependent degradation of both the truncated and wild-type proteins, leading to a dramatic loss of p50/p105. The p.H67R variant reduced nuclear entry of p50 and showed decreased transcriptional activity in luciferase reporter assays. The p.I553M mutation in turn showed no change in p50 function but exhibited reduced p105 phosphorylation and stability. Affinity purification mass spectrometry also demonstrated that both missense variants led to altered protein-protein interactions. CONCLUSION: Our findings broaden the scope of phenotypes caused by mutations in NFKB1 and suggest that a subset of autoinflammatory diseases, such as Behçet disease, can be caused by rare monogenic variants in genes of the NF-κB pathway.

Autoimmunity, hypogammaglobulinemia, lymphoproliferation, and mycobacterial disease in patients with activating mutations in STAT3.

The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of immunodysregulation polyendocrinopathy enteropathy X-linked-like syndrome. Here, we immunologically characterized 3 patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T, and p.K658N, respectively). The patients displayed multiorgan autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B-cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4(-)CD8(-)) T cells, and decreased natural killer, T helper 17, and regulatory T-cell numbers. Notably, the patient harboring the K392R mutation developed T-cell large granular lymphocytic leukemia at age 14 years. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.

Clinical Efficiency of Topical Calcipotriol/Betamethasone Treatment in Psoriasis Relies on Suppression of the Inflammatory TNFα - IL-23 - IL-17 Axis.

The effects of topical calcipotriol/betamethasone combination therapy and betamethasone monotherapy on inflammatory T-cell numbers and molecular markers were compared in patients with psoriasis. Combination therapy down-regulated the expression of tumour necrosis factor (TNF)-α, interleukin (IL)-23A, IL-17A, S100A7, CCL-20 and interferon (IFN)-γ in skin and TNF-α, IL-6, IL-23A, T-bet and IFN-γ in peripheral blood mononuclear cells (PBMCs). Betamethasone monotherapy had less effect. Expression of FoxP3 in both skin and PBMCs was down-regulated by calcipotriol/betamethasone, but not by betamethasone. Immunohistochemical analysis revealed that calcipotriol/betamethasone reduced the numbers of CD4+ and CD8+ T cells and Tregs in psoriatic lesions more than betamethasone. Flow cytometric analyses demonstrated that calcipotriol/betamethasone decreased the numbers of circulating CD8+ T cells, Tregs, skin-homing Th17 memory cells and Th22 memory cells, while betamethasone had little or no effect. Glucocorticoid receptors GRα and GRß were expressed in psoriatic skin. In conclusion, calcipotriol increases the immunosuppressive power of betamethasone by suppressing the inflammatory TNF-α - IL-23 - IL-17 axis.

Expression of Glucocorticoid Receptors GRα and GRß in Bullous Pemphigoid.

First-line treatments of bullous pemphigoid (BP) are topical and systemic glucocorticoids (GC). The actions of GC are mediated by glucocorticoid receptors (GR), which exist in several isoforms, of which GRα and GRß are the most important. In many inflammatory diseases, up-regulation of GRß is associated with GC insensitivity. The aims of this study were to determine the expression of GRα and GRß in patients with BP and to investigate the effect of prednisolone treatment on the expression of GR isoforms in BP. Quantitative real-time PCR (qPCR) analysis demonstrated that GR isoform mRNAs are expressed in peripheral blood mononuclear cells (PBMC) from patients with BP. Expression of GRα and GRß protein was confirmed by immunohistochemical staining of BP skin biopsies and by Western blot analysis and flow cytometric analysis of PBMCs. During prednisolone treatment, GRα and GRß expression varied markedly, but changes were not suitable as a clinical marker of GC sensitivity in patients with BP.

CD4⁺ T-cell proliferation responses to wheat polypeptide stimulation in children at different stages of type 1 diabetes autoimmunity.

AIMS: Our aim was to study whether immune responses to wheat-based proteins are related to the development of type 1 diabetes. METHODS: We analysed proliferative T-cell responses after in vitro gliadin, gluten, whole wheat, and tetanus toxoid stimulation with a carboxyfluorescein succinimidyl ester (CFSE) based T-cell proliferation assay in children at various phases of type 1 diabetes autoimmunity and in healthy autoantibody-negative control children. RESULTS: At an early stage of beta cell autoimmunity the strength and frequencies of positive proliferation responses to gliadin, gluten, and whole wheat did not differ between newly seroconverted children positive for one islet autoantibody and the controls. However, in prediabetic children with at least two islet autoantibodies and also in children with newly diagnosed type 1 diabetes positive T-cell responses to gliadin were significantly less frequent and the strength of gliadin responses was reduced when compared to the controls. No differences were seen in T-cell responses to wheat-based antigens when comparing children with long-lasting type 1 diabetes with healthy controls. CONCLUSIONS/INTERPRETATION: Decreased in vitro T-cell responses to wheat-based antigens were observed in children with multiple islet autoantibodies and in those with newly diagnosed type 1 diabetes, probably reflecting a generally aberrant immune response during the development of type 1 diabetes.

XMEN disease caused by the novel MAGT1 p.(Trp136*) mutation may present with neuropsychiatric symptoms.

BACKGROUND: X-linked MAGT1 deficiency with increased susceptibility to EBV-infection and N-linked glycosylation defect (XMEN) disease is caused by MAGT1 loss-of-function (LOF) mutations. The disease commonly presents with respiratory symptoms. Although the central nervous system can be affected, the spectrum of neuropsychiatric symptoms is not completely understood. CASES: We describe a XMEN disease family presenting with atypical neuropsychiatric symptoms. The index, a previously healthy male, developed schizophrenia. Several years later, a novel hemizygous LOF MAGT1 c.407G > A, p.(Trp136X) LOF mutation and XMEN disease diagnosis was confirmed in his brother due to the burden of respiratory infections. Family screening also found the index to suffer from XMEN disease; the XMEN disease was concluded to contribute to the development of schizophrenia. CONCLUSIONS: Our case description demonstrates that the spectrum of XMEN disease clinical presentations can be variable, and the condition may also present with severe neuropsychiatric consequences. While respiratory infections are common among schizophrenia patients, the possibility of inborn errors in immunity should be considered whenever an unexplained personal or family history infection susceptibility is encountered. We recommend evaluating complete family history to exclude unusual monogenic disorders associated or presenting with psychiatric manifestations.

Serum HMGB1 in febrile seizures.

The role of high-mobility group box 1 (HMGB1) in the pathogenesis of febrile seizures (FSs) is unclear. In our controlled follow-up study, we compared serum levels of HMGB1 (s-HMGB1) in the same individuals after the first FS, during febrile episodes without a FS, after recurrent FS, during healthy periods after FS, and between patients and controls. In all, 122 patients with FSs were included in the final analysis, including 18 with recurrent FSs with a complete follow-up protocol. We recruited 30 febrile children and 18 matched febrile children without seizures as controls. S-HMGB1 was lower in patients with recurrent FSs after the first FS than that in matched febrile control children (median 1.12 µg/L (0.14-2.95) vs 1.79 µg/L (0.33-47.90), P<0.04). We did not find any other differences in s-HMGB1 between the groups. S-HMGB1 did not differ in different types of FSs. We updated a meta-analysis of s-HMGB1 in patients with FSs and found that the differences were significant only in the studies conducted in East Asian populations. We conclude that S-HMGB1 does not seem to be a key factor in the pathogenesis of FSs but differences in HMGB1 concentrations could explain some of the ethnicity related susceptibility to FSs.

Osteoclastogenesis of human peripheral blood, bone marrow, and cord blood monocytes.

Osteoclasts are multinucleated bone resorbing cells that can be differentiated from human monocytes in vitro. There are few studies comparing osteoclastogenesis of different monocyte sources. We compared monocytes from human bone marrow (BM), peripheral blood (PB), and umbilical cord blood (CB) and their osteoclastogenic potential by culturing them with RANKL (20 and 80 ng/ml) and M-CSF (10 ng/ml) for 14 days. We also cultured cells without growth factors, as umbilical cord blood monocytes have been reported to be able to fuse spontaneously into osteoclasts. The data was analysed on d4, d8, d11, and d14. After culture with RANKL and M-CSF, all types of cell cultures developed TRACP -positive multinuclear cells that were able to form resorption pits on human bone slices. Only occasional multinuclear cells and small infrequent resorbed areas could be found in PB and CB-derived cultures without growth factors. BM-derived cells formed greater resorption areas than PB- and CB-derived monocytes. The greatest monocyte population in BM samples were intermediate (CD14++CD16+) and in PB and CB classical monocytes (76.3% and 54.4%, respectively). In conclusion, our data demonstrates that bone resorbing osteoclasts can be differentiated from BM, PB and CB. However, the osteoclast precursor origin can affect the osteoclast properties and function.

Dipeptidyl Peptidase 4 Inhibitor‒Associated Bullous Pemphigoid Is Characterized by an Altered Expression of Cytokines in the Skin.

Dipeptidyl peptidase 4 inhibitors (DPP4is), commonly used drugs for treatment of type 2 diabetes, increase the risk for bullous pemphigoid (BP). Currently, the mechanism leading to the loss of immunological tolerance of the cutaneous adhesion molecule BP180 as well as similarities and differences in disease progression between DPP4i-associated BP (DPP4i-BP) and DPP4i-independent regular BP are largely unknown. We analyzed the expression of 32 cytokines and two proteases by Luminex and ELISA assays in samples taken from lesional and nonlesional skin of patients with regular BP or DPP4i-BP and healthy controls. Cytokines mediating B-cell survival and targeting such as BAFF, CCL4, CXCL12, and IL-6 were expressed at a higher level in the lesional regular BP skin than the levels in the lesional DPP4i-BP skin. The DPP4i-BP samples had increased levels of eosinophilic cytokines CCL1, CCL17, CCL26, and IL-5, which correlated with the serum level of anti-BP180 NC16A IgG autoantibodies. The mRNA expression of BAFF, IL6, CCL1, CCL17, CCL26, and IL5 measured by qPCR correlated with the protein levels. Taken together, the cutaneous cytokine profiles were found to provide distinctive molecular fingerprints between regular BP and DPP4i-BP.

Single-cell characterization of anti-LAG-3 and anti-PD-1 combination treatment in patients with melanoma.

BackgroundRelatlimab plus nivolumab (anti-lymphocyte-activation gene 3 plus anti-programmed death 1 [anti-LAG-3+anti-PD-1]) has been approved by the FDA as a first-line therapy for stage III/IV melanoma, but its detailed effect on the immune system is unknown.MethodsWe evaluated blood samples from 40 immunotherapy-naive or prior immunotherapy-refractory patients with metastatic melanoma treated with anti-LAG-3+anti-PD-1 in a phase I trial using single-cell RNA and T cell receptor sequencing (scRNA+TCRαß-Seq) combined with other multiomics profiling.ResultsThe highest LAG3 expression was noted in NK cells, Tregs, and CD8+ T cells, and these cell populations underwent the most significant changes during the treatment. Adaptive NK cells were enriched in responders and underwent profound transcriptomic changes during the therapy, resulting in an active phenotype. LAG3+ Tregs expanded, but based on the transcriptome profile, became metabolically silent during the treatment. Last, higher baseline TCR clonality was observed in responding patients, and their expanding CD8+ T cell clones gained a more cytotoxic and NK-like phenotype.ConclusionAnti-LAG-3+anti-PD-1 therapy has profound effects on NK cells and Tregs in addition to CD8+ T cells.Trial registrationClinicalTrials.gov (NCT01968109)FundingCancer Foundation Finland, Sigrid Juselius Foundation, Signe and Ane Gyllenberg Foundation, Relander Foundation, State funding for university-level health research in Finland, a Helsinki Institute of Life Sciences Fellow grant, Academy of Finland (grant numbers 314442, 311081, 335432, and 335436), and an investigator-initiated research grant from BMS.

Myeloid-related protein 8/14 in plasma and serum in patients with new-onset juvenile idiopathic arthritis in real-world setting in a single center.

OBJECTIVE: The aim of this study was to analyze the usefulness of myeloid-related protein 8/14 (MRP8/14) in the prediction of disease course in a real-world setting for patients with new-onset juvenile idiopathic arthritis (JIA), to identify the relationship between MRP8/14 and disease activity using the physician's global assessment of disease activity (PGA), and determine whether the MRP8/14 levels measured in serum and plasma are equally useful. METHODS: In this prospective follow-up study, 87 new-onset non-systemic JIA patients were studied. Blood and synovial fluid samples were collected prior to any antirheumatic medication use. MRP8/14 was measured from serum (S-MRP8/14), plasma (P-MRP8/14), and synovial fluid samples using ELISA. RESULTS: The baseline MRP8/14 blood levels were significantly higher in patients using synthetic antirheumatic drugs than in patients with no systemic medications at 1 year after diagnosis in serum (mean 298 vs. 198 ng/ml, P < 0.001) and in plasma (mean 291 vs. 137 ng/ml, P = 0.001). MRP8/14 levels at the time of JIA diagnosis were higher in patients who started methotrexate during 1.5-year follow-up compared to those who achieved long-lasting inactive disease status without systemic medications (serum: mean 298 vs. 219 ng/ml, P = 0.006 and plasma: 296 vs. 141 ng/ml, P = 0.001). P-MRP8/14 was the most effective predictive variable for disease activity (by PGA) in linear multivariate regression model (combined to ESR, CRP, leukocytes, and neutrophils), whereas S-MRP8/14 was not significant. CONCLUSION: Blood MRP8/14 levels at baseline seem to predict disease course in new-onset JIA patients. P-MRP8/14 might be better than S-MRP8/14 when assessing disease activity at the time of JIA diagnosis.