Novel surfactant C variant c.325-47_374del without response to hydroxychloroquine treatment.

Pathogenic variants of SP-C, which cause various lung diseases with varying ages of onset, are inherited in an autosomal dominant manner or appear de novo as new mutations. We present a case of fatal respiratory failure in a female infant. Genetic analysis confirmed an intragenic deletion encompassing exon 4 in the SFTPC gene, starting in the intron region before exon 4, extending into the exon 4 and portion, in a heterozygous state. This variant, c.325-47_374del, in the SFTPC gene has not yet been described in the literature. Despite an experimental therapy with hydroxychloroquine, the baby girl died on Day 162.

Defining criteria for disease activity states in juvenile dermatomyositis based on the Juvenile Dermatomyositis Activity Index.

OBJECTIVES: To develop and validate the cut-offs in the Juvenile DermatoMyositis Activity Index (JDMAI) to distinguish the states of inactive disease (ID), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in children with juvenile dermatomyositis (JDM). METHODS: For cut-off definition, data from 139 patients included in a randomised clinical trial were used. Among the six versions of the JDMAI, JDMA1 (score range 0-40) and JDMAI2 (score range 0-39) were selected. Optimal cut-offs were determined against external criteria by calculating different percentiles of score distribution and through receiver operating characteristic curve analysis. External criteria included the modified Pediatric Rheumatology International Trials Organization (PRINTO) criteria for clinically ID in JDM (for ID) and PRINTO levels of improvement in the clinical trial (for LDA and HDA). MDA cut-offs were set at the score interval between LDA and HDA cut-offs. Cut-off validation was conducted by assessing construct and discriminative ability in two cohorts including a total of 488 JDM patients. RESULTS: The calculated JDMAI1 cut-offs were ≤2.4 for ID, ≤6.6 for LDA, 6.7-11 for MDA and >11 for HDA. The calculated JDMAI2 cut-offs were ≤5.2 for ID, ≤8.5 for LDA, 8.6-11.3 for MDA and >11.3 for HDA. The cut-offs discriminated strongly among disease activity states defined subjectively by caring physicians and parents, parents' satisfaction or non-satisfaction with illness outcome, levels of pain, fatigue, physical functional impairment and physical well-being. CONCLUSIONS: Both JDMAI1 and JDMAI2 cut-offs revealed good metrologic properties in validation analyses and are, therefore, suited for application in clinical practice and research.

Definition and Validation of the American College of Rheumatology 2021 Juvenile Arthritis Disease Activity Score Cutoffs for Disease Activity States in Juvenile Idiopathic Arthritis.

OBJECTIVE: To develop and validate new Juvenile Arthritis Disease Activity Score 10 (JADAS10) and clinical JADAS10 (cJADAS10) cutoffs to separate the states of inactive disease (ID), minimal disease activity (MiDA), moderate disease activity (MoDA), and high disease activity (HDA) in children with oligoarthritis and with rheumatoid factor-negative polyarthritis, based on subjective disease assessment by the treating pediatric rheumatologist. METHODS: The cutoffs definition cohort was composed of 1,936 patients included in the multinational Epidemiology, Treatment and Outcome of Childhood Arthritis (EPOCA) study. Using the subjective physician rating as an external criterion, 4 methods were applied to identify the cutoffs: mapping, Youden index, 90% specificity, and maximum agreement. The validation cohort included 4,014 EPOCA patients, patients from 2 randomized trials, and 88 patients from the PharmaChild registry. Cutoff validation was conducted by assessing discriminative and predictive ability. RESULTS: The JADAS10 cutoffs were 1.4, 4, and 13, respectively, for oligoarthritis and 2.7, 6, and 17, respectively, for polyarthritis. The cJADAS10 cutoffs were 1.1, 4, and 12, respectively, for oligoarthritis and 2.5, 5, and 16, respectively, for polyarthritis. The cutoffs discriminated strongly among different levels of pain and morning stiffness, between patients who were and those who were not prescribed a new medication, and between different levels of improvement in clinical trials. Achievement of ID and MiDA according to the new JADAS cutoffs at least twice in the first year of disease predicted better outcome at 2 years. CONCLUSION: The 2021 JADAS and cJADAS cutoffs revealed good metrologic properties in both definition and validation samples, and are therefore suitable for use in clinical trials and routine practice.

High-dose saccharin supplementation does not induce gut microbiota changes or glucose intolerance in healthy humans and mice.

BACKGROUND: Non-caloric artificial sweeteners (NCAS) are widely used as a substitute for dietary sugars to control body weight or glycemia. Paradoxically, some interventional studies in humans and rodents have shown unfavorable changes in glucose homeostasis in response to NCAS consumption. The causative mechanisms are largely unknown, but adverse changes in gut microbiota have been proposed to mediate these effects. These findings have raised concerns about NCAS safety and called into question their broad use, but further physiological and dietary considerations must be first addressed before these results are generalized. We also reasoned that, since NCAS are bona fide ligands for sweet taste receptors (STRs) expressed in the intestine, some metabolic effects associated with NCAS use could be attributed to a common mechanism involving the host. RESULTS: We conducted a double-blind, placebo-controlled, parallel arm study exploring the effects of pure saccharin compound on gut microbiota and glucose tolerance in healthy men and women. Participants were randomized to placebo, saccharin, lactisole (STR inhibitor), or saccharin with lactisole administered in capsules twice daily to achieve the maximum acceptable daily intake for 2 weeks. In parallel, we performed a 10-week study administering pure saccharin at a high dose in the drinking water of chow-fed mice with genetic ablation of STRs (T1R2-KO) and wild-type (WT) littermate controls. In humans and mice, none of the interventions affected glucose or hormonal responses to an oral glucose tolerance test (OGTT) or glucose absorption in mice. Similarly, pure saccharin supplementation did not alter microbial diversity or composition at any taxonomic level in humans and mice alike. No treatment effects were also noted in readouts of microbial activity such as fecal metabolites or short-chain fatty acids (SCFA). However, compared to WT, T1R2-KO mice were protected from age-dependent increases in fecal SCFA and the development of glucose intolerance. CONCLUSIONS: Short-term saccharin consumption at maximum acceptable levels is not sufficient to alter gut microbiota or induce glucose intolerance in apparently healthy humans and mice. TRIAL REGISTRATION: Trial registration number NCT03032640 , registered on January 26, 2017. Video abstract.

Long-term outcomes in patients with polyarticular juvenile idiopathic arthritis receiving adalimumab with or without methotrexate.

OBJECTIVES: Long-term safety and efficacy of adalimumab among patients with juvenile idiopathic arthritis (JIA) was evaluated through 6 years of treatment. METHODS: Children aged 4-17 years with polyarticular JIA were enrolled in a phase III, randomised-withdrawal, double-blind, placebo-controlled trial consisting of a 16-week open-label lead-in period, 32-week randomised double-blind period and 360-week long-term extension. Patients were stratified by baseline methotrexate use. Adverse events (AEs) were monitored, and efficacy assessments included JIA American College of Rheumatology (JIA ACR) 30%, 50%, 70% or 90% responses and the proportions of patients achieving 27-joint Juvenile Arthritis Disease Activity Score (JADAS27) low disease activity (LDA, ≤3.8) and inactive disease (ID, ≤1). RESULTS: Of 171 patients enrolled, 62 (36%) completed the long-term extension. Twelve serious infections in 11 patients were reported through 592.8 patient-years of exposure. No cases of congestive heart failure-related AEs, demyelinating disease, lupus-like syndrome, malignancies, tuberculosis or deaths were reported. JIA ACR 30/50/70/90 responses and JADAS27 LDA were achieved in 66% to 96% of patients at week 104, and 63 (37%) patients achieved clinical remission (JADAS27 ID sustained for ≥6 continuous months) during the study. Attainment of JIA ACR 50 or higher and JADAS27 LDA or ID in the initial weeks were the best predictors of clinical remission. Mean JADAS27 decreased from baseline, 22.5 (n=170), to 2.5 (n=30) at week 312 (observed analysis). CONCLUSIONS: Through 6 years of exposure, adalimumab was well tolerated with significant clinical response (up to clinical remission) and a relatively low retention rate.

Juvenile Idiopathic Arthritis: Roma Children Seem to Run More Risk than Non-Roma.

Background: Ethnic information regarding juvenile idiopathic arthritis (JIA) exists for various populations across the world but is fully lacking for Roma. We assessed the occurrence and clinical characteristics of JIA in Roma vs. non-Roma children. Methods: We obtained data on all outpatients (n = 142) from a paediatric rheumatology centre (age 3 to 18 years) in the eastern part of Slovakia (Kosice region). We assessed patients' age, gender, disease type and related extra-articular conditions by ethnicity. We obtained population data from the 2011 census. Results: The share of Roma children was higher in the clinical JIA sample than in the overall population (24.6%, n = 35, Roma in the sample vs. 10.8%, n = 142, Roma in the population, p < 0.05). Moreover, Roma children had been diagnosed more frequently with extra-articular conditions but did not differ in other symptoms. Treatments also did not differ by ethnicity. Conclusion: Roma children had been diagnosed more with JIA than their non-Roma peers. This calls for further research on the causes of this increased disease burden in Roma children.

Opportunistic infections in immunosuppressed patients with juvenile idiopathic arthritis: analysis by the Pharmachild Safety Adjudication Committee.

BACKGROUND: To derive a list of opportunistic infections (OI) through the analysis of the juvenile idiopathic arthritis (JIA) patients in the Pharmachild registry by an independent Safety Adjudication Committee (SAC). METHODS: The SAC (3 pediatric rheumatologists and 2 pediatric infectious disease specialists) elaborated and approved by consensus a provisional list of OI for use in JIA. Through a 5 step-procedure, all the severe and serious infections, classified as per MedDRA dictionary and retrieved in the Pharmachild registry, were evaluated by the SAC by answering six questions and adjudicated with the agreement of 3/5 specialists. A final evidence-based list of OI resulted by matching the adjudicated infections with the provisional list of OI. RESULTS: A total of 772 infectious events in 572 eligible patients, of which 335 serious/severe/very severe non-OI and 437 OI (any intensity/severity), according to the provisional list, were retrieved. Six hundred eighty-two of 772 (88.3%) were adjudicated as infections, of them 603/682 (88.4%) as common and 119/682 (17.4%) as OI by the SAC. Matching these 119 opportunistic events with the provisional list, 106 were confirmed by the SAC as OI, and among them infections by herpes viruses were the most frequent (68%), followed by tuberculosis (27.4%). The remaining events were divided in the groups of non-OI and possible/patient and/or pathogen-related OI. CONCLUSIONS: We found a significant number of OI in JIA patients on immunosuppressive therapy. The proposed list of OI, created by consensus and validated in the Pharmachild cohort, could facilitate comparison among future pharmacovigilance studies. TRIAL REGISTRATION: Clinicaltrials.gov NCT01399281; ENCePP seal: awarded on 25 November 2011.

First report on Giardia duodenalis assemblage F in Slovakian children living in poor environmental conditions.

BACKGROUND: Giardiasis is one of the most common gastrointestinal infections of humans and animals attributable to complex of eight morphologically identical genetic assemblages, further divided into sub-assemblages. Disease is common for a wide range of hosts and genetic characterization is needed for better understanding of multifaceted epidemiology for this protozoan parasite. The aim of this study was to identify genetic heterogeneity in assemblages and sub-assemblages of Giardiaduodenalis circulating among the children population living in deprived socioeconomic conditions. METHODS: A total of 333 stool samples from children in eastern Slovakia were collected during the period of 2015-2016 and analysed by molecular methods. Molecular characterization of G. duodenalis was performed by sequence analysis of triose phosphate isomerase gene (tpi) and glutamate dehydrogenase gene (gdh). RESULTS: G. duodenalis DNA was detected in 21 samples (6.3%), out of which 14 isolates (66.7%) belonged to assemblage B, 4 isolates (19.0%) to sub-assemblage AII and 3 isolates (14.3%) corresponded to assemblage F. As regards the determination of sub-assemblages of assemblage B, 4 isolates were characterized as sub-assemblage BIII and 6 isolates as sub-assemblage BIV. CONCLUSION: This study is the first finding of cat specific assemblage F in man not only in Slovakia, but also in Europe. The absence of molecular data about G. duodenalis in companion animals in Slovakia establishes a strong need for further investigation for potential sources of giardiasis and understanding the epidemiology will help to improve the preventive strategies in eradication of infection in this population.

T1R2 receptor-mediated glucose sensing in the upper intestine potentiates glucose absorption through activation of local regulatory pathways.

OBJECTIVE: Beyond the taste buds, sweet taste receptors (STRs; T1R2/T1R3) are also expressed on enteroendocrine cells, where they regulate gut peptide secretion but their regulatory function within the intestine is largely unknown. METHODS: Using T1R2-knock out (KO) mice we evaluated the role of STRs in the regulation of glucose absorption in vivo and in intact intestinal preparations ex vivo. RESULTS: STR signaling enhances the rate of intestinal glucose absorption specifically in response to the ingestion of a glucose-rich meal. These effects were mediated specifically by the regulation of GLUT2 transporter trafficking to the apical membrane of enterocytes. GLUT2 translocation and glucose transport was dependent and specific to glucagon-like peptide 2 (GLP-2) secretion and subsequent intestinal neuronal activation. Finally, high-sucrose feeding in wild-type mice induced rapid downregulation of STRs in the gut, leading to reduced glucose absorption. CONCLUSIONS: Our studies demonstrate that STRs have evolved to modulate glucose absorption via the regulation of its transport and to prevent the development of exacerbated hyperglycemia due to the ingestion of high levels of sugars.

The Slovak version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR).

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Slovak language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the three Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability, and construct validity (convergent and discriminant validity). A total of 108 JIA patients (5.6% systemic, 38.9% oligoarticular, 30.5% RF-negative polyarthritis, 25% other categories) and 100 healthy children were enrolled in two centres. Notably, none of the enrolled JIA patients is affected with psoriatic arthritis. The JAMAR components discriminated healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the Slovak version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.

Cardiovascular Risk of Nonsteroidal Anti-Inflammatory Drugs: An Under-Recognized Public Health Issue.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are drugs with analgesic, anti-inflammatory, and antipyretic activity. Their effect is achieved by the reduction in synthesis of prostanoids. Inhibition of prostanoids is responsible for a substantial risk of adverse effects. The risk of side effects affecting the gastrointestinal tract and kidneys has long been known. The possibilities of blood pressure elevation and the development of congestive heart failure are also widely recognized. Increased incidence of acute myocardial infarction in clinical trials with rofecoxib drew attention to the potential cardiotoxicity of selective cyclooxygenase-2 inhibitors, and similarly, concerns have been raised regarding the cardiovascular safety of non-selective NSAIDs. The safety of NSAIDs with regards to cardiovascular events has been studied in recent years in a large number of retrospective and prospective clinical studies and meta-analyses. The results indicate that cardiotoxicity is a class effect, but the magnitude of the risk is widely variable between individual NSAID drugs. This article aims to summarize the available data on the risk of adverse cardiovascular events with NSAIDs, the clinical impact of these events and possible underlying mechanisms.

Chronopotentiometric sensing of specific interactions between lysozyme and the DNA aptamer.

Specific DNA-protein interactions are vital for cellular life maintenance processes, such as transcriptional regulation, chromosome maintenance, replication and DNA repair, and their monitoring gives valuable information on molecular-level organization of those processes. Here, we propose a new method of label-free electrochemical sensing of sequence specific binding between the lysozyme protein and a single stranded DNA aptamer specific for lysozyme (DNAapta) that exploits the constant current chronopotentiometric stripping (CPS) analysis at modified mercury electrodes. Specific lysozyme-DNAapta binding was distinguished from nonspecific lysozyme-DNA interactions at thioglycolic acid-modified mercury electrodes, but not at the dithiothreitol-modified or bare mercury electrodes. Stability of the surface-attached lysozyme-DNAapta layer depended on the stripping current (Istr) intensity, suggesting that the integrity of the layer critically depends on the time of its exposure to negative potentials. Stabilities of different lysozyme-DNA complexes at the negatively polarized electrode surface were tested, and it was shown that structural transitions of the specific lysozyme-DNAapta complexes occur in the Istr ranges different from those observed for assemblies of lysozyme with DNA sequences capable of only nonspecific lysozyme-DNA interactions. Thus, the CPS allows distinct discrimination between specific and non-specific protein-DNA binding and provides valuable information on stability of the nucleic acid-protein interactions at the polarized interfaces.

Electrochemical sensing of concanavalin A and ovalbumin interaction in solution.

In an attempt to develop a label- and reagent-free electrochemical method for the detection of lectin-glycoprotein interactions, we tested lectin-concanavalin A (ConA), glycoprotein-ovalbumin (Ova) and their complex using chronopotentiometric stripping (CPS) analysis and a hanging mercury drop electrode. Incubation of ConA with Ova resulted in an increase of the CPS peak H of the complex as compared to the CPS peaks of individual Ova and ConA proteins. Qualitatively similar results were obtained with other glycoprotein-lectin couples (ConA-RNase B and lectin from Sambucus nigra-fetuin). Using the CPS method, we were able to follow the course of complex formation in solution. Comparable responses of Ova, ConA and ConA-Ova complex were obtained not only at the mercury electrode but also with solid amalgam electrodes, which are more suitable for parallel analysis. It can be anticipated that electrochemical methods, namely CPS, will find application in glycomics and proteomics.

Interaction of singlet oxygen with bovine serum albumin and the role of the protein nano-compartmentalization.

Singlet molecular oxygen ((1)O2) contributes to protein damage triggering biophysical and biochemical changes that can be related with aging and oxidative stress. Serum albumins, such as bovine serum albumin (BSA), are abundant proteins in blood plasma with different biological functions. This paper presents a kinetic and spectroscopic study of the (1)O2-mediated oxidation of BSA using the tris(2,2'-bipyridine)ruthenium(II) cation [Ru(bpy)3](2+) as sensitizer. BSA quenches efficiently (1)O2 with a total (chemical+physical interaction) rate constant kt(BSA)=7.3(±0.4)×10(8)M(-1)s(-1), where the chemical pathway represented 37% of the interaction. This efficient quenching by BSA indicates the participation of several reactive residues. MALDI-TOF MS analysis of intact BSA confirmed that after oxidation by (1)O2, the mass protein increased the equivalent of 13 oxygen atoms. Time-resolved emission spectra analysis of BSA established that Trp residues were oxidized to N'-formylkynurenine, being the solvent-accessible W134 preferentially oxidized by (1)O2 as compared with the buried W213. MS confirmed oxidation of at least two Tyr residues to form dihydroxyphenylalanine, with a global reactivity towards (1)O2 six-times lower than for Trp residues. Despite the lack of MS evidences, kinetic and chemical analysis also suggested that residues other than Trp and Tyr, e.g. Met, must react with (1)O2. Modeling of the 3D-structure of BSA indicated that the oxidation pattern involves a random distribution of (1)O2 into BSA; allowing also the interaction of (1)O2 with buried residues by its diffusion from the bulk solvent through interconnected internal hydrophilic and hydrophobic grooves.

Prednisone versus prednisone plus ciclosporin versus prednisone plus methotrexate in new-onset juvenile dermatomyositis: a randomised trial.

BACKGROUND: Most data for treatment of dermatomyositis and juvenile dermatomyositis are from anecdotal, non-randomised case series. We aimed to compare, in a randomised trial, the efficacy and safety of prednisone alone with that of prednisone plus either methotrexate or ciclosporin in children with new-onset juvenile dermatomyositis. METHODS: We did a randomised trial at 54 centres in 22 countries. We enrolled patients aged 18 years or younger with new-onset juvenile dermatomyositis who had received no previous treatment and did not have cutaneous or gastrointestinal ulceration. We randomly allocated 139 patients via a computer-based system to prednisone alone or in combination with either ciclosporin or methotrexate. We did not mask patients or investigators to treatment assignments. Our primary outcomes were the proportion of patients achieving a juvenile dermatomyositis PRINTO 20 level of improvement (20% improvement in three of six core set variables at 6 months), time to clinical remission, and time to treatment failure. We compared the three treatment groups with the Kruskal-Wallis test and Friedman's test, and we analysed survival with Kaplan-Meier curves and the log-rank test. Analysis was by intention to treat. Here, we present results after at least 2 years of treatment (induction and maintenance phases). This trial is registered with ClinicalTrials.gov, number NCT00323960. FINDINGS: Between May 31, 2006, and Nov 12, 2010, 47 patients were randomly assigned prednisone alone, 46 were allocated prednisone plus ciclosporin, and 46 were randomised prednisone plus methotrexate. Median duration of follow-up was 35.5 months. At month 6, 24 (51%) of 47 patients assigned prednisone, 32 (70%) of 46 allocated prednisone plus ciclosporin, and 33 (72%) of 46 administered prednisone plus methotrexate achieved a juvenile dermatomyositis PRINTO 20 improvement (p=0.0228). Median time to clinical remission was 41.9 months in patients assigned prednisone plus methotrexate but was not observable in the other two treatment groups (2.45 fold [95% CI 1.2-5.0] increase with prednisone plus methotrexate; p=0.012). Median time to treatment failure was 16.7 months in patients allocated prednisone, 53.3 months in those assigned prednisone plus ciclosporin, but was not observable in patients randomised to prednisone plus methotrexate (1.95 fold [95% CI 1.20-3.15] increase with prednisone; p=0.009). Median time to prednisone discontinuation was 35.8 months with prednisone alone compared with 29.4-29.7 months in the combination groups (p=0.002). A significantly greater proportion of patients assigned prednisone plus ciclosporin had adverse events, affecting the skin and subcutaneous tissues, gastrointestinal system, and general disorders. Infections and infestations were significantly increased in patients assigned prednisone plus ciclosporin and prednisone plus methotrexate. No patients died during the study. INTERPRETATION: Combined treatment with prednisone and either ciclosporin or methotrexate was more effective than prednisone alone. The safety profile and steroid-sparing effect favoured the combination of prednisone plus methotrexate. FUNDING: Italian Agency of Drug Evaluation, Istituto Giannina Gaslini (Genoa, Italy), Myositis Association (USA).

Complexation of cytochrome c with calixarenes incorporated into the lipid vesicles and supported membranes.

We studied the interaction of cytochrome c (cyt c) with specific calixarenes (CX) incorporated into the large unilamellar vesicles (LUV) composed of dimyristoylphosphatidylcholine (DMPC) or supported lipid membranes (sBLM) and compared this with not specific adsorption of cyt c to the LUV containing DMPC and anionic phosphatidic acid (PA) or sBLM composed of a mixture of DMPC and dimyristoylphosphatidic acid (DMPA). We showed that with increasing concentration of CX the average size of LUV increased and zeta potential become more negative as it is suggested from dynamic light scattering experiments. For PA containing LUV the increase in vesicle diameter was less expressed, but zeta potential decreased similarly like that of LUV contained CX. Cyt c did not affect significantly the LUV size, but reduced the negative zeta potential both for CX and PA containing vesicles. Electrochemical impedance spectroscopy allowed us to determine binding of cyt c to sBLM contained CX or DMPA. In both cases we observed decrease of charge transfer resistance with increasing cyt c concentration. The analysis of binding process suggests that the main driving force for interaction of cyt c with sBLM is the negative surface charge.

Serum level of KL-6 as a marker of interstitial lung disease in patients with juvenile systemic sclerosis.

OBJECTIVE: Serum KL-6 has been found to be elevated in diseases characterized by diffuse interstitial lung involvement. The purpose of this study was to evaluate serum KL-6 as a marker of interstitial lung disease (ILD) in patients with juvenile systemic sclerosis (JSS). METHODS: Serum concentrations of KL-6 were measured with an immunoassay in 39 serum samples from 12 children with diffuse cutaneous form of JSS (6 patients with and 6 patients without ILD) and from 20 healthy controls comparable for age. In patients sampled serially, the relationship of KL-6 concentrations with the severity of ILD and its response to treatment were evaluated. RESULTS: Serum concentrations of KL-6 were significantly higher in patients with ILD (1687 +/- 979 IU/ml) than in patients without (345 +/- 95 IU/ml, p < 0.01) and healthy controls (311 +/- 114 IU/ml, p < 0.001). Serum KL-6 concentrations of patients without ILD were not statistically different from those of healthy controls. We found a significant correlation of serum KL-6 concentrations with vital capacity and with diffusing capacity for carbon monoxide (DLCO). Analysis of individual patients showed that serum concentrations of KL-6 were correlated with ILD severity and its response to treatment. CONCLUSION: Measurement of serum KL-6 concentration is a useful noninvasive marker of pulmonary fibrosis in children with JSS. Its advantages over conventional methods of ILD assessment, such as pulmonary function test and high-resolution computerized tomography, are that it is easy to quantify and to measure repeatedly and it does not need children's cooperation.