Marker For Interstitial Lung Disease Research Articles

Initial Respiratory System Involvement in Juvenile Idiopathic Arthritis with Systemic Onset Is a Marker of Interstitial Lung Disease: The Results of Retrospective Cohort Study Analysis.

Background: Pulmonary involvement in systemic juvenile idiopathic arthritis (SJIA) is a rare but dangerous complication. The main risk factors are already known, such as macrophage activation syndrome, a refractory course of systemic juvenile arthritis, infusion reaction to interleukin 1 and/or interleukin 6 blockers, trisomy 21, and eosinophilia. However, information about respiratory system involvement (RSI) at the onset of SJIA is scarce. Our study aimed to evaluate the specific features of children with SJIA with RSI and their outcomes. Methods: In a single-center retrospective cohort study, we compared the information from the medical records of 200 children with SJIA according to ILAR criteria or SJIA-like disease (probable/possible SJIA) with and without signs of RSI (dyspnea, shortness of breath, pleurisy, acute respiratory distress syndrome, and interstitial lung disease (ILD)) at the disease onset and evaluated their outcomes (remission, development of chronic ILD, clubbing, and pulmonary arterial hypertension). Results: A quarter (25%) of the SJIA patients had signs of the RSI at onset and they more often had rash; hepato- and splenomegaly; heart (pericarditis, myocarditis), central nervous system, and kidney involvement; hemorrhagic syndrome; macrophage activation syndrome (MAS, 44.4% vs. 9.0%, p = 0.0000001); and, rarely, arthritis with fewer active joints, compared to patients without RSI. Five patients (10% from the group having RSI at the onset of SJIA and 2.5% from the whole SJIA cohort) developed fibrosing ILD. All of them had a severe relapsed/chronic course of MAS; 80% of them had a tocilizumab infusion reaction and further switched to canakinumab. Unfortunately, one patient with Down's syndrome had gone. Conclusion: Patients with any signs of RSI at the onset of the SJIA are required to be closely monitored due to the high risk of the following fibrosing ILD development. They required prompt control of MAS, monitoring eosinophilia, and routine checks of night oxygen saturation for the prevention/early detection of chronic ILD.

Forensic application of three interstitial pneumonia markers: search for new pneumonia markers in dead bodies.

In forensic cases, detailed identification of pneumonia is important. Our objective was to statistically determine the applicability of three interstitial lung disease (ILD) markers for forensic diagnosis using serum collected from dead bodies with various postmortem intervals (PMIs). We retrospectively analyzed the levels of postmortem serum Krebs von den Lungen-6 (KL-6) and pulmonary surfactant-associated proteins A and D (SP-A and SP-D) using 221 samples obtained during forensic autopsy at our facility from 2019 to 2023. We evaluated the diagnostic efficacy of ILD markers for various pneumonias against the pathological diagnosis, and examined the assessment of the severity of ILD. When comparing the ILD group with bacterial pneumonia (BP) versus the control group, there was a significant increase in KL-6 in the ILD group. When comparing the severe ILD (SILD) group with the mild ILD (MILD) group, there was a significant increase in KL-6 and SP-D in the SILD group. The optimal cutoff values for differentiating SILD were 607.0 U/mL for KL-6, 55.5ng/mL for SP-A, and 160.0ng/mL for SP-D, and the sensitivity/specificity (%) of KL-6, SP-A, and SP-D for SILD were 84.1/95.2, 55.6/85.7, and 66.7/74.6, respectively. This is the first study to examine KL-6 in postmortem serum in forensic medicine. By analyzing dead bodies with various PMIs, our results confirmed statistically that postmortem serum KL-6 specifically detects ILD, postmortem serum SP-A has high sensitivity to lung injury, and postmortem serum SP-D is potentially useful in assessing the severity of ILD.

Significance of serum Krebs von den Lungen-6 in systemic sclerosis

BackgroundSystemic sclerosis (SSc) is a well-known multi-system connective tissue disease, it has an unidentified aetiology that is characterised by abnormal immune system activation, vascular injury, which may progress to faulty neovascularization and inadequate vessel remodelling, and tissue scarring of the skin, lungs, and other internal viscera. Krebs von den Lungen-6 is a kind of transmembrane glycoprotein of type II alveolar epithelial cells and is specific for determining its damage. Regardless of the cause, serum Krebs von den Lungen-6 levels have been investigated in interstitial lung disease (ILD) of several etiologies and have been found to be a significant serum marker for ILD. The current research aims to look into the relationship between serum Krebs von den Lungen-6 levels and disease severity and clinical manifestations, specifically interstitial pulmonary fibrosis, in patients with SSc. In this study, 30 patients with systemic sclerosis and 30 control subjects—15 dermatomyositis patients and 15 healthy volunteers— were also incorporated to see if the change in serum Krebs von den Lungen-6 levels is specific for SSc as dermatomyositis is another connective tissue disorder with lung affection.ResultsA statistically significant difference (P < 0.001) in the median value of Krebs von den Lungen-6 when compared to the control groups was observed, which was 447.95 (145.68–817.98) in the SSc patients group, 158.80 (130.00–730.70) in the dermatomyositis group, and 48.10 (39.50–103.90) in the healthy control group. A significantly higher median value of Krebs von den Lungen-6 in ground glass, honeycombing, and nodular HRCT was established, with P-value (P < 0.001). There was a highly statistically significant discrepancy in the median Krebs von den Lungen-6 value between patients with ILD (717.7) and patients without ILD (145.7) with P-value (P < 0.001). A statistically significant positive correlation was found between Krebs von den Lungen-6 (U/ml) and Disease duration (years), Medsger severity scale, Digital ulceration, modified Rodnan skin score (MRSS), and P-value (P < 0.05).ConclusionKrebs von den Lungen-6 could be a scleroderma biomarker. It has been linked to the development and severity of interstitial lung disease in systemic sclerosis patients and may shed light on the pathophysiology of some fibrotic lung changes.

RETRACTED ARTICLE: Serum bilirubin levels in primary Sjögren’s syndrome: an association with interstitial lung disease

ObjectiveWe aimed to assess the association between serum bilirubin levels and interstitial lung disease (ILD) in patients with Primary Sjögren’s syndrome (pSS).Materials and methodsThe retrospectively analysis included 89 consecutive patients with pSS, we collected the clinical materials of pSS patients from the electronic medical records, and all pSS patients were divide into pSS with ILD group and pSS without ILD group.ResultsSerum bilirubin levels were significantly lower in pSS patients with ILD than those without ILD (p = 0.010). Serum bilirubin levels showed a significant negative correlation with erythrocyte sedimentation rate (ESR) (r = -0.321, p = 0.002) in patients with pSS. A multivariable logistic regression analysis confirmed that serum bilirubin presented an independent association with ILD in patients with pSS (OR = 0.841, 95%CI:0.728–0.972, p = 0.019).ConclusionSerum bilirubin is independently associated with ILD and therefore may be a promising marker of ILD in patients with pSS.

INTERSTITIAL LUNG DISEASE IN A TODDLER WITH ANTI-MDA5 JUVENILE DERMATOMYOSITIS THAT IMPROVED WITH AGGRESSIVE, EARLY TREATMENT WITH STEROIDS AND MULTIPLE IMMUNOSUPPRESSANTS

INTERSTITIAL LUNG DISEASE IN A TODDLER WITH ANTI-MDA5 JUVENILE DERMATOMYOSITIS THAT IMPROVED WITH AGGRESSIVE, EARLY TREATMENT WITH STEROIDS AND MULTIPLE IMMUNOSUPPRESSANTS

M166 Evaluation of serum KL-6 assay as a clinical diagnostic marker of interstitial lung disease in Korean patients

M166 Evaluation of serum KL-6 assay as a clinical diagnostic marker of interstitial lung disease in Korean patients

KL-6 in ANCA-Associated Vasculitis Patients with and without ILD: A Machine Learning Approach

Simple SummaryKrebs von den Lungen-6 (KL-6) is a mucin involved in several cellular processes, and its expression increases following injured or regenerating type II pneumocyte. KL-6 was suggested to identify patients affected by fibrotic interstitial lung diseases (ILD) associated with rheumatologic disorders. This is the first study that has assessed whether serum KL-6 can distinguish ANCA-associated vasculitis (AAV) patients with ILD from those without ILD, and whether this biomarker and its changes over time are correlated with disease activity, vasculitic damage, and response to treatment. Thirteen AAV patients were enrolled, four of them with ILD. Higher serum KL-6 was found in AAV-ILD patients in comparison with those without ILD. The best KL-6 cutoff values of 368 U/mL and 301 U/mL at baseline and during follow-up, respectively, were suggested to distinguish the two groups. A direct correlation was found between serum KL-6 and disease activity. Our multicenter study demonstrated KL-6 as a reliable, non-invasive, and easy-to-perform marker of ILD in AAV patients, being helpful for disease activity assessment. Changes in serum concentrations of KL-6 over time could be useful for monitoring AAV patients. Further study of KL-6 as a marker of response to therapy during long-term follow-up would also be worthwhile.Background: ANCA-associated vasculitis (AAV) are small vessel vasculitis distinguished between microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). The former may have interstitial lung disease (ILD) associated with high morbidity and mortality. Here, Krebs von den Lungen-6 (KL-6), a marker of fibrotic ILD, was assessed for distinguishing AAV patients with ILD from those without ILD, and whether its changes over time are correlated with disease activity. Materials and Methods: Thirteen AAV patients (eight females, mean age 61 ± 14.8 years) were enrolled: six MPA and six GPA. Serum samples were assayed for KL-6 concentrations (Fujirebio Europe, Belgium). To investigate potential binary classifiers for diagnosis of AAV-ILD, we constructed a regression decision tree model. Results: Higher serum KL-6 were in AAV-ILD compared with those without ILD (972.8 ± 398.5 vs 305.4 ± 93.9, p = 0.0040). Area under the receiver operating characteristics curve showed 100% of the diagnostic performance of KL-6 for identifying the ILD involvement (accuracy 91.7%) and the best cutoff value of 368 U/mL (sensitivity 100% and specificity 87.5%). The decision tree model showed a 33% improvement in class purity using a cut-off value of 513 U/mL to distinguish AAV patients with and without ILD. Stratifying AAV patients as MPA and GPA with and without ILD considering T0 and T1 KL-6, the model obtained an improvement of 40% for classifying GPA non-ILD with a T0 serum KL-6 cut-off value of 513 U/mL and a T1 KL-6 cut-off of 301 U/mL. A direct correlation was found between serum T0 KL-6 and T0 BVAS (r = 0.578, p = 0.044). Conclusion: Our multicenter study demonstrated KL-6 as a reliable, non-invasive, and easy-to-perform marker of ILD in AAV patients and its helpfulness for disease activity assessment. Changes in serum concentrations of KL-6 over time could be useful for monitoring AAV patients. Further study of KL-6 as a marker of response to therapy during long-term follow-up would also be worthwhile.

Nailfold Capillaroscopic Changes as a Marker of Interstitial Lung Disease in Systemic Sclerosis: A Cross-Sectional Study in a Tertiary Care Hospital in Eastern India.

Background:Systemic sclerosis (SSc) is an autoimmune connective tissue disorder causing microvascular abnormality leading to Raynaud's phenomenon, skin tightening, and nailfold capillary changes. The patient may have systemic involvement, among them interstitial lung disease (ILD) and pulmonary arterial hypertension are mainly associated with disease-related mortality.Aims:To find out an association between nailfold capillaroscopic changes with ILD severity.Materials and Methods:An institution based cross-sectional study was performed among the patients of SSc above 18 years. Detailed history was taken. Clinical examinations, nailfold capillaroscopy (NFC) with a dermatoscope and high-resolution computed tomography (HRCT) scan of thorax were done. Data were analyzed in MedCalc statistical software version 20.Results:Out of total 43 patients, 74.4% (n = 32) were female. Mean age was 35.05 ± 7.24 years and mean duration 4.28 ± 2.81 years. Diffuse SSc was found in 88.37% (n = 38). On NFC, early, active, and late patterns were found in 30.2% (n = 13), 25.6% (n = 11), and 44.2% (n = 19) cases, respectively. On HRCT, early, active, and late ILD were present in 18.6% (n = 8), 37.2% (n = 16), and 30.2% (n = 13) cases, respectively. ILD changes were absent in 14% (n = 6) though NFC changes were present in them. Respiratory symptoms were absent in 20.93% (n = 9) patients though all had features of early NFC and among them 9.3% (n = 4) showed early ILD changes on HRCT. Significant associations were found between NFC changes and ILD severity (P = 0.0003), NFC changes and respiratory symptoms (P < 0.0001) and between ILD changes and respiratory symptoms (P < 0.0001).Discussion:NFC, an inexpensive procedure, can be performed in all patients of SSc to detect development of early ILD even before appearance of respiratory symptoms to prevent further progression.

Serum KL-6 as predictive and prognostic marker of interstitial lung disease in childhood connective tissue diseases: a pilot study

This study was aimed to evaluate serum KL-6 levels to determine if this marker can be used for diagnosing and assessing severity of interstitial lung disease (ILD) in children with connective tissue disorders. In total, 40 patients [18 patients with juvenile systemic lupus erythematosus (JSLE), 10 patients with juvenile idiopathic arthritis (JIA), 8 patients with juvenile mixed connective tissue disease (JMCTD), 3 patients with juvenile systemic sclerosis (JSSc), and 1 patient with juvenile dermatomyositis (JDM)] and 20 healthy controls were included in this study. Age, sex, and duration of CTD and ILD (if any) were recorded. Blood samples from all the patients and controls were examined by ELISA. 20 of the 40 patients with CTD (50%) had ILD, 12 were mild and 8 were severe as assessed by spirometry. The median serum KL-6 level was 102.7 U/mL (76.1-180.8) in the CTD with severe ILD group, 72.2 U/mL (58.4- 100.5) in the CTD with mild ILD group, 56.7 U/mL (35.8-68.5) in the CTD without ILD group, and 52.3 U/mL (32.8-62.4) in the control group. KL-6 levels were significantly higher in the CTD with ILD (p<0.05), at a cutoff of 63.4 U/ml identified by ROC curve, serum KL-6 showed a sensitivity of 95.2% and specificity of 89.7%. KL-6 is a valuable biomarker for diagnostic purposes and to detect severity in ILD in childhood CTD.

PH-ILD: Identification, Evaluation, and Monitoring: A Diagnostic View From Both Sides

PH-ILD: Identification, Evaluation, and Monitoring: A Diagnostic View From Both Sides

Biomarkers for interstitial lung disease and acute-onset diffuse interstitial lung disease in rheumatoid arthritis.

Interstitial lung disease (ILD) is frequently a complication of rheumatoid arthritis (RA) as an extra-articular manifestation which has a poor prognosis. Acute-onset diffuse ILD (AoDILD) occasionally occurs in RA and includes acute exacerbation of ILD, drug-induced ILD, and Pneumocystis pneumonia. AoDILD also confers a poor prognosis in RA. Previously-established biomarkers for ILD include Krebs von den lungen-6 and surfactant protein-D originally defined in patients with idiopathic pulmonary fibrosis; the sensitivity of these markers for RA-associated ILD (RA-ILD) is low. Although many studies on ILD markers have been performed in idiopathic pulmonary fibrosis, only a few validation studies in RA-ILD or AoDILD have been reported. Biomarkers for RA-ILD and AoDILD are thus still required. Recently, genomic, cytokine, antibody, and metabolomic profiles of RA-ILD or AoDILD have been investigated with the aim of improving biomarkers. In this review, we summarize current preliminary data on these potential biomarkers for RA-ILD or AoDILD. The development of biomarkers on RA-ILD has only just begun. When validated, such candidate biomarkers will provide valuable information on pathogenesis, prognosis, and drug responses in RA-ILD in future.

Lung magnetic resonance imaging in systemic sclerosis: a new promising approach to evaluate pulmonary involvement and progression.

Interstitial lung disease (ILD) is frequent and highly disabling in systemic sclerosis (SSc). Magnetic resonance imaging (MRI) is not routinely used to evaluate the lung, due to poorer spatial resolution compared to high-resolution computed tomography (HRCT). We aimed to compare lung MRI signal with HRCT and evaluate the role of MRI in predicting ILD progression. Thirty SSc patients underwent lung MRI and HRCT. STIR and T1 mapping sequences were acquired before and after gadolinium injection. Patients were classified as normal (group 1 with normal HRCT and MRI), discordant (group 2 without ILD signs on HRCT but areas of hyperintensity on MRI), and abnormal (group 3 with ILD signs on HRCT and areas of hyperintensity on MRI). Patients were followed up for ILD progression. Mean STIR and T1 values were different between the three groups (p < 0.0001). STIR values correlated with HRCT score (R = 0.79, p < 0.0001), lung ultrasound B-lines (R = 0.73, p < 0.0001), and %DLco (R = - 0.63, p = 0.0001). Nine events were recorded during a follow-up of 25 ± 20months. Continuous STIR values were independently associated with events (HR 1.018; CI 1.005-1.031, p = 0.005). A STIR value >90ms discriminated patients at a higher risk of worsening pulmonary involvement (HR 8.80; CI 1.81-42.74; p < 0.007). Lung MRI can detect SSc-related ILD, with good correlations with other ILD markers. STIR values, independently of HRCT appearance, may predict worsening lung involvement. Lung MRI, although very preliminary, is a promising tool that in a near future could help selecting patients for an early treatment of SSc-related ILD and a more appropriate use of HRCT. Key points • Lung MRI has the potential to differentiate inflammation-predominant versus fibrosis-predominant lesions, but it is not currently used in routine clinical practice to assess SSc-related ILD. • Lung MRI STIR and T1 values are significantly different between patients with and without SSc-related ILD. STIR values, independently of HRCT appearance, are also able to predict worsening lung involvement over time. • These preliminary data suggest that, in a near future, MRI could support the choice for an early treatment of SSc-related ILD, as well as a more appropriate use of HRCT.

Interleukin (IL)-17F and IL-17E are related to fibrosis and vasculopathy in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease that causes fibrosis and vasculopathy of the skin and internal organs against a background of autoimmune abnormalities. In recent years, the importance of the interleukin (IL)-17 family for inflammatory diseases has received much attention, but autoimmune diseases have not yet been fully explored. As for SSc, there is also no unified perspective on the involvement of the IL-17 family in its development, and few studies have been conducted linking IL-17F and IL-17E particularly to the disease severity. In the present study, we examined the correlation between serum IL-17F and IL-17E levels and disease severity in SSc patients. Moreover, the expression of the receptors for these cytokines, IL-17RB and IL-17RC, in skin tissues obtained by skin biopsy was examined by immunohistochemistry. Both cytokines were significantly elevated in the sera of patients with diffuse cutaneous SSc patients compared with healthy controls. Serum IL-17F levels correlated with modified Rodnan total skin thickness score, a semiquantitative measure of skin sclerosis, percent predicted forced vital capacity, percent predicted carbon monoxide lung diffusion capacity and serum levels of Krebs von den Lungen-6 and surfactant protein-D, serological markers of interstitial lung disease. Serum IL-17E levels were significantly correlated with percent predicted forced vital capacity and serum Krebs von den Lungen-6 levels. Serum levels of IL-17F and IL-17E also correlated with the prevalence of digital ulcers, and serum IL-17F levels were associated with elevated right ventricle systolic pressure values. In addition, IL-17RC and IL-17RB expression was increased in the skin tissues of diffuse cutaneous SSc patients. These results suggested that IL-17F and IL-17E could be involved in fibrosis and vasculopathy in SSc through their respective receptors in the affected organ tissues.

Computer-aided identification of interstitial lung disease based on computed tomography.

Identification of interstitial lung disease (ILD) may be difficult in certain cases using pulmonary function tests (PFTs) or subjective radiological analysis. We evaluated the efficacy of quantitative computed tomography (CT) with 3-dimensional (3D) reconstruction for distinguishing ILD patients from healthy controls. We retrospectively collected chest CT images of 102 ILD patients and 102 healthy matched controls, and measured the following parameters: lung parenchymal volume, emphysema indices low attenuation area LAA910 volume, LAA950 volume, LAA910%, and LAA950%, and mean lung density (MLD) for whole lung, left lung, right lung, and each lobe, respectively. The Mann-Whitney U test was used to compare quantitative CT parameters between groups. Receiver operating characteristic (ROC) curves, Bayesian stepwise discriminant analysis, and deep neural network analysis were used to test the discriminative performance of quantitative CT parameters. Binary logistic regression was performed to identify ILD markers. Total lung volume was lower in ILD patients than controls, while emphysema and MLD values were higher (P < 0.001) except LAA910 volume in right middle lobe. LAA910 volume, LAA950 volume, LAA910%, LAA950%, and MLD accurately distinguished ILD patients from healthy controls (AUC >0.5, P < 0.05), and high MLD was a significant marker for ILD (OR = 1.047, P < 0.05). This quantitative CT analysis can effectively identify ILD patients, providing an alternative to subjective image analysis and PFTs.

Predicting factors for disappearance of anti-mutated citrullinated vimentin antibodies in sera of patients with rheumatoid arthritis

Objectives: We aimed to determine the predicting factors for disappearance of anti-mutated citrullinated vimentin antibody (anti-MCV Ab) in sera from rheumatoid arthritis (RA) patients.Methods: In 2013, 95 RA patients whose Disease Activity Score with erythrocyte sedimentation rate were moderate to severe (DAS28-ESR ≥3.2) at baseline were enrolled. Titers of anti-MCV Ab and anti-cyclic citrullinated peptide (anti-CCP) Ab for 2013 and 2014 were measured. The association of anti-MCV disappearance with disease activity, treatment, interstitial lung disease (ILD), and serum markers of ILD were retrospectively examined. Predicting factors of anti-MCV disappearance were determined by multivariable analysis.Results: While anti-CCP positivity rate did not change during the year, anti-MCV Ab changed from positive to negative in 18 patients (=19.0%). Continuous biological disease-modifying anti-rheumatic drug use, prednisolone dose (≥5.0 mg daily), and low KL-6 level (<191 U/mL) were determined as predicting factors of anti-MCV disappearance by multivariable analysis. In our cohort, anti-MCV Ab disappearance was not linked to clinical and radiological improvement.Conclusion: Different from anti-CCP Ab, anti-MCV Ab in sera from RA patients can disappear in a year. Some predicting factors for such negative seroconversion were found, whereas clinical significance of anti-MCV Ab disappearance was undetermined.

Associations between nailfold capillaroscopy findings and interstitial lung disease in patients with mixed connective tissue disease.

IntroductionMixed connective tissue disease (MCTD) is a chronic immune-mediated disorder defined by the combined presence of serum anti-RNP antibodies and distinct clinical features including progressive lung fibrosis. The aim of this study was to evaluate potential associations between lung fibrosis in MCTD and specific clinical and laboratory findings including results of nailfold capillaroscopy (NFC) examination.Material and methodsPatients with MCTD who were admitted to the Departments of Allergy and Immunology or Dermatology at the University Hospital of Krakow (Poland) in 2015–2018 were identified based on comprehensive individual record review. Diagnosis of MCTD required fulfilment of at least one of the four widely accepted sets of diagnostic criteria. Clinical and laboratory data were collected, and statistical analysis was performed to identify potential predictors of interstitial lung disease (ILD).ResultsThirty patients (90% females) aged 22–81 years met the study inclusion criteria. The mean duration of symptoms associated with MCTD was 7.3 months. Photosensitivity and Raynaud’s phenomenon were the most common clinical manifestations (90% and 70%, respectively). Hand oedema, sclerodactyly and the presence of giant capillaries in NFC correlated significantly with the risk of lung involvement. In multivariate analysis, the presence of enlarged loops in NFC (giant capillaries) was identified as an independent factor for ILD (R 2 = 0.82, p < 0.0000001).ConclusionsThe NFC examination should be considered in all patients with a diagnosis of MCTD. The presence of giant capillaries may be a promising marker for interstitial lung disease in these patients, especially among those with a short duration of disease (i.e. < 1 year).

KL-6 is a long-term disease-activity biomarker for interstitial lung disease associated with polymyositis/dermatomyositis, but is not a short-term disease-activity biomarker

Objectives: We aimed to evaluate the usefulness of serum KL-6 for interstitial lung disease (ILD) with polymyositis/dermatomyositis (PM/DM).Methods: All consecutive and previously untreated adult patients with PM/DM who were admitted to our hospital from 2010 to 2015 were included. The associations between serum KL-6 levels and clinical information were retrospectively analyzed.Results: Baseline serum KL-6 levels were significantly higher in patients with ILD than in those without (n = 41 and 15, respectively; p < .001). In the 14 patients whose ILD improved within 4 weeks post-treatment, their serum KL-6 levels did not significantly decrease at 2 weeks, 4 weeks, or 3 months post-treatment (p = 1.00, 1.00, and .83, respectively). Conversely, their serum KL-6 levels significantly decreased at 6, 9, and 12 months post-treatment (p = .01 in all comparisons). In the 12 patients whose ILD remained unchanged or deteriorated in 4 weeks post-treatment, only the difference between their serum KL-6 levels at 3 and 12 months was significant (p = .003).Conclusions: The present study validated the serum KL-6 as a diagnostic marker for ILD in PM/DM. However, serum KL-6 is not a short-term disease-activity biomarker for ILD with PM/DM, but it is a long-term disease-activity biomarker.

Pre-operative evaluation of circulating KL-6 levels as a biomarker for epithelial ovarian carcinoma and its correlation with tumor MUC1 expression.

Krebs von den Lungen-6 (KL-6), a mucinous sialylated sugar chain on human mucin-1 glycoprotein (MUC1), is a diagnostic marker for interstitial lung diseases. Furthermore, elevated serum KL-6 levels have been observed in certain malignant tumor types of epithelial origin. The expression of MUC1 has been observed in patients with epithelial ovarian cancer (EOC) and is considered a potential therapeutic target. In the present study, KL-6 serum levels were investigated in patients clinically suspected of having malignant ovarian tumors. A total of 219 patients were enrolled in the study, which analyzed their serum KL-6 levels in addition to tumor expression of MUC1 using immunohistochemistry. High serum KL-6 levels were predominantly observed in patients with EOC, and did not occur in patients with benign or borderline tumors. The level of serum KL-6 was highly correlated with tumor stage, grade and histological type, and demonstrated superior sensitivity for the detection of ovarian cancer compared with that of serum cancer antigen 125. High serum KL-6 was significantly associated with shorter progression-free survival. In addition, tumor MUC1 expression status was significantly correlated with serum KL-6 levels. These data suggest that serum KL-6 may be a useful, non-invasive biomarker surrogate for tumor MUC1 expression in future clinical trials of MUC1-targeted therapy.

Serum KL-6 and surfactant protein-D as monitoring and predictive markers of interstitial lung disease in patients with systemic sclerosis and mixed connective tissue disease.

Interstitial lung disease (ILD) is frequent complication of systemic sclerosis (SSc) and mixed connective tissue disease (MCTD). The disease is heterogeneous, and its outcome is unpredictable. Some patients have severe and progressive deterioration of ILD, which is the leading cause of mortality. We aimed to determine whether serum levels of Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) correlate with SSc/MCTD-associated ILD activity. We retrospectively analyzed the medical records of 40 patients with SSc/MCTD-associated ILD: 29 patients with SSc and 11 patients with MCTD. Measurement of serum KL-6 and SP-D levels, pulmonary function tests, and high-resolution computed tomography (HRCT) performed in parallel were reviewed. Serum KL-6 correlated positively with diffusing capacity of the lung for carbon monoxide (DLCO) (% predicted) and disease extent on HRCT, and the changes in serum levels of KL-6 were significantly related to the changes in forced vital capacity (FVC) in SSc/MCTD-associated ILD. On the other hand, multivariate logistic regression analyses with calculation of the area under the curve of the receiver-operating characteristic curve suggested that a higher serum level of SP-D was a significant predictor of FVC decline in SSc/MCTD-associated ILD. Our study suggests that serum KL-6 can be a useful monitoring tool of SSc/MCTD-associated ILD activity. In contrast, serum SP-D may be a significant predictor of potential FVC decline in the short term.

Circulating thymus and activation-regulated chemokine/CC chemokine ligand 17 is a strong candidate diagnostic marker for interstitial lung disease in patients with malignant tumors: a result from a pilot study.

IntroductionSerum Krebs von den Lungen-6 (KL-6) level is an established diagnostic marker of interstitial lung disease (ILD). However, it is also elevated in patients with non-small cell lung cancer (NSCLC). The significance of circulating thymus and activation-regulated chemokine (TARC)/CC chemokine ligand 17 (CCL17) in malignant diseases remains unknown.MethodsWe measured circulating TARC/CCL17 and KL-6 using enzyme-linked immunosorbent assay and electrochemiluminescence immunoassay, respectively, in 26 patients with malignant disease and six patients with benign lung disease (BLD). The cutoff levels were 500 U/mL for KL-6 and 450 pg/mL for TARC/CCL17. The significance of the markers was evaluated in relationship to the presence of ILD (n=10). The statistical significance was set at P<0.05.ResultsThe KL-6 positive ratio was significantly higher in the patients with NSCLC (n=17) than in those with BLD. There was a significant difference in the KL-6 positive ratio between the patients with NSCLC without ILD and those with BLD without ILD. However, there were no significant differences in the TARC/CCL17 positive ratio between the patients with NSCLC and BLD or between those with NSCLC without ILD and those with BLD without ILD. The TARC/CCL17 positive ratio was significantly higher in the patients with malignancy and ILD than in those without ILD. There was also a significant difference in the TARC/CCL17 positive ratio between the patients with NSCLC without ILD and those with ILD.ConclusionTARC/CCL17 may be useful for the diagnosis of ILD in patients with malignancies. Confirmation of the results is warranted through a large-scale study.