Lymphocyte subsets in lung tissues of interstitial pneumonia associated with untreated polymyositis/dermatomyositis

Characteristics and prognostic implications of peripheral blood lymphocyte subsets in patients with anti-MDA5 antibody positive dermatomyositis-interstitial lung disease

OBJECTIVES

To examine the characteristics of blood lymphocyte subsets in dermatomyositis-interstitial lung disease (DM-ILD) inflicted patients with positive anti-melanoma differentiation-associated gene 5 (anti-MDA5), as well as its prognosis value in this set of patients.

METHODS

Data were retrospectively collected from 253 DM-ILD patients from three hospitals in China between January 2016 to January 2021. Patients were grouped into anti-MDA5 antibody positive group (MDA5+ DM-ILD) and anti-MDA5 antibody negative group (MDA5- DM-ILD) based on myositis-specific autoantibody test results. Demographic characteristics, lymphocyte subsets patterns and other clinical features were compared between the two groups. The association of lymphocyte subsets with 180-day mortality was investigated using survival analysis in MDA5+ DM-ILD.

RESULTS

Out of 253 eligible patients with DM-ILD, 59 patients were anti-MDA5+ and 194 were anti-MDA5-. Peripheral blood lymphocyte count, CD3+ count, percentage of CD3+, CD3+CD4+ count, and CD3+CD8+ count was lower in MDA5+ DM-ILD than in MDA5- DM-ILD- (all P < 0.001) as well as CD3-CD19+ count (P = 0.04). In MDA5+ DM-ILD, CD3+CD8+ count ≤ 49.22 cell/μL (HR = 3.81, 95%CI [1.20,12.14]) and CD3-CD19+ count ≤ 137.64 cell/μL (HR = 3.43, 95%CI [1.15,10.24]) were independent predictors of mortality. CD3+CD8+ count ≤ 31.38 cell/μL was associated with a higher mortality risk in all DM-ILD patients (HR = 8.6, 95%CI [2.12,31.44]) after adjusting for anti-MDA5 and other clinical characteristics.

CONCLUSION

Significant lymphocytes decrease was observed in MDA5+ DM-ILD patients. CD3+CD8+ cell count was associated with worse prognosis in both MDA5+ DM-ILD and all DM-ILD patients.

CD8+ T Cell Phenotype and Function in Childhood and Adult-Onset Connective Tissue Disease

CD8+ T cells are cytotoxic lymphocytes that destroy pathogen infected and malignant cells through release of cytolytic molecules and proinflammatory cytokines. Although the role of CD8+ T cells in connective tissue diseases (CTDs) has not been explored as thoroughly as that of other immune cells, research focusing on this key component of the immune system has recently gained momentum. Aberrations in cytotoxic cell function may have implications in triggering autoimmunity and may promote tissue damage leading to exacerbation of disease. In this comprehensive review of current literature, we examine the role of CD8+ T cells in systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, polymyositis, and dermatomyositis with specific focus on comparing what is known about CD8+ T cell peripheral blood phenotypes, CD8+ T cell function, and CD8+ T cell organ-specific profiles in adult and juvenile forms of these disorders. Although, the precise role of CD8+ T cells in the initiation of autoimmunity and disease progression remains to be elucidated, increasing evidence indicates that CD8+ T cells are emerging as an attractive target for therapy in CTDs.

Expression of Inflammatory Markers in the Muscles of Patients with Idiopathic Inflammatory Myopathy According to the Presence of Interstitial Lung Disease

Background: Several studies have identified factors associated with the development of interstitial lung disease (ILD) in patients with idiopathic inflammatory myopathies (IIMs). However, few have assessed the association between ILD and muscle biopsy findings, including inflammatory marker expressions analyzed using immunohistochemistry (IHC). Methods: Muscle biopsies from patients who were newly diagnosed with IIMs between 2000 and 2017 were reviewed. ILD was diagnosed based on chest computed tomography findings at the time of diagnosis of IIMs. IHC staining was performed for CD3, CD4, CD8, CD20, CD68, CD163, MX1, MHC class I, and HLA-DR. The factors associated with the presence of ILD were evaluated by logistic regression analysis. Results: Of the 129 patients with IIM, 49 (38%) had ILD. In the muscle biopsy findings, CD4 expression, MX1 expression on immune cells, and expression of MHC class I and HLA-DR on myofibers were more common in patients with ILD than those without. In the logistic regression analysis, the HLA-DR expression on myofibers was significantly associated with the risk of ILD (OR, 2.39; 95% CI, 1.24–4.90, p = 0.012) after adjusting for pathologic findings, clinical features, and autoantibodies. Conclusion: The expression of HLA-DR on myofibers was associated with the presence of ILD in patients with IIM.

CD4+CXCR4+ T cells as a novel prognostic biomarker in patients with idiopathic inflammatory myopathy-associated interstitial lung disease

BACKGROUD

There is an unmet need for the development of new biomarkers for idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD).

METHODS

Peripheral CD4+CXCR4+ T cells, stromal cell-derived factor-1 and Krebs von den Lungen-6 were measured in patients with IIM-ILD (n = 85) and controls. The relation to pulmonary functions, high-resolution CT scores, specific clinical phenotypes and survival was analysed. Cytokine-expression profiling of these CD4+CXCR4+ T cells and their co-culture with pulmonary fibroblasts were conducted.

RESULTS

The peripheral percentages of CD4+CXCR4+ T cells were significantly elevated in IIM-ILD patients, and correlated with high-resolution CT score (r = 0.7136, P < 0.0001) and pulmonary function impairments, such as percentage of forced volume vital capacity (r = -0.4734, P = 0.0005). They were associated with anti-melanoma differentiation-associated gene 5 autoantibodies and the amyopathic DM phenotype. In IIM-ILD, peripheral percentages of CD4+CXCR4+ T cells ⩾30% revealed a 6-month mortality as high as 47%. These CD4+CXCR4+ T cells express high levels of IL-21 and IL-6. In vitro blockade of IL-21 signalling by neutralization of IL-21 or Janus kinase inhibitor could abolished the fibroblast proliferation.

CONCLUSION

Overall, peripheral CD4+CXCR4+ T cells appear to be a potentially valuable novel biomarker associated with the severity and prognosis of IIM-ILD. They promote pulmonary fibroblast proliferation via IL-21, which may herald future targeted treatments for this severe disease.

Association between nonspecific interstitial pneumonia and presence of CD20+ B lymphocytes within pulmonary lymphoid follicles

Nonspecific interstitial pneumonia (NSIP) is characterised by interstitial infiltration of lymphocytes and varying amounts of interstitial fibrosis. B cells have been suggested to contribute to the pathogenesis of NSIP. However, the relationship between B-lymphocyte and the clinical outcomes of NSIP was unclear. In this study, 50 patients with histopathologically confirmed NSIP from Peking Union Medical College Hospital between April 2003 to December 2012 were retrospectively analyzed. Using immunohistochemical analyses, CD20+ B cells were counted in the lymphoid follicles, perivascular, interstitial, and peribronchiolar regions of lung tissure. The CD20+ lymphocytes were mainly present in the lymphoid follicles. The number of follicular CD20+ lymphocytes was higher in the fibrosing than cellular NSIP pattern [255.08 (132.92-449.71) vs. 121.33 (63.54-282.88)/0.1 mm², p = 0.017]. After 1 year of therapy, the follicular CD20+ lymphocytes were significantly higher in patients whose forced vital capacity (FVC) worsened as compared to those who improved (p = 0.014). Additionally, follicular CD20+ lymphocytes were negatively correlated with the post-treatment percentage change in FVC (rho = -0.397, p = 0.004). However, follicular CD20+ lymphocytes were not correlated with survival. These results suggested that pulmonary follicular CD20+ lymphocytes were correlated with the fibrosing pattern of NSIP and predicted less clinical improvement after treatment.

T-cell receptor-mediated characteristic signaling pathway of peripheral blood T cells in dermatomyositis and polymyositis

The characteristics of T cell expression in peripheral blood have been previously described in dermatomyositis (DM) and polymyositis (PM); however, their intracellular signaling profiles remain unknown. The purpose of this study was to investigate the T-cell receptor (TCR)-mediated intracellular signaling in peripheral blood T cells in DM and PM. Peripheral blood T cells from 86 patients with DM (n = 57) and PM (n = 29) were used for experimental investigations. T-cell subtypes and TCR-induced phosphorylated zeta-chain-associated protein kinase 70 (pZAP70) were analyzed by flow cytometry. Signal transducer and activator of transcription (STAT) and some inhibitory factors in T cells with TCR stimulation were also investigated by quantitative real-time polymerase chain reaction. T cell counts were significantly lower in DM than in PM. In addition, STAT, forkhead box transcription factor (FoxP3), and pZAP70 expression in CD4⁺ T cells was suppressed in DM, whereas STAT and pZAP70 expression in CD8⁺ T cells was induced in PM. Especially in DM, a positive correlation between CD4⁺ T cell counts and STAT expression was detected. In addition, low CD4⁺ T cell counts as well as reduced STAT expression were prominent in patients with interstitial lung disease. STAT and pZAP70 expression significantly improved after clinical remission in both DM and PM, although expression of FoxP3 remained suppressed. Besides, upregulation of suppressor of cytokine signaling-3 (SOCS3) and downregulation of interleukin 6 signal transducer (IL6ST) in CD4⁺ T cells were observed in both DM and PM; however, no significant improvements were detected after clinical remission. The results of the present study suggested that TCR-mediated signaling may be a key pathway to determine the different characteristics of peripheral blood T cells between DM and PM. In addition, upregulation of SOCS3 and downregulation of IL6ST and FoxP3 in CD4⁺ T cells may cause an imbalance in intracellular signaling, especially in DM, suggesting that further studies are required to identify how the impaired signaling contributes to the development of the disease.

Update on the pharmacological treatment of adult myositis

The management of patients with idiopathic inflammatory myopathy (IIM) remains a challenge given the systemic features beyond active myositis. That is, recognizing the inflammatory arthropathy, varying dermatomyositis rashes, and overt and occult features of interstitial lung disease in addition to myositis adds to the complexity of diagnosis and treatment of IIM. However, clinicians now have available many more immunosuppressive drugs as well as biologic agents for use in patients with myositis and other autoimmune diseases. Here, the use of these agents is reviewed and support based on available published literature is provided even though many studies have been small and results somewhat anecdotal. Glucocorticoids remain the initial treatment of choice in most instances and methotrexate and azathioprine are often used early in the treatment course. These agents are followed by other immunosuppressive drugs, for example mycophenolate mofetil, tacrolimus, cyclosporine and cyclophosphamide, some of which are used alone while combinations of these agents also provide an effective option. There is more rationale for the use of biologic agents such as rituximab from a mechanistic perspective and, given the incorporation of validated core set measures in assessing myositis patients, we can look forward to better designed clinical trials in the future.

Treatment of inflammatory myopathy: emerging therapies and therapeutic targets

Despite the lack of placebo-controlled trials, glucocorticoids are considered the mainstay of initial treatment for idiopathic inflammatory myopathy and myositis-associated interstitial lung disease. Glucocorticoid-sparing agents are often given concomitantly with other immunosuppressive agents, particularly in patients with moderate or severe disease. First-line conventional immunosuppressive drugs include either methotrexate or azathioprine, and when they fail, more aggressive therapy includes mycophenolate mofetil, tacrolimus or cyclosporine, intravenous immunoglobulin, rituximab, or cyclophosphamide, used alone or in various combinations. Further investigations are required to assess the role of more novel therapies in the treatment of myositis and myositis-associated interstitial lung disease.

Phenotypes of Peripheral Blood Lymphocytes and Cytokine Expression in Polymyositis and Dermatomyositis before Treatment and after Clinical Remission

Objective

To investigate peripheral blood lymphocyte subpopulations, particularly helper T (Th) cells and cytokine expression before and after treatment in polymyositis (PM) and dermatomyositis (DM).

Patients and Methods

Ten patients with PM and 15 with DM were enrolled in this study. As a control we used 11 age-matched healthy subjects. We analyzed peripheral blood lymphocytes using flow cytometry. Serum cytokines were determined by enzyme-linked immunosorbent assay.

Results

Th2/Th1 and Th2/Th17 ratios were significantly higher in both PM and DM than in controls and this Th2-predominancy is marked in DM associated with interstitial pneumonia. IL-1β, IL-6 and TGF-β were significantly higher in both PM and DM and IL-4 showed a significant increase in DM when compared to controls. There was no significant correlation between either any lymphocyte subpopulations or serum cytokines and clinical severity markers such as the manual muscle strength test, serum creatine kinase, and the total CT score. Th2/Th17 in both PM and DM, as well as Th2/Th1 in the latter, significantly decreased after clinical remission compared with before treatment.

Conclusions

Th2-predominancy as shown by the increase in Th2/Th1 and Th2/Th17 ratios may suggest active disease in PM/DM but does not reflect clinical severity.

Coadministration of cyclosporin a with prednisolone in acute interstitial pneumonia complicating polymyositis/dermatomyositis

Objective

To investigate clinical effectiveness of prednisolone (PSL) and cyclosporin A (CyA), particularly continuous intravenous administration of the latter, in patients with interstitial pneumonia (IP) associated with polymyositis/dermatomyositis (PM/DM).

Methods

We reviewed the clinical findings and therapeutic outcomes of patients with PM/DM who had received PSL and CyA (PSL + CyA, n = 21 for DM and 2 for PM) or the former alone (n = 12 for DM and 7 for PM). All patients receiving PSL + CyA had active IP.

Results

Fifteen of the 21 DM patients receiving PSL + CyA showed favorable therapeutic outcomes of IP (recovery group), while the remaining 6 died of respiratory failure (death group). Before treatment PaO₂ in room air and %VC were significantly lower, and the total CT score was significantly higher in the death group than in the recovery one. Continuous intravenous administration of CyA was performed in 6 patients for severe IP requiring oxygen therapy, and of these 2 showed complete recovery from it.

Conclusions

Coadministration of PSL and CyA, particularly continuous intravenous infusion of the latter, from the early phase of illness may be a potent therapeutic option for PM/DM patients with decreases in PaO₂ and %VC and/or a high total CT score suggestive of a poor prognosis.

Interstitial lung disease associated with the idiopathic inflammatory myopathies: what progress has been made in the past 35 years?

Interstitial lung disease is commonly associated with the autoimmune inflammatory myopathies dermatomyositis and polymyositis and accounts for significant morbidity and mortality in these conditions. In the 35 years since the association between inflammatory myopathy and interstitial lung disease was initially described, there has been progress in diagnosing and treating this dis-order. Nevertheless, there remains much about pathogenesis and therapeutics to be learned. This review examines the changes in the understanding of this complex condition, highlighting recent advances and areas deserving of further study.

[Successful treatment of interstitial pneumonia and pneumomediastinum associated with polymyositis during pregnancy with a combination of cyclophosphamide and tacrolimus: A case report]

A 30-year-old pregnant woman experienced mild dyspnea in April 2009. She complained of mild myalgia and was subsequently admitted to our hospital in June 2009 because of worsening dyspnea. Physical examination revealed fine crackles in the lower lung field, but no eruptions externally. Laboratory findings revealed elevated serum levels of myogenic enzymes (aldolase, 17.6 IU/l and myoglobin, 247.2 ng/ml) and positive titers for the anti-Jo-1 antibody and hypoxia (PaO(2), 79.4 Torr). The chest radiograph revealed a ground-glass opacity. The patient was diagnosed as interstitial pneumonia (IP) associated with polymyositis (PM) at 20 weeks of gestation. On July 9, we commenced the initial treatment-steroid pulse therapy with 60 mg/day of prednisolone and 3 mg/day of tacrolimus. We also induced abortion. The treatment of corticosteroids and tacrolimus was, however, ineffective even after increasing the tacrolimus dose to 6 mg/day. On July 30, she suddenly experienced chest pain along with severe dyspnea. Computed tomography revealed the presence of pneumomediastinum and deterioration of the IP. We added cyclophosphamide pulse therapy to the existing regimen ; this improved the disease course, reduced hypoxia, and improved radiographic findings. We believe that this is a rare case of IP with PM during pregnancy.

Interstitial Lung Disease in Idiopathic Inflammatory Myopathy

The lung is one of the most common extra-muscular targets in idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) is a prevalent and often devastating manifestation of IIM. IIM-associated ILD (IIM-ILD) contributes to nearly 80% of the mortality in IIM with a reported prevalence of 65% of newly diagnosed IIM cases. Although ILD frequently accompanies clinical and laboratory findings of myositis, overt signs of muscle disease may be absent in the setting of significant lung disease. Understanding the varied scope of presentation of these diseases is essential to providing optimal patient care. This review will provide an in depth examination of ILD in IIM both from a rheumatologic and pulmonary perspective and will discuss the scope of disease, presenting features, genetic associations, pathogenesis, diagnosis, radiographic and histopathologic findings, along with biomarker assessment and a rationale for therapeutic intervention.

Characterization and peripheral blood biomarker assessment of anti-Jo-1 antibody-positive interstitial lung disease

OBJECTIVE

Using a combination of clinical, radiographic, functional, and serum protein biomarker assessments, this study was aimed at defining the prevalence and clinical characteristics of interstitial lung disease (ILD) in a large cohort of patients with anti-Jo-1 antibodies.

METHODS

A review of clinical records, pulmonary function test results, and findings on imaging studies determined the existence of ILD in anti-Jo-1 antibody-positive individuals whose data were accumulated in the University of Pittsburgh Myositis Database from 1982 to 2007. Multiplex enzyme-linked immunosorbent assays (ELISAs) for serum inflammation markers, cytokines, chemokines, and matrix metalloproteinases in different patient subgroups were performed to assess the serum proteins associated with anti-Jo-1 antibody-positive ILD.

RESULTS

Among the 90 anti-Jo-1 antibody-positive individuals with sufficient clinical, radiographic, and/or pulmonary function data, 77 (86%) met the criteria for ILD. While computed tomography scans revealed a variety of patterns suggestive of underlying usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia, a review of the histopathologic abnormalities in a subset of patients undergoing open lung biopsy or transplantation or whose lung tissue was obtained at autopsy (n = 22) demonstrated a preponderance of UIP and diffuse alveolar damage. Analysis by multiplex ELISA yielded statistically significant associations between anti-Jo-1 antibody-positive ILD and elevated serum levels of C-reactive protein (CRP), CXCL9, and CXCL10, which distinguished this disease entity from idiopathic pulmonary fibrosis and anti-signal recognition particle antibody-positive myositis. Recursive partitioning further demonstrated that combinations of these and other serum protein biomarkers can distinguish these disease subgroups at high levels of sensitivity and specificity.

CONCLUSION

In this large cohort of anti-Jo-1 antibody-positive individuals, the incidence of ILD approached 90%. Multiplex ELISA demonstrated disease-specific associations between anti-Jo-1 antibody-positive ILD and serum levels of CRP as well as the interferon-gamma-inducible chemokines CXCL9 and CXCL10, highlighting the potential of this approach to define biologically active molecules contributing to the pathogenesis of myositis-associated ILD.

Polymyositis/dermatomyositis and interstitial lung disease: A new therapeutic approach with T-cell-specific immunosuppressants

Interstitial lung disease (ILD) is a common complication of polymyositis (PM) and dermatomyositis (DM), and accounts for a significant proportion of their morbidity and mortality because of the resistance to therapeutic agents including corticosteroids. Its pathogenic mechanism is not known, but several studies have provided findings implicating that T-cells, especially activated CD8+ cells, may play essential roles, and thus could be therapeutic targets in this disease. To test this hypothesis, we began clinical investigation of the efficacy of T-cell-specific immunosuppressants, cyclosporine (CsA) and FK506, in PM/DM patients with ILD. In our retrospective nationwide multi-center study compiling a total of 53 patients, a combination of CsA and corticosteroids resulted in favorable early and long-term outcome in the majority of patients except for DM patients with acute ILD. In this subset, those who received the combination as an initial therapy had better survival than those who initially received corticosteroids alone. FK506 has a similar mode of action but is up to 100-fold more potent than CsA in vitro, and has been used in more refractory ILD cases. We next reviewed 5 PM/DM patients with ILD who failed on various immunosuppressants including CsA and were subsequently treated with FK506 in our hospital, and found that 3 improved promptly, 1 gradually and steadily, and another case responded slowly after prednisolone dose was increased. None developed adverse effects. In summary, these T-cell targeted therapies have a potential to be the cornerstone of the treatment for ILD in PM/DM patients. The combination therapy with CsA and corticosteroids may be efficacious especially when used early. FK506 may be advantageous even in refractory cases to CsA. These findings indicate that further investigation is warranted. Currently, prospective investigation of FK506 is underway.

Immune mechanisms in the pathogenesis of idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs), comprising polymyositis, dermatomyositis, and inclusion-body myositis, are characterized by inflammatory cell infiltrates in skeletal muscle tissue, muscle weakness, and muscle fatigue. The cellular infiltrates often consist of T lymphocytes and macrophages but also, in some cases, B lymphocytes. Emerging data have led to improved phenotypic characterization of the inflammatory cells, including their effector molecules, in skeletal muscle, peripheral blood, and other organs that are frequently involved, such as skin and lungs. In this review we summarize the latest findings concerning the role of T lymphocytes, B lymphocytes, dendritic cells, and other antigen-presenting cells in the pathophysiology of IIMs.

Step-up versus primary intensive approach to the treatment of interstitial pneumonia associated with dermatomyositis/polymyositis: a retrospective study

Corticosteroids (CS) are the standard initial treatment for interstitial pneumonia (IP) associated with dermatomyositis (DM)/polymyositis (PM). However, many patients fail to respond and have significantly high mortality even if immunosuppressive drugs (ISDs) are subsequently added, while a more intensive initial approach using ISDs is suggested to improve their survival. We conducted a retrospective study to examine the association between initial therapeutic approaches and clinical outcomes of active IP in DM/PM patients. We reviewed medical records of 34 consecutive DM/PM patients who had active IP defined by the presence of pulmonary function abnormality or active symptoms, and compared clinical outcome between those patients to whom ISDs were added if CS alone did not result in a favorable response (a step-up approach) and those who were started on ISDs simultaneously with CS (a primary intensive approach). Clinical endpoints were death, pulmonary death, and progression or improvement of pulmonary function. The step-up approach was used in 20 patients, to 11 of whom ISDs were eventually added after a median of 2.0 weeks, while the primary intensive approach was used in 14 patients. The primary intensive approach group had significantly better survival than the step-up approach group (P = 0.030 by the log-rank test). These two groups did not differ significantly in demographic characteristics and baseline clinical and laboratory features. Intensive approach by starting ISDs simultaneously with CS in the initial treatment for active IP in DM/PM patients was associated with better survival, emphasizing the impact of initial treatment on their survival. Prospective clinical investigation of this approach is now needed, but the limited clinical utility of CS as an initial treatment might ethically challenge clinical-trial designing.

Characterization of lymphocyte populations in nonspecific interstitial pneumonia

Study objectives

Nonspecific interstitial pneumonia (NSIP) has been identified as a distinct entity with a more favorable prognosis and better response to immunosuppressive therapies than usual interstitial pneumonia (UIP). However the inflammatory profile of NSIP has not been characterized.

Design

Using immunohistochemistry techniques on open lung biopsy specimens, the infiltrate in NSIP was characterized in terms of T and B cells, and macrophages, and the T cell population further identified as either CD4 (helper) or CD8 (suppressor-cytotoxic) T cells. The extent of Th1 and Th2 cytokine producing cells was determined and compared to specimens from patients with UIP.

Results

In ten NSIP tissue samples 41.4 ± 4% of mononuclear cells expressed CD3, 24.7 ± 1.8% CD4, 19.1 ± 2% CD8, 27.4 ± 3.9% CD20, and 14.3 ± 1.6% had CD68 expression. Mononuclear cells expressed INFγ 21.9 ± 1.9% of the time and IL-4 in 3.0 ± 1%. In contrast, biopsies from eight patients with UIP demonstrated substantially less cellular staining for either cytokine (INFγ; 4.6 ± 1.7% and IL-4; 0.6 ± 0.3%). Significant populations of CD20 positive B-cells were also identified.

Conclusion

The lymphocytic infiltrate in NSIP is characterized by an elevated CD4/CD8 T-cell ratio, and is predominantly of Th1 type, with additional populations rich in B-cells. Such features are consistent with the favorable clinical course observed in patients with NSIP compared to UIP.

Non-specific interstitial pneumonia; as the first clinical presentation of various collagen vascular disorders

Recently, we have experienced significant numbers of patients diagnosed with non-specific interstitial pneumonia (NSIP) by open lung biopsy or video-assisted thoracoscopic surgery. The purpose of this work was to describe the clinical features of patients with collagen vascular disorders (CVD) presenting NSIP in the absence of systemic involvement. This study also involved a retrospective review of patients with CVD presenting clinical and pathological evidence of NSIP in the absence of systemic manifestations of CVD. We found seven patients (six from our experience and one from literature review) with histologically proven NSIP who later developed typical CVD more than 6 months after the first presentation of NSIP. In these cases, it was difficult to speculate the development of CVD at the point of first presentation. Therefore, association of CVD should be considered in patients with NSIP even in the absence of classical systemic involvement.

Interstitial lung disease in polymyositis and dermatomyositis

Interstitial lung disease occurs in approximately one-third of patients with polymyositis and dermatomyositis (PM/DM) and has an adverse effect on survival. It is commonly a component of early PM/DM and can precede the onset of muscle or skin disease. Its most common histopathology is nonspecific interstitial pneumonia. This is a more benign pattern, with respect to response to immunosuppression and also long-term survival, than the pattern of usual interstitial pneumonia seen in idiopathic pulmonary fibrosis. The clinical course of PM/DM lung disease is heterogeneous. Progressive and nonprogressive disease needs to be distinguished by clinical and physiologic monitoring to avoid over-treatment. Patients with ongoing functional deterioration mostly benefit from immunosuppression. The experience with corticosteroid monotherapy is discouraging but cyclophosphamide, given as daily oral or intravenous pulse therapy together with corticosteroids, was found to be beneficial in many patients. Other immunosuppressants may be of benefit as well, but the weight of the current evidence supports the use of cyclophosphamide first.

Idiopathic non-specific interstitial pneumonia: as an “autoimmune interstitial pneumonia”

Recently, we have experienced significant number of patients diagnosed with non-specific interstitial pneumonia (NSIP) by open lung biopsy or video-assisted thoracoscopic surgery. The purpose of this study is to compare clinical and pathological features of idiopathic NSIP and NSIP associated with underlying diseases (mainly autoimmune disorders). Forty-six patients with histologically proven NSIP were retrospectively collected. Twenty-four patients had underlying diseases (12 polymyositis/dermatomyositis, 5 systemic sclerosis, 2 rheumatoid arthritis, 2 Sjogren's syndrome, 1 ulcerative colitis, 1 primary biliary cirrhosis, and 1 multiple myeloma). Twenty-two of the 46 patients had no underlying diseases. It was very difficult to distinguish idiopathic NSIP and NSIP associated with underlying diseases, clinically and radiologically. Pathologically, Lymphocytic pneumonitis was demonstrated in both groups, and it was impossible to distinguish idiopathic NSIP and NSIP associated with underlying diseases. Since generalized symptoms were not observed in patients with idiopathic NSIP, and clinical and pathological features were identical to NSIP with several autoimmune disorders, we postulate new clinical entities of "autoimmune interstitial pneumonia" in cases without underlying diseases.

Pulmonary complications of inflammatory myopathy

Pulmonary manifestations contribute significantly to the morbidity and mortality of the idiopathic inflammatory myopathies, ranging from intrinsic lung disease to secondary complications that include aspiration pneumonia, opportunistic infection, congestive heart failure, and hypoventilation. Newer classification schemes for interstitial lung disease have permitted closer correlation between histologic subtype and clinical outcome, while diagnostic techniques such as bronchoalveolar lavage have begun to define the cellular elements responsible for immune-mediated pulmonary dysfunction. Investigators have identified several serum markers correlating with inflammatory disease activity in the lung that should enhance noninvasive monitoring of therapeutic responses to newer regimens involving agents such as cyclosporine and tacrolimus. Taken together, these advances have contributed to better understanding of the immunopathogenesis of myositis-associated interstitial lung disease that should ultimately translate into more effective treatment.