Pulmonary involvement in mixed connective tissue disease: comparison with other collagen vascular diseases using high resolution CT

Childhood mixed connective tissue disease at disease onset: Evidence from a systematic review

OBJECTIVE

Childhood Mixed Connective Tissue Disease (cMCTD) is the rarest pediatric connective tissue disease that includes features of systemic lupus erythematosus, polymyositis/dermatomyositis, juvenile idiopathic arthritis, and systemic sclerosis, identified by Sharp in 1972 and whose diagnosis remains challenging. This systematic review aims to identify clinical features at the onset of cMCTD and manifestations not currently included into the available diagnostic criteria.

METHODS

A systematic literature review was performed in accordance with PRISMA guidelines 2020 using bibliographic databases: MEDLINE via PubMed and EMBASE.

ELIGIBILITY CRITERIA

patients diagnosed with MCTD with onset before 18 years.

STUDIES INCLUDED

registries, retrospective and prospective cohort studies, case series and reports with analysis of data on signs and symptoms of presentation.

RESULTS

39 articles were included (215 subjects, 82.5% female), mean age of 141 months (± 41 months DS, range 2.5-204). The most used criteria for the diagnosis of MCTD were the Kasukawa criteria (54.5%). The clinical manifestations described at onset were Raynaud's phenomenon (69.7%), arthritis (60.9%), muscular involvement (53.5%), dermatological signs (39.5%), swollen fingers or hands (29.3%), arthralgias (25.6%), fever (22.3%), lung involvement (14.4%), sclerodactily (13.5%), lymphadenopathy (10.7%) serositis (10.2%), esophageal involvement (6.9%), nervous system involvement (6.9%), xeroftalmia (3.7%), xerostomia (3.7%), hepatosplenomegaly (2.8%), cardiac involvement (2.8%), hepatitis (2.3%), parotiditis (2.3%), Hashimoto's thyroiditis (0.9%), ocular involvement (0.9%).

CONCLUSIONS

The data from this systematic review suggest great heterogeneity of the clinical presentation of cMCTD for which there are no validated diagnostic criteria that may suggest a new diagnostic approach to allow earlier or more accurate diagnosis in the future.

The phenotype of mixed connective tissue disease patients having associated interstitial lung disease

OBJECTIVE

We aimed to compare two matched populations of patients with MTCD with and without associated ILD and to identify predictive factors for ILD progression and severity.

METHODS

This international multicenter retrospective study (14 tertiary hospitals), included MCTD patients who fulfilled at least one historical MCTD classification criteria. ILD was defined by the presence of typical chest high-resolution computed tomography (HRCT) abnormalities. Factors associated with ILD were assessed at baseline. Long-term progressive ILD was assessed in MCTD-ILD patients with multiple forced vital capacity (FVC) measurements.

RESULTS

300 patients with MCTD were included. Mean age at diagnosis was 39.7 ± 15.4 years and 191 (63.7%) were women. Mean follow-up was 7.8 ± 5.5 years. At baseline, we identified several factors associated with ILD presence: older age (p = 0.01), skin thickening (p = 0.03), upper gastro-intestinal (GI) symptoms (p<0.001), FVC <80% (p<0.0001), diffusing capacity for carbon monoxide <80% (p<0.0001), anti-topoisomerase antibodies (p = 0.01), SSA/Ro antibodies (p = 0.02), cryoglobulinemia (p = 0.04) and elevated C-reactive protein (p<0.001). Patients with MTCD-ILD were more likely to be treated with synthetic immunosuppressant agents (p<0.001) in particular mycophenolate mofetil (p = 0.03). Digital ulcers (DU) were identified as a risk factor for FVC decline >10%. During follow-up mortality was higher in the MTCD-ILD group (p<0.001).

CONCLUSION

In this large international cohort of patients with MTCD, we identified different factors associated with ILD. Our findings also provide evidence that MCTD-ILD patients have increased mortality and that DU are associated with progressive lung disease.

Role of autoantibodies in the diagnosis and prognosis of interstitial lung disease in autoimmune rheumatic disorders

Interstitial lung disease (ILD) has been recognized as a frequent manifestation associated with a substantial morbidity and mortality burden in patients with autoimmune rheumatic disorders. Serum autoantibodies are considered good biomarkers for identifying several subsets or specific phenotypes of ILD involvement in these patients. This review features the role of several autoantibodies as a diagnostic and prognostic biomarker linked to the presence ILD and specific ILD phenotypes in autoimmune rheumatic disorders. The case of the diverse antisynthetase antibodies in the antisynthease syndrome or the anti-melanoma differentiation-associated 5 protein (MDA5) antibodies as a marker of a severe condition such as rapidly progressive ILD in patients with clinically amyopathic dermatomyositis are some of the associations herein reported in the group of myositis spectrum disorders. Specific autoantibodies such as the well-known anti-topoisomerase I (anti-Scl70) or the anti-Th/To, anti-U11/U12 ribonucleoprotein, and anti-eukaryotic initiation factor 2B (eIF2B) antibodies seems to be specifically linked to ILD in patients with systemic sclerosis. Overlap syndromes between systemic sclerosis and myositis, also have good ILD biomarkers, which are the anti-PM/Scl and anti-Ku autoantibodies. Lastly, other not so often reported disorders as being associated with ILD but recently most recognized as is the case of rheumatoid arthritis associated ILD or entities herein included in the miscellaneous disorders section, which include anti-neutrophil cytoplasmic antibody-associated interstitial lung disease, Sjögren's syndrome or the mixed connective tissue disease, are also discussed.

Pulmonary Manifestations of Systemic Sclerosis and Mixed Connective Tissue Disease

Systemic sclerosis (SSc) is a rare disease characterized by widespread collagen deposition resulting in fibrosis. Although skin involvement is the most common manifestation and also the one that determines the classification of disease, mortality in SSc is usually a result of respiratory compromise in the form of interstitial lung disease (ILD) or pulmonary hypertension (PH). Clinically significant ILD is seen in up to 40% of patients and PH in up to 20%. Treatment with either cyclophosphamide or mycophenolate has been shown to delay disease progression, whereas rituximab and lung transplantation are reserved for refractory cases.

Radiological images of interstitial pneumonia in mixed connective tissue disease compared with scleroderma and polymyositis/dermatomyositis

OBJECTIVE

Little has been reported on the radiological and pathological findings of interstitial pneumonia in mixed connective tissue disease (MCTD). There may be possible difference in treatment response and prognosis between the imaging patterns of systemic sclerosis (SSc)-like and polymyositis/dermatomyositis (PM/DM)-like. The purpose of this study was to examine whether the radiological images of interstitial pneumonia in MCTD presented SSc-like or PM/DM-like pattern, and to assess whether the imaging patterns corresponded to clinical and pathological features.

MATERIALS AND METHODS

This retrospective study included 29 patients with interstitial pneumonia who underwent surgical lung biopsy; 10 with SSc, 10 with PM/DM, and 9 with MCTD. High resolution computed tomography (HRCT) images were classified as SSc, PM/DM, or the other pattern by two radiologists independently without clinical information. The pathology of the lung specimens from MCTD patients were evaluated and compared with the imaging pattern.

RESULTS

The concordance rate between clinical diagnosis and radiological pattern was 100% in SSc patients, and 80% in PM/DM patients. Among patients with MCTD, imaging patterns were classified as SSc pattern in 4 (MCTD-SSc), PM/DM pattern in 4 (MCTD-PM/DM) and other in one. The imaging patterns did not always correlate with the clinical findings in MCTD patients. Pathologically, plasma cell infiltration and organizing pneumonia were relatively more frequent in MCTD-PM/DM, and smooth muscle hyperplasia was relatively more frequent in MCTD-SSc.

CONCLUSION

HRCT images in MCTD patients can be classified as SSc pattern or PM/DM pattern. MCTD-SSc and MCTD-PM/DM were corresponded to similar pathological findings of SSc and PM/DM.

Imaging of pulmonary involvement in rheumatic disease

Lung disease commonly occurs in connective tissue diseases (CTD) and is an important cause of morbidity and mortality. Imaging is central to the evaluation of CTD-associated pulmonary complications. In this article, a general discussion of radiologic considerations is followed by a description of the pulmonary appearances in individual CTDs, and the imaging appearances of acute and nonacute pulmonary complications. The contribution of imaging to monitoring disease, evaluating treatment response, and prognostication is reviewed. Finally, we address the role of imaging in the challenging multidisciplinary evaluation of interstitial lung disease where there is an underlying suspicion of an undiagnosed CTD.

Associations between anti-Ro52 antibodies and lung fibrosis in mixed connective tissue disease

OBJECTIVE

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 the study was to evaluate the potential impact of anti-SSA (i.e. Ro52 and Ro60) and anti-SSB autoantibodies as markers for disease outcomes in MCTD.

METHODS

Stored serum samples from 113 patients included in the cross-sectional, nationwide Norwegian MCTD cohort were screened for the presence of anti-Ro52, anti-Ro60 and anti-SSB by a commercial line immunoassay. Correlation analyses were carried out with clinical parameters, including quantitative lung fibrosis scores by high-resolution CT. Lung fibrosis was defined by reticular pattern changes according to the Fleischner Society CT criteria for interstitial lung disease.

RESULTS

Anti-Ro52 antibodies were present in 29%, anti-Ro60 in 19% and anti-SSB in 6% of the MCTD sera. High-resolution CT scoring identified lung fibrosis in 38 of 113 (34%) MCTD patients. Anti-Ro52 antibodies were detected in 50% (19 of 38) of the MCTD patients with lung fibrosis and in 19% (14 of 75) without lung fibrosis (P < 0.001). The odds ratio for the presence of anti-Ro52 antibodies in lung fibrosis was 4.4 (95% CI 1.8, 10.3). Anti-Ro52 antibodies were equally frequent in patients with mild to moderate (eight of 17; 44%) and severe fibrosis (11 of 21; 52%). Anti-Ro52 was not associated with any of the other clinical parameters assessed, nor was anti-Ro60 or anti-SSB.

CONCLUSION

Our cross-sectional data suggest that anti-Ro52 antibodies may serve as a potential marker for lung fibrosis in MCTD.

Connective Tissue Disease-Associated Interstitial Lung Disease

The connective tissue diseases (CTDs) are a group of systemic disorders characterized by autoimmunity and autoimmune-mediated organ damage. The lung is a frequent target and all components of the respiratory system are at risk. Interstitial lung disease (ILD) represents a broad group of diffuse parenchymal lung injury patterns characterized by varying degrees of inflammation and fibrosis, is a common manifestation of CTD particularly common in systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis, and is a leading cause of significant morbidity and mortality. The lung injury patterns of CTD-associated ILD (CTD-ILD) mirror those of idiopathic interstitial pneumonia and may arise at any time during the course of the CTD or may be the first manifestation of CTD. Patients with CTD that present with respiratory failure often present significant diagnostic dilemmas. Thorough and comprehensive assessments to exclude respiratory *infection, acute interstitial pneumonia, medication toxicity, pulmonary embolism, cardiac dysfunction, and diffuse alveolar hemorrhage are the fundamental components for the evaluation of such patients. Furthermore, patients with CTD are also at risk of acute exacerbations of underlying ILD. Acute exacerbations are manifested by subacute respiratory deterioration with worsening hypoxemia in the setting of new radiographic abnormalities. The prognosis of patients with CTD having respiratory failure is often quite poor, highlighting the need for prompt and thorough clinical assessments to determine the underlying etiology and implementation of appropriate therapeutic strategies.

Connective tissue disease-associated interstitial pneumonia and idiopathic interstitial pneumonia: similarity and difference

Interstitial lung diseases (ILDs) are increasingly recognized in patients with systemic diseases. Patients with early ILD changes may be asymptomatic. Features of ILD overlap among systemic diseases and with idiopathic variety. High-resolution computed tomography plays a central role in diagnosing ILDs. Imaging features are often nonspecific. Therapy- and complication-related lung changes would pose difficulty in diagnosing and classifying an ILD. Biology and prognosis of secondary ILDs may differ between different disease-related ILDs and idiopathic variety. Combination of clinical features, serological tests, pulmonary and extrapulmonary imaging findings, and pathology findings may help to diagnose ILDs.

Pulmonary manifestations of scleroderma and mixed connective tissue disease

Pulmonary manifestations are common in connective tissue diseases, and are associated with significant morbidity and mortality in this patient population. Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are clinical entities for which the detection of lung involvement is essential to improve patient care and outcomes. This article discusses the pathogenesis, clinical presentation, and evaluation of the patient with pulmonary disease related to SSc and MCTD, with an emphasis on interstitial lung disease and pulmonary hypertension.

Pulmonary Manifestations in Sjögren’s Syndrome: Correlation Analysis Between Chest Computed Tomographic Findings and Clinical Subsets with Poor Prognosis in 80 Patients

Objective.

Sjögren’s syndrome (SS) has a varied clinical spectrum and has been associated with various chest computed tomography (CT) findings. We sought to delineate the characteristic CT features in various subsets of SS, especially poor prognosis subsets.

Methods.

Retrospectively identified 80 never-smoker SS patients [56 primary SS (1-SS), 24 secondary SS (2-SS)] who underwent chest CT at our institution during a 3-year period from 2004 through 2007 were included in this study. Chest CT findings were qualitatively and semiquantitatively analyzed with comparison between 1-SS and 2-SS, and correlation with anti-SSB/La seropositivity and the presence of clonally derived lymphoproliferative disorder (cLPD), which are known to be pathognomonic and prognostic clinical features of SS patients.

Results.

All patients were women with median age of 60 years. Anti-SSB/La antibodies were found in 17 primary SS patients and 4 2-SS patients. Eleven patients with cLPD were identified and all of them had 1-SS. The most frequent CT finding in both types of patients was interlobular septal thickening. Secondary SS was associated with a significantly greater frequency and extent of honeycombing versus 1-SS. Univariate and multivariate analysis showed a significant association between honeycombing and 2-SS. In patients with 1-SS and in the SS group as a whole, we observed independent and significant associations between cysts and anti-SSB/La seropositivity or cLPD.

Conclusion.

Cysts are significantly associated with anti-SSB/La seropositivity and cLPD. The presence of lung cysts revealed by chest CT might be a prognostic clinical feature, a clue, or a predictor of cLPD in patients with SS.

Inflammatory cells in lung disease associated with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with numerous pulmonary manifestations. However, the inflammatory mechanism remains undetermined. We studied the features of inflammatory cells in bronchoalveolar lavage (BAL) fluid and biopsy lung tissue from patients with RA-associated lung disease.

METHODS

BAL findings were statistically compared between diseases. We divided RA patients into two groups, airway lesion group (AW) and interstitial lesion group (INT) according to predominant HRCT findings and compared the BAL findings. We immunohistochemically stained lung tissue for CD4, CD8, CD20, and CD163 and counted the immunopositive cells in five different regions.

PATIENTS

Twenty patients fulfilling the Japanese criteria for RA, 13 patients with systemic sclerosis (SSc), and 21 patients with polymyositis and dermatomyositis (PM-DM) with pulmonary disease detected by high-resolution CT (HRCT) were enrolled in this study.

RESULTS

As for BAL in RA, we found a lower lymphocyte frequency with higher CD4/8 ratio compared with PM-DM and a higher neutrophil percentage than both PM-DM and SSc. Nine and eleven patients with RA were classified into AW and INT groups, respectively. BAL findings did not differ between the two groups. Immunohistochemically, most CD4(+) and CD20(+) lymphocytes were accumulated in lymphoid follicles and in the alveolar wall and T-lymphocytes; in particular CD8(+) lymphocytes were predominant in lung interstitium.

CONCLUSION

These results suggest that 1) neutrophils may play an important role, 2) the inflammatory mechanism may be similar between airway lesion and interstitial pneumonia, and 3) CD8(+) lymphocytes may be major inflammatory cells in lung interstitium in RA-associated interstitial lung disease.

Nonspecific interstitial pneumonia associated with collagen vascular disease: analysis of CT features to distinguish the various types

OBJECTIVE

The purpose of this study was to analyze the CT findings of interstitial lung diseases that are associated with collagen vascular disease (CVD), with particular attention to nonspecific interstitial pneumonia (NSIP), and to examine whether it is possible to predict the clinical diagnosis of CVDs based on the CT findings alone.

METHODS

CT scans of 49 patients with NSIP associated with CVD (15 males, 34 females; mean age, 55+/-10 years; age range, 25-76 years) were included in this retrospective study. All patients underwent a surgical biopsy. The clinical diagnosis comprised rheumatoid arthritis (RA) (n=15), systemic sclerosis (SSc) (n=8), polymyositis and dermatomyositis (PM/DM) (n=18), Sjögren's syndrome (SjS) (n=4), and mixed connective tissue disease (MCTD) (n=4). Each CT was reviewed by two independent observers who made a clinical diagnosis based on the CT findings alone.

RESULTS

The observers made a correct diagnosis for 22 (45%) of the 49 patients. A correct diagnosis was made for: RA in 7 (47%) of 15 patients; SSc in 3 (38%) of 8 patients; PM/DM in 11 (61%) of 18 patients; SjS in 1 (25%) of 4 patients. None of the 4 MCTD cases was diagnosed.

CONCLUSION

It is difficult to make a correct clinical diagnosis of the various types of CVDs based solely on CT findings. However, it is probable to make a reasonably accurate clinical diagnosis in cases that show the typical CT findings, especially for PM/DM patients.

High-resolution CT scan findings in patients with symptomatic scleroderma-related interstitial lung disease

BACKGROUND

Lung disease has become the leading cause of mortality and morbidity in scleroderma (SSc) patients. The frequency, nature, and progression of interstitial lung disease seen on high-resolution CT (HRCT) scans in patients with diffuse SSc (dcSSc) compared with those with limited SSc (lcSSc) has not been well characterized.

METHODS

Baseline HRCT scan images of 162 participants randomized into a National Institutes of Health-funded clinical trial were compared to clinical features, pulmonary function test measures, and BAL fluid cellularity. The extent and distribution of interstitial lung disease HRCT findings, including pure ground-glass opacity (pGGO), pulmonary fibrosis (PF), and honeycomb cysts (HCs), were recorded in the upper, middle, and lower lung zones on baseline and follow-up CT scan studies.

RESULTS

HRCT scan findings included 92.9% PF, 49.4% pGGO, and 37.2% HCs. There was a significantly higher incidence of HCs in the three zones in lcSSc patients compared to dcSSc patients (p = 0.034, p = 0.048, and p = 0.0007, respectively). The extent of PF seen on HRCT scans was significantly negatively correlated with FVC (r = - 0.22), diffusing capacity of the lung for carbon monoxide (r = - 0.44), and total lung capacity (r = - 0.36). A positive correlation was found between pGGO and the increased number of acute inflammatory cells found in BAL fluid (r = 0.28). In the placebo group, disease progression was assessed as 30% in the upper and middle lung zones, and 45% in the lower lung zones. No difference in the progression rate was seen between lcSSc and dcSSc patients.

CONCLUSIONS

PF and GGO were the most common HRCT scan findings in symptomatic SSc patients. HCs were seen in more than one third of cases, being more common in lcSSc vs dcSSc. There was no relationship between progression and baseline PF extent or lcSSc vs dcSSc.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00004563.

Collagen Vascular Diseases and Disorders of Connective Tissue

The collagen vascular diseases, also referred to as connective tissue diseases, are a diverse group of systemic inflammatory disorders thought to be immunologically mediated. The concept of collagen vascular disease began to take shape in the 1930s, when it was recognized that rheumatic fever and rheumatoid arthritis can affect connective tissues throughout the body.1,2 During the following decade, as conditions such as systemic lupus erythematosus (SLE) and scleroderma came to be viewed as systemic diseases of connective tissue, the terms diffuse connective disease and diffuse collagen disease were proposed.3,4 During the same period, the designation of diffuse vascular disease was proposed for diseases such as scleroderma, polymyositis, SLE, and polyarteritis nodosa, which featured widespread vascular involvement.5 With the realization that many of these entities can exhibit both systemic connective tissue manifestations and vascular abnormalities, the unifying designation of collagen vascular disease was introduced.6

Isolation and immunophenotyping of mononuclear cells from human lung tissue

OBJECTIVE

To quantitatively isolate and immunologically phenotype mononuclear cells contained in human lung tissue.

METHODS

Normal appearing lung tissue as far distal to the resected lesion as possible was obtained from lung cancer patients. Lung tissue was thoroughly washed and cut into small pieces and digested with collagenase. Peripheral blood mononuclear cells (PBMNC) were prepared from controls using Ficoll gradient. Isolated cells and PBMNC were analyzed by flow cytometry. We immunohistochemically stained snap-frozen lung tissue with anti-CD3, CD4, CD8, CD20, and CD161 antibodies.

PARTICIPANTS

Nineteen patients with lung cancer who underwent lobectomy were enrolled. Twelve healthy volunteers also participated as controls for flow cytometric analysis of PBMNC.

RESULTS

In forward scatter vs side scatter, 92.1+/-7.8% of isolated cells in the lymphoid population expressed leukocyte common antigen, CD45. The frequency of CD45-positive cells in the lymphoid population from lung tissue was as high as that from PBMNC (p=0.118). CD45-positive cells were successfully further extended by anti-CD3, CD4, CD8, CD19, and CD161 antibodies. Monocyte-macrophages bearing CD68 were also detected. CD68-positive alveolar macrophages disappeared from alveolar spaces after thorough washing by immunohistochemical staining. Mononuclear cells in the interstitium were positively stained by anti-CD3, CD4, CD8, CD20, and CD161 monoclonal antibodies.

CONCLUSIONS

We could isolate interstitial cells and analyze cell surface markers via flow cytometry from fresh lung specimens by collagenase digestion without further purification. Immunohistochemistry confirmed the presence of the cells detected by flow cytometry in the lung interstitium.

Radionuclide imaging for the assessment of esophageal motility disorders in mixed connective tissue disease patients: relation to pulmonary impairment

Esophageal functional abnormalities may lead to regurgitation, chronic esophagitis and life-threatening conditions such as aspiration pneumonia. In mixed connective tissue disease patients, previous reports showed that esophageal dysfunction varies according to the method employed for investigation. Our study was conceived to: (i) assess esophageal motility and mucosal aspects in patients with mixed connective tissue disease by endoscopy, cine-esophogram and scintigraphy focusing on the prevalence of each exam; and (ii) verify the association between pulmonary and esophageal dysfunctions. Twenty-four mixed connective tissue disease patients were enrolled for this study. Cine-esophogram and upper digestive endoscopy with mucosal biopsy were performed according to previous standardization. Radionuclide esophageal scintigraphy was performed with a semisolid meal with (99m)Tc. Eleven healthy individuals voluntarily submitted to scintigraphy as controls. Cine-esophogram showed esophageal delayed emptying in 90% of patients. At scintigraphy there was a significant delay in total esophageal transit time in the group of patients when compared to healthy controls (35.3 +/- 8.2 s. vs. 13.6 +/- 9.5 s.; P < 0.0001). The whole esophageal body showed dysmotility in 96% of patients. The cine-esophogram detected functional esophageal impairment similar to scintigraphic findings. Histopathologic examination found esophagitis in 95% of studied patients. Reduced lung volumes were associated with esophagitis and delayed esophageal clearance at scintigraphy, observed at the distal portion of the esophagus. Esophageal scintigraphy is easy to perform, with good acceptance by patients with low radiation exposition. It is a useful non-invasive test for follow-up and interventional studies concerning esophagus dysfunction.

[Differential diagnosis of bronchiectasis: high-resolution CT as a valuable aide]

Bronchiectasis is defined as localized irreversible dilatation of the bronchial tree. Brochiectasis has been associated with a wide variety of causes, but it is mostly caused by acute, chronic or recurrent infections. This paper should give a review about the manifestation of bronchiectasis and bronchioloectasis in HR-CT and discuss the causing entities. However, integration of bronchiectasis and other HR-CT findings may enable a narrower differential diagnosis, in some cases it is possible to give the correct diagnose directly.

Pulmonale Manifestationen bei Erkrankungen des rheumatischen Formenkreises

Collagen based vascular diseases with pulmonary involvement comprise rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis, dermatomyositis and polymyositis, ankylosing spondylitis, Sjögren's syndrome, and mixed connective tissue diseases. The different characteristics of pulmonary involvement are described. In such circumstances, early recognition of lung involvement is of considerable significance and the relationship to the corresponding disease has to be made. Frequently unrecognised pulmonary involvement ends up as fibrosis with irreversible deficits in respiratory function.

Evaluation of interstitial lung disease in mixed connective tissue disease (MCTD)

OBJECTIVE

Interstitial lung disease (ILD) may be a characteristic, often serious, manifestation of mixed connective tissue disease (MCTD). In this retrospective study, the frequency and clinical picture of ILD were determined in patients with MCTD using two diagnostic tests: high-resolution computed tomography (HRCT) and inhaled aerosol clearance times of (99m)Tc-labelled diethylene-triamine pentaacetate ((99m)Tc-DTPA). In addition, pulmonary function, effects of therapy and a variety of immunoserological markers were also assessed.

METHODS

One hundred and forty-four consecutive patients with MCTD were selected from the clinic, irrespective of the presence or absence of ILD. All patients underwent a detailed clinical assessment, chest HRCT scanning, chest radiography, inhaled aerosol of (99m)Tc-DTPA clearance times, and all pulmonary function tests. Patients who had active ILD received corticosteroid (CS) or CS in combination with cyclophosphamide (CPH). All investigations were repeated after 6 months of immunosuppressive therapy.

RESULTS

Ninety-six out of 144 MCTD patients (66.6%) had active ILD, 75 of this group (78.1%) showed ground glass opacity, 21 patients (21.8%) ground glass opacity with mild fibrosis with HRCT. Forty-five patients with active ILD received 2 mg/kg/day CS for 6-8 weeks alone and 51 patients CS in combination with CPH (2 mg/kg/day). Six months later, after therapy, 67 out of 96 MCTD patients with ILD (69.8%) showed a negative HRCT pattern, ground glass opacity with mild fibrosis developed in 15 patients (15.6%), and fibrosis was detected in 13 patients (13.5%). Only one patient showed subpleural honeycombing. (99m)Tc-DTPA was rapid in all 96 MCTD patients with active ILD (28.7 +/- 8.2 min, normal value >40 min). After therapy the (99m)Tc-DTPA was normalized, 79 out of 96 patients (82.3%). Carbon monoxide diffusion capacity (DLCO) was reduced in 33 out of 96 MCTD patients with active ILD (34.3%), while there were no significant differences in the pulmonary function tests between the active versus inactive stage of ILD or versus patients without ILD. The sera of 96 MCTD patients with active ILD contained a high level of immune complexes (ICs), and the total haemolytic complement levels (CH50/ml U) decreased. After 6 months of therapy, the IC levels decreased and CH50/ml levels normalized (MCTD patients before and after active ILD: IC optical density = 355 +/- 227 vs 206 +/- 92, P<0.001; CH50/ml, 38.0 +/- 12.6 U vs 64.3 +/- 13.0 U, P<0.001).

CONCLUSIONS

HRCT is the gold standard for diagnosis of ILD. However, we used another method, (99m)Tc-DTPA, in order to compare this technique with HRCT. This latter technique has not been studied previously in MCTD. The elevated levels of IC and increased complement consumption indicated that IC-mediated alveolocapillary membrane damage and tissue injury might play a role in the pathogenesis of ILD in MCTD.

Interstitial lung disease in the patient who has connective tissue disease

Interstitial lung disease is a common complication of many of the connective tissue diseases. Because the prognosis, degree of reversibility, and optimal therapy differs for each disease presentation, a thorough knowledge of the pulmonary presentations of each connective tissue disease is important. Additionally, the challenge of finding the patient who has occult connective tissue disease in an interstitial lung disease clinic is discussed.

Mixed connective tissue disease with interstitial pneumonia in HTLV-1 carrier: case report and review of the literature

We report on a carrier of human T-lymphotropic virus type 1 (HTLV-1) who developed mixed connective tissue disease (MCTD). This patient suddenly manifested clinical symptoms and interstitial pneumonia ascribable to MCTD following long-term infection with HTLV-1. After initiation of oral prednisolone all manifestations quickly improved in parallel with a decrease in inflammatory reactions. In this patient HTLV-1 infection might have played an important role in the pathogenesis of MCTD. Since HTLV-1 can cause adult T-cell leukemia and HTLV-1-associated myelopathy, and also collagen diseases including MCTD, careful observation is necessary even in a carrier, particularly when autoantibodies are detectable in serum.

Cytokine regulation of pulmonary fibrosis in scleroderma

Pulmonary fibrosis occurs in up to 70% of scleroderma patients and progresses to cause severe restrictive lung disease in about 15% of patients. The mechanisms that cause pulmonary fibrosis in scleroderma remain incompletely understood. Increased amounts of mRNA or protein for multiple profibrotic cytokines and chemokines have been identified in lung tissue or broncholveolar lavage samples from scleroderma patients, when compared to healthy controls. These cytokines include transforming growth factor (TGF)-beta, connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), oncostatin M (OSM), monocyte chemotactic factor-1 and pulmonary and activation-regulated chemokine (PARC). Potential cellular sources of these profibrotic cytokines and chemokines in scleroderma lung disease include alternatively activated macrophages, activated CD8+ T cells, eosinophils, mast cells, epithelial cells and fibroblasts themselves. This review summarizes the literature on involvement of cytokines and chemokines in the development of pulmonary fibrosis in scleroderma.

Pulmonary disease in systemic lupus erythematosus and the antiphospholpid syndrome

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by disturbances in innate and adaptive immune mechanisms. Multiple systems and organs may be involved. Tissue damage and dysfunction are mediated by autoantibodies and immune complex formation. The lungs are among the organ systems commonly involved. The pulmonary manifestations usually occur in patients with multisystem disease and include: pleural involvement, parenchymal disease, pulmonary vascular disease and diaphragmatic dysfunction. Manifestations may range from sub-clinical abnormalities to life threatening disorders. Many of the pulmonary manifestations characteristic of SLE are seen in the antiphospholipid syndrome (APS) as well, in both the primary and secondary syndrome. In this review the diverse pulmonary manifestations are described as well as the diagnostic modalities available, including the use of induced sputum evaluation for early diagnosis and follow up. New treatment modalities are referred to.

High-resolution CT: what is it good for in pulmonary fibrosis?

For many radiologists and clinicians, high-resolution CT has become a useful tool in the diagnosis of diffuse lung disease, particularly in the diagnosis of idiopathic pulmonary fibrosis. This paper reviews the most recent literature on the usefulness of high-resolution CT in diagnosing, determining the subsequent prognosis, and guiding the care of patients with lung disease. Idiopathic lung diseases, collagen vascular diseases, and the role of lung biopsy in diffuse lung disease are addressed.

Occurrence of an activated, profibrotic pattern of gene expression in lung CD8+ T cells from scleroderma patients

OBJECTIVE

Pulmonary fibrosis is a major cause of death in scleroderma patients. Previous studies have shown an increase in CD8+ T cells in the lungs of scleroderma patients. In the present study, we sought to determine whether activated CD8+ T cells contribute to pulmonary fibrosis in scleroderma patients through the production and activation of profibrotic mediators.

METHODS

CD8+ cells were isolated from bronchoalveolar lavage fluid obtained from 19 scleroderma patients and 7 healthy subjects. The phenotype of these cells was determined using DNA array technology. Expression of selected genes was confirmed in real-time polymerase chain reaction and enzyme-linked immunosorbent assay experiments.

RESULTS

Hierarchical clustering of gene expression profiles revealed 2 groups of subjects. Group 1 consisted of 11 patients (8 with and 3 without lung inflammation). Group 2 consisted of 15 subjects (7 healthy controls and 2 patients with and 6 without lung inflammation). Gene expression in group 1 indicated T cell activation, a type 2 phenotype, production of profibrotic factors and matrix metalloproteinases, and reduced activation-induced cell death. Increased expression of beta6 integrin messenger RNA by CD8+ T cells in group 1 suggested the possibility that these T cells might induce cell-contact-dependent activation of latent transforming growth factor beta (TGFbeta).

CONCLUSION

A subset of scleroderma patients at higher risk of progressive lung disease have activated, long-lived CD8+ T cells in their lungs that could promote fibrosis directly, through production of profibrotic factors such as interleukin-4 and oncostatin M, as well as indirectly, through activation of TGFbeta.

Bronchoalveolar lavage fluid cells in mixed connective tissue disease

OBJECTIVE

Patients with mixed connective tissue disease (MCTD) exhibit clinical features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and polymyositis and dermatomyositis (PM-DM). The objective of this study was to clarify differences in BAL findings and immunophenotypes of BAL fluid (BALF) cells of patients with interstitial lung disease associated with these diseases.

METHODOLOGY

We were unable to recruit a sufficient number of SLE patients with lung disease. We compared immunophenotypes of lymphocytes and alveolar macrophages (AM) in BALF of 20 MCTD patients with those of 21 SSc and 27 PM-DM patients and tested the relationships between immunophenotypes and pulmonary function in MCTD.

RESULTS

MCTD patients had a significantly higher CD4/CD8 ratio with more CD4 positive lymphocytes than PM-DM patients (P = 0.025). In AM phenotypes, MCTD patients had a significantly lower percentage of CD71 positive AM compared with SSc patients (P = 0.023). DLCO was negatively related to absolute numbers of CD8 positive lymphocytes (R = -0.517, P= 0.033).

CONCLUSIONS

CD4 positive lymphocytes in BALF were increased in MCTD compared to PM-DM patients, while CD71 positive AM were decreased in MCTD compared to SSc patients. CD8 positive lymphocytes correlated negatively with DLCO measurements in MCTD patients.