Richard T. Meehan

Toll-like receptor 7 (TLR7)–driven accumulation of a novel CD11c + B-cell population is important for the development of autoimmunity

Females are more susceptible than males to many autoimmune diseases. The processes causing this phenomenon are incompletely understood. Here, we demonstrate that aged female mice acquire a previously uncharacterized population of B cells that we call age-associated B cells (ABCs) and that these cells express integrin α(X) chain (CD11c). This unexpected population also appears in young lupus-prone mice. On stimulation, CD11c(+) B cells, both from autoimmune-prone and healthy strains of mice, secrete autoantibodies, and depletion of these cells in vivo leads to reduction of autoreactive antibodies, suggesting that the cells might have a direct role in the development of autoimmunity. We have explored factors that contribute to appearance of ABCs and demonstrated that signaling through Toll-like receptor 7 is crucial for development of this B cell population. We were able to detect a similar population of B cells in the peripheral blood of some elderly women with autoimmune disease, suggesting that there may be parallels between the creation of ABC-like cells between mice and humans.

Mycophenolate Mofetil Improves Lung Function in Connective Tissue Disease-associated Interstitial Lung Disease

Objective. Small series suggest mycophenolate mofetil (MMF) is well tolerated and may be an effective therapy for connective tissue disease-associated interstitial lung disease (CTD-ILD). We examined the tolerability and longitudinal changes in pulmonary physiology in a large and diverse cohort of patients with CTD-ILD treated with MMF. Methods. We identified consecutive patients evaluated at our center between January 2008 and January 2011 and prescribed MMF for CTD-ILD. We assessed safety and tolerability of MMF and used longitudinal data analyses to examine changes in pulmonary physiology over time, before and after initiation of MMF. Results. We identified 125 subjects treated with MMF for a median 897 days. MMF was discontinued in 13 subjects. MMF was associated with significant improvements in estimated percentage of predicted forced vital capacity (FVC%) from MMF initiation to 52, 104, and 156 weeks (4.9% ± 1.9%, p = 0.01; 6.1% ± 1.8%, p = 0.0008; and 7.3% ± 2.6%, p = 0.004, respectively); and in estimated percentage predicted diffusing capacity (DLCO%) from MMF initiation to 52 and 104 weeks (6.3% ± 2.8%, p = 0.02; 7.1% ± 2.8%, p = 0.01). In the subgroup without usual interstitial pneumonia (UIP)-pattern injury, MMF significantly improved FVC% and DLCO%, and in the subgroup with UIP-pattern injury, MMF was associated with stability in FVC% and DLCO%. Conclusion. In a large diverse cohort of CTD-ILD, MMF was well tolerated and had a low rate of discontinuation. Treatment with MMF was associated with either stable or improved pulmonary physiology over a median 2.5 years of followup. MMF appears to be a promising therapy for the spectrum of CTD-ILD.

Mycophenolate mofetil versus oral cyclophosphamide in scleroderma-related interstitial lung disease (SLS II): a randomised controlled, double-blind, parallel group trial

Summary BACKGROUND Twelve months of oral cyclophosphamide (CYC) has been shown to alter the progression of scleroderma-related interstitial lung disease (SSc-ILD) when compared to placebo. However, toxicity was a concern and without continued treatment the efficacy disappeared by 24 months. We hypothesized that a two-year course of mycophenolate mofetil (MMF) would be safer, better tolerated and produce longer lasting improvements than CYC. METHODS Patients with SSc-ILD meeting defined dyspnea, pulmonary function and high-resolution computed tomography (HRCT) criteria were randomized in a double-blind, two-arm trial at 14 medical centers. MMF (target dose 1500 mg twice daily) was administered for 24 months in one arm and oral CYC (target dose 2·0 mg/kg/day) administered for 12 months followed by placebo for 12 months in the other arm. The primary endpoint, change in forced vital capacity as a percent of the predicted normal value (FVC %) over the course of 24 months, was assessed in a modified intention-to-treat analysis using an inferential joint model combining a mixed effects model for longitudinal outcomes and a survival model to handle non-ignorable missing data. The study was registered with ClinicalTrials.gov, number NCT00883129, and is closed. RESULTS Between November, 2009, and January, 2013, 142 patients were randomized. 126 patients (63 MMF; 63 CYC) with acceptable baseline HRCT studies and at least one outcome measure were included in the analysis. The adjusted FVC % (primary endpoint) improved from baseline to 24 months by 2.17 in the MMF arm (95% CI, 0.53–3.84) and 2·86 in the CYC arm (95% confidence interval 1·19–4·58) with no significant between-treatment difference (p=0·24), indicating that the trial was negative for the primary endpoint. However, in a post-hoc analysis of the primary endpoint, within-treatment improvements from baseline to 24 months were noted in both the CYC and MMF arms. A greater number of patients on CYC than on MMF prematurely withdrew from study drug (32 vs 20) and failed treatment (2 vs 0), and the time to stopping treatment was significantly shorter in the CYC arm (p=0·019). Sixteen deaths occurred (11 CYC; 5 MMF) with most due to progressive ILD. Leukopenia (30 vs 4 patients) and thrombocytopenia (4 vs 0 patients) occurred more often in patients treated with CYC. In post-hoc analyses, within- (but not between-) treatment improvements were also noted in defined secondary outcomes including skin score, dyspnea and whole-lung HRCT scores. INTERPRETATION Treatment of SSc-ILD with MMF for two years or CYC for one year both resulted in significant improvements in pre-specified measures of lung function, dyspnea, lung imaging, and skin disease over the 2-year course of the study. While MMF was better tolerated and associated with less toxicity, the hypothesis that it would have greater efficacy at 24 months than CYC was not confirmed. These findings support the potential clinical impact of both CYC and MMF for progressive SSc-ILD, as well as the current preference for MMF due to its better tolerability and toxicity profile. FUNDING National Heart, Lung and Blood Institute/National Institutes of Health with drug supply provided by Hoffmann-La Roche/Genentech.

Clinically Significant Interstitial Lung Disease in Limited Scleroderma: Histopathology, Clinical Features, and Survival

PURPOSES To evaluate the pathologic patterns, clinical features, and survival among subjects with scleroderma (ie, systemic sclerosis [SSc]) and clinically significant interstitial lung disease (ILD) evaluated at an ILD center. METHODS Retrospective cohort study of all SSc patients who had been referred for further evaluation of ILD and had undergone surgical lung biopsy. Clinical data were abstracted by review of the medical record, and lung biopsy specimens were reviewed and classified according to current pathologic criteria. RESULTS All patients presented with significant respiratory symptoms. Twenty-two of 27 subjects had surgical lung biopsy-proven ILD, and 5 subjects had miscellaneous non-ILD patterns. Of those subjects with ILD, 64% (14 of 22 subjects) had a nonspecific interstitial pneumonia (NSIP) pathologic pattern (fibrotic NSIP, 13 subjects; cellular NSIP, 1 subject), and 36% (8 of 22 subjects) had the usual interstitial pneumonia (UIP) pattern. Subjects with NSIP were younger (median age, 42 vs 58 years, respectively; p = 0.003), but no differences were noted in pulmonary physiology (FVC: NSIP group, 52% predicted; UIP group, 65% predicted; p = 0.22; diffusing capacity of the lung for carbon monoxide: NSIP group, 40% predicted; UIP group, 42% predicted; p = 1.0). All patients had limited skin involvement. The Scl-70 antibody was absent among those assessed (NSIP group, 0 of 10 subjects; UIP group, 0 of 7 subjects). All patients were treated with cytotoxic therapy. The median survival time for those with NSIP was 15.3 years (5,596 days) compared with 3 years (1,084 days) for those with UIP (p = 0.07 [log-rank test]). CONCLUSIONS In SSc patients with limited cutaneous disease and clinically significant ILD, fibrotic NSIP and UIP are the predominant pathologic patterns. Those with the UIP pattern of disease had a trend toward shorter survival time.

Pulmonary and Thrombotic Manifestations of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is considered the archetypal systemic autoimmune disease. Clinically characterized by multisystem involvement and varied serologic abnormalities, no two patients present or have disease that evolves in exactly the same way. Viewed histologically, SLE is characterized by some combination of inflammation and fibrosis, and the clinical phenotype is dictated by the relative contributions of each and the organs affected. Tissue injury appears to be mediated by characteristic autoantibody production, immune complex formation, and their organ-specific deposition. As expected in a multisystem disease, the entire pulmonary system is vulnerable to injury. Any of its compartments-airways, lung parenchyma, vasculature, pleura, or the respiratory musculature-may be independently or simultaneously affected. This article offers the reader a comprehensive review of the numerous pulmonary and thrombotic manifestations of SLE and suggests approaches to their management.

Original ResearchInterstitial Lung DiseaseClinically Significant Interstitial Lung Disease in Limited Scleroderma: Histopathology, Clinical Features, and Survival

PURPOSES To evaluate the pathologic patterns, clinical features, and survival among subjects with scleroderma (ie, systemic sclerosis [SSc]) and clinically significant interstitial lung disease (ILD) evaluated at an ILD center. METHODS Retrospective cohort study of all SSc patients who had been referred for further evaluation of ILD and had undergone surgical lung biopsy. Clinical data were abstracted by review of the medical record, and lung biopsy specimens were reviewed and classified according to current pathologic criteria. RESULTS All patients presented with significant respiratory symptoms. Twenty-two of 27 subjects had surgical lung biopsy-proven ILD, and 5 subjects had miscellaneous non-ILD patterns. Of those subjects with ILD, 64% (14 of 22 subjects) had a nonspecific interstitial pneumonia (NSIP) pathologic pattern (fibrotic NSIP, 13 subjects; cellular NSIP, 1 subject), and 36% (8 of 22 subjects) had the usual interstitial pneumonia (UIP) pattern. Subjects with NSIP were younger (median age, 42 vs 58 years, respectively; p = 0.003), but no differences were noted in pulmonary physiology (FVC: NSIP group, 52% predicted; UIP group, 65% predicted; p = 0.22; diffusing capacity of the lung for carbon monoxide: NSIP group, 40% predicted; UIP group, 42% predicted; p = 1.0). All patients had limited skin involvement. The Scl-70 antibody was absent among those assessed (NSIP group, 0 of 10 subjects; UIP group, 0 of 7 subjects). All patients were treated with cytotoxic therapy. The median survival time for those with NSIP was 15.3 years (5,596 days) compared with 3 years (1,084 days) for those with UIP (p = 0.07 [log-rank test]). CONCLUSIONS In SSc patients with limited cutaneous disease and clinically significant ILD, fibrotic NSIP and UIP are the predominant pathologic patterns. Those with the UIP pattern of disease had a trend toward shorter survival time.

Minor salivary gland biopsy to detect primary Sjogren syndrome in patients with interstitial lung disease.

PURPOSES To describe a cohort of patients who presented with interstitial lung disease (ILD) of unknown cause, features of primary Sjögren syndrome (pSS), and a positive minor salivary gland biopsy (MSGB). METHODS Thirty-eight patients with ILD evaluated at our center underwent an MSGB to confirm a diagnosis of pSS. All of the samples were reviewed by pathologists experienced in the evaluation of salivary gland histology. We defined a positive MSGB finding as a lymphocyte focus score of >1. RESULTS At presentation, all patients had ILD, and symptoms of cough and dyspnea. None had a definable connective tissue disease (CTD) or known cause for their ILD. Thirteen patients (34%) had positive MSGB findings. Of these, the median age was 61 years (age range, 33 to 75 years); 7 patients (54%) were women; 8 patients (62%) had a smoking history; and 10 patients (77%) had sicca symptoms. In all patients, a thoracic high-resolution CT scan evaluation demonstrated bibasilar, peripheral-predominant, ground-glass, and reticular opacities. Four patients (31%) were negative for both antinuclear autoantibody (ANA) and rheumatoid factor (RF) autoantibody, and three patients (23%) were negative for ANA, RF, Sjögren syndrome (SS)-A, and SS-B autoantibodies. No patients experienced any complications from the MSGB. The identification of underlying pSS did not affect the management of ILD in these patients. CONCLUSIONS Confirming a diagnosis of pSS-related ILD by performing MSGB allows for a more precise CTD classification. This study provides evidence that CTD may exist subclinically, and longitudinal studies are needed to determine whether identifying occult CTD impacts on management, longitudinal changes in lung function, or survival.

Systemic Lupus Erythematosus-Related Interstitial Lung Disease

Systemic lupus erythematosus (SLE) is a systemic, inflammatory disorder with a predilection for young women. A wide array of pulmonary manifestations can occur in patients with SLE, including interstitial lung disease. In this review, we will discuss the scope, pathogenesis, management, and prognosis, along with the clinical and pathologic features of SLE-associated ILD (SLE-ILD).