Fredrick M. Wigley

Production of type 2 cytokines by CD8+ lung cells is associated with greater decline in pulmonary function in patients with systemic sclerosis

OBJECTIVE This study addresses the hypothesis that a profibrotic pattern of cytokines is produced in the lungs of patients with systemic sclerosis (SSc) and causes fibrosis. METHODS Using a reverse transcriptase-polymerase chain reaction technique, interleukin-4 (IL-4), IL-5, and interferon-gamma (IFNgamma) messenger RNA (mRNA) were measured in unseparated CD8+ and CD4+ bronchoalveolar lavage (BAL) cells from SSc patients and healthy controls. To confirm the results, CD8+ T cells were cloned from BAL fluids, and the pattern of cytokine mRNA made by these cells was determined. Serial pulmonary function tests were done. RESULTS BAL cells from healthy controls made IFNgamma mRNA, with no or little IL-4 or IL-5 mRNA. In contrast, BAL cells from the majority of SSc patients made IL-4 and/or IL-5 mRNA, with or without approximately equal amounts of IFNgamma mRNA. This pattern of cytokines was made by CD8+ T cells, which were increased in the lungs of these SSc patients. Patients whose BAL cells made this type 2 pattern of cytokine mRNA had a significant decline in forced vital capacity over time after the BAL, whereas patients whose BAL cells made IFNgamma mRNA alone did not. Both wild-type and an alternative splice variant of IL-4 mRNA were increased in BAL cells from SSc patients. Both forms of IL-4 stimulated alpha2(I) collagen mRNA in human dermal and lung fibroblasts. CONCLUSION The type 2 pattern of cytokine mRNA produced by BAL cells from SSc patients differs from unopposed IFNgamma production found in healthy BAL cells. This production of type 2 cytokine mRNA by CD8+ T cells is associated with a significant decline in lung function over time, which suggests a pathologic role for these T cells in interstitial fibrosis in SSc.

Association of the autoimmune disease scleroderma with an immunologic response to cancer.

Cancer Immunosurveillance Gone Bad? A subset of patients who develop scleroderma, a debilitating autoimmune disease, have an elevated risk of developing cancer. These patients harbor autoantibodies to RPC1, an RNA polymerase subunit encoded by the POLR3A gene. Joseph et al. (p. 152, published online December 5; see the Perspective by Teng and Smyth) explored whether the RPC1 autoantibodies target a “foreign” antigen derived from a mutated POLR3A gene. Sequence analysis revealed that POLR3A mutations were present in tumors from six of eight patients with RPC1 autoantibodies but in no tumors from eight control patients who lacked RPC1 autoantibodies. Cell culture data suggested that the POLR3A mutations triggered cellular and humoral immune responses in the patients. These results provide support for the “immunosurveillance” hypothesis, which posits the continual eradication of nascent tumor cells via immune responses. The immune system’s response to a mutant protein produced by an incipient cancer may help to explain an autoimmune disease. [Also see Perspective by Teng and Smyth] Autoimmune diseases are thought to be initiated by exposures to foreign antigens that cross-react with endogenous molecules. Scleroderma is an autoimmune connective tissue disease in which patients make antibodies to a limited group of autoantigens, including RPC1, encoded by the POLR3A gene. As patients with scleroderma and antibodies against RPC1 are at increased risk for cancer, we hypothesized that the “foreign” antigens in this autoimmune disease are encoded by somatically mutated genes in the patients’ incipient cancers. Studying cancers from scleroderma patients, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to RPC1 but not in eight patients without antibodies to RPC1. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations triggered cellular immunity and cross-reactive humoral immune responses. These results offer insight into the pathogenesis of scleroderma and provide support for the idea that acquired immunity helps to control naturally occurring cancers.

Survival in pulmonary hypertension associated with the scleroderma spectrum of diseases: Impact of interstitial lung disease

OBJECTIVE Pulmonary hypertension (PH) is an important cause of mortality in systemic sclerosis (SSc), where it can be isolated (pulmonary arterial hypertension [PAH]) or associated with interstitial lung disease (ILD). This study was undertaken to characterize determinants of survival among SSc patients with either type of PH who received PAH-specific therapy. METHODS Consecutive SSc patients with PAH or ILD-associated PH confirmed by right heart catheterization were included in the study. Kaplan-Meier and Cox proportional hazards models were used to compare survival between SSc patients with PAH and those with ILD-associated PH and to identify predictors of survival. RESULTS Fifty-nine patients (39 with PAH and 20 with ILD-associated PH) were identified. The majority (15 of 20 with ILD-associated PH and 27 of 39 with PAH) received an endothelin receptor antagonist as initial therapy. Median followup time was 4.4 years (range 2.7-7.4 years). Survival was significantly worse in SSc patients with ILD-associated PH than in those with PAH (1-, 2-, and 3-year survival rates 82%, 46%, and 39% versus 87%, 79%, and 64%, respectively; P < 0.01 by log rank test). In a multivariable analysis, ILD-associated PH was associated with a 5-fold increase in risk of death compared with PAH. Pulmonary vascular resistance index was also an independent predictor of mortality in the overall cohort (hazard ratio 1.05, P < 0.01) and was a significant univariable risk factor in each group separately. Type of initial PAH therapy and the use of warfarin were not related to survival. CONCLUSION Survival in SSc complicated by PH remains poor despite currently available treatment options. While therapy may be associated with improved survival in PAH compared with historical controls, the prognosis for patients with ILD-associated PH is particularly grim. Early diagnosis and treatment may improve outcomes since worsening hemodynamic factors were associated with reduced survival.

Close temporal relationship between onset of cancer and scleroderma in patients with RNA polymerase I/III antibodies

OBJECTIVE This study was undertaken to examine the temporal relationship between scleroderma development and malignancy, and to evaluate whether this differs by autoantibody status among affected patients. METHODS Study participants had a diagnosis of scleroderma, a diagnosis of cancer, cancer, an available serum sample, and a cancer pathology specimen. Sera were tested for autoantibodies against topoisomerase I, centromere, and RNA polymerase I/III by immunoprecipitation and/or enzyme-linked immunosorbent assay. Clinical and demographic characteristics were compared across autoantibody categories. Expression of RNA polymerases I and III was evaluated by immunohistochemistry using cancerous tissue from patients with anti-RNA polymerase antibodies. RESULTS Twenty-three patients were enrolled. Six patients tested positive for anti-RNA polymerase I/III, 5 for anti-topoisomerase I, and 8 for anticentromere, and 4 were not positive for any of these antigens. The median duration of scleroderma at cancer diagnosis differed significantly between groups (-1.2 years in the anti-RNA polymerase I/III group, +13.4 years in the anti-topoisomerase I group, +11.1 years in the anticentromere group, and +2.3 years in the group that was negative for all antigens tested) (P = 0.027). RNA polymerase III demonstrated a robust nucleolar staining pattern in 4 of 5 available tumors from patients with antibodies to RNA polymerase I/III. In contrast, nucleolar RNA polymerase III staining was not detected in any of 4 examined tumors from the RNA polymerase antibody-negative group (P = 0.048). CONCLUSION Our findings indicate that there is a close temporal relationship between the onset of cancer and scleroderma in patients with antibodies to RNA polymerase I/III, which is distinct from scleroderma patients with other autoantibody specificities. In this study, autoantibody response and tumor antigen expression are associated. We propose that malignancy may initiate the scleroderma-specific immune response and drive disease in a subset of scleroderma patients.

Vascular Disease in Scleroderma

Although scleroderma is generally considered a fibrosing disease of the tissues, it is now recognized that the underlying vascular disease is playing a fundamental role in its pathogenesis and associated tissue injury. The exact mechanism for the widespread scleroderma vascular disease is still unknown, but endothelial cell injury induced by infection, immune-mediated cytotoxicity, antiendothelial antibodies, and/or ischemia-reperfusion have all been implicated. The downstream effects of blood vessel perturbation produce “biomarkers” of vascular damage that reflect disease and may predict clinical outcomes. A complex interaction between endothelial cells, smooth muscle cells, extracellular matrix, and intravascular circulating factors is now recognized to contribute to the vascular reactivity, remodeling, and occlusive disease of scleroderma. Understanding the mechanisms underlying these processes provides rationale of novel therapeutic strategies and specific targeted therapy. This review will outline some of the evidence for the causes and consequences of scleroderma vascular disease.

The impact of pain and symptoms of depression in scleroderma

&NA; Systemic sclerosis (scleroderma) is a rare connective tissue disease that can affect multiple organ systems. Case reports and small treatment studies suggest that pain is significant in scleroderma, but few data speak of the frequency or impact of pain. This study sought to determine the frequency and impact of pain, symptoms of depression, and social network characteristics on physical functioning and social adjustment in patients with scleroderma. One hundred and forty‐two scleroderma patients completed measures of pain, depressive symptoms, social network characteristics, physical functioning, and social adjustment. Sixty‐three percent reported at least mild pain and 50% reported at least mild levels of depressive symptomatology. Hierarchical regression analyses revealed that pain, depressive symptoms, and employment status (disabled/unemployed vs. not) were significant, independent predictors of physical functioning, together accounting for 37% of the total variance. Pain was the single strongest predictor of physical function, accounting for 20% of the variance. Depressive symptoms, physical functioning, diversity of social network, and employment status were significant independent predictors of social adjustment, together accounting for 63% of the variance. Depressive symptoms were the single strongest predictor of social adjustment, accounting for 26% of the variance. The effects of pain and physical function on social adjustment became non‐significant when depressive symptoms were entered into the model, suggesting that symptoms of depression mediate the effect of pain and physical function on social adjustment. These findings indicate that pain is common in scleroderma and that pain and depressive symptoms are significant determinants of physical functioning and social adjustment, two important components of health‐related quality of life. Increased attention to effective management of pain and symptoms of depression in scleroderma will likely lead to improved functioning and quality of life.

MQX-503, a novel formulation of nitroglycerin, improves the severity of Raynaud's phenomenon: A randomized, controlled trial†

OBJECTIVE Raynauds phenomenon (RP) affects 3-9% of the general population and >90% of patients with systemic sclerosis. Nitrates are often prescribed for the treatment of RP, but currently available formulations are limited by side effects, particularly headaches, dizziness, and skin irritation. The purpose of this study was to evaluate the tolerability and efficacy of a novel formulation of topical nitroglycerin, MQX-503, in the treatment of RP in an ambulatory setting. METHODS We conducted a multicenter, randomized, placebo-controlled study with a 2-week single-blind run-in period to determine baseline severity, followed by a 4-week double-blind treatment phase. Two hundred nineteen adult patients with a clinical diagnosis of primary or secondary RP received 0.9% MQX-503 gel or matching placebo during the treatment period. Gel was applied immediately before or within 5 minutes of the beginning of an episode of RP (maximum of 4 applications daily). End points included the change in the mean Raynauds Condition Score (RCS; scale 0-10), the frequency and duration of episodes, and subjective assessments at the target week (the week during the treatment phase that most closely matched the run-in period in terms of ambient temperature) compared with baseline. RESULTS The mean (%) change in the RCS at the target week compared with baseline was significantly greater in the MQX-503 group (0.48 [14.3%]) than that in the placebo group (0.04 [1.3%]; P = 0.04). Changes in the frequency and duration of RP episodes and subjective assessments were not statistically different between the groups. MQX-503 had a side effect profile similar to that of placebo. CONCLUSION MQX-503 is well tolerated and more effective than placebo for the treatment of RP.

Serial pulmonary function in systemic sclerosis

The natural history of the pulmonary involvement in systemic sclerosis is not well studied. Reported here are the serial measurements of pulmonary function in a well defined population of patients with systemic sclerosis followed over a mean of 63 months. The mean rate of loss of vital capacity (0.10 liters per year) for the 38 patients serially studied was more than three times the expected rate of loss for a normal population. The mean rate of loss of diffusing capacity (0.33 ml/min/mm Hg per year) for the 27 patients serially studied was similar to that for a normal population. The percent forced vital capacity expired in the first second increased 0.53 percent per year consistent with a progressive restrictive ventilatory defect. Smokers tended to lose vital capacity at a slightly greater rate than nonsmokers (p = 0.069). Individual variability in the course of pulmonary function was observed. Although the overall trend in our population was towards a slowly progressive restrictive ventilatory defect, pulmonary function in the nonsmokers did not change at rates different from those in a nonsmoking reference population.

The DNA mismatch repair enzyme PMS1 is a myositis-specific autoantigen.

OBJECTIVE The specificity of the autoantibody response in different autoimmune diseases makes autoantibodies useful for diagnostic purposes. It also focuses attention on tissue- and event-specific circumstances that may select unique molecules for an autoimmune response in specific diseases. Defining additional phenotype-specific autoantibodies may identify such circumstances. This study was undertaken to investigate the disease specificity of PMS1, an autoantigen previously identified in some sera from patients with myositis. METHODS We used immunoprecipitation analysis to determine the frequency of autoantibodies to PMS1 in sera from patients with myositis, systemic lupus erythematosus, or scleroderma and from healthy controls. Additional antigens recognized by PMS1-positive sera were further characterized in terms of their susceptibility to cleavage by apoptotic proteases. RESULTS PMS1, a DNA mismatch repair enzyme, was identified as a myositis-specific autoantigen. Autoantibodies to PMS1 were found in 4 of 53 patients with autoimmune myositis (7.5%), but in no sera from 94 patients with other systemic autoimmune diseases (P = 0.016). Additional mismatch repair enzymes (PMS2, MLH1) were targeted, apparently independently. Sera recognizing PMS1 also recognized several other proteins involved in DNA repair and remodeling, including poly(ADP-ribose) polymerase, DNA-dependent protein kinase, and Mi-2. All of these autoantigens were efficiently cleaved by granzyme B, generating unique fragments not observed during other forms of cell death. CONCLUSION PMS1 autoantibodies are myositis specific. The striking correlation between an immune response to a group of granzyme B substrates (functioning in DNA repair and remodeling) and the myositis phenotype strongly implies that tissue- and event-specific biochemical events play a role in selecting these molecules for an autoimmune response. Understanding the role of granzyme B cleavage in this response is an important priority.

Independent association of anti–β2-glycoprotein I antibodies with macrovascular disease and mortality in scleroderma patients

OBJECTIVE Systemic sclerosis (SSc; scleroderma) is characterized by a unique widespread vascular involvement that can lead to severe digital ischemia, pulmonary arterial hypertension (PAH), or other organ dysfunction. Microthrombotic events and procoagulation factors such as anti-beta2-glycoprotein I (anti-beta2GPI) or anticardiolipin antibodies (aCL) may be implicated in the development of these manifestations. This study was undertaken to investigate whether anti-beta2GPI and aCL are correlated with macrovascular disease, including ischemic digital loss and PAH, in SSc patients. METHODS Seventy-five SSc patients with a history of ischemic digital loss and 75 matched SSc controls were evaluated. Anticentromere antibodies (ACAs), anti-beta2GPI, and aCL were measured, and clinical associations were determined using conditional and simple logistic regression models. RESULTS Positivity for anti-beta2GPI was significantly more frequent in SSc patients with digital loss than in patients without digital loss (P=0.017), with the IgA isotype of anti-beta2GPI showing the strongest association (odds ratio [OR] 4.0). There was no significant difference in aCL frequency between patients with digital loss and control patients. After adjustment for demographic characteristics, disease type, smoking, and ACA, anti-beta2GPI positivity was significantly associated with active digital ischemia (OR 9.4), echocardiographically evident PAH (OR 4.8), and mortality (OR 2.9). ACA positivity was associated with history of digital loss (OR 3.28), but not with PAH or mortality. History of digital loss was strongly associated with increased mortality (OR 12.5). CONCLUSION Anti-beta2GPI is significantly associated with macrovascular disease in SSc and independently predicts mortality. It is unclear whether it has a pathogenetic role or simply reveals the presence of underlying endothelial injury. The use of anti-beta2GPI as a biomarker of vascular disease in SSc should be further explored.