Assessment of risks of pulmonary infection during 12 months following immunosuppressive treatment for active connective tissue diseases: a large-scale prospective cohort study

OBJECTIVE

Pulmonary infections (PI) are leading causes of death in patients with connective tissue diseases (CTD). The PREVENT study (Pulmonary infections in patients REceiving immunosuppressiVE treatmeNT for CTD) assessed risk of PI in patients with active CTD in the contemporary era of advanced immunosuppressive therapy.

METHODS

In patients who started corticosteroids (n = 763), conventional immunosuppressants or biologics for active CTD were enrolled. Clinical and laboratory data, usage of drugs, and occurrence of PI were collected for 12 months. Baseline risk factors were investigated using Cox regression analysis. A nested case-control (NCC) study was performed with 1:2 matched case-control pairs to assess the risk for each drug category.

RESULTS

During the observation period, 32 patients died (4.2%) and 66 patients were lost to followup (8.6%). Patients with PI (n = 61, 8%) had a significantly worse accumulated survival rate than patients without (p < 0.01). Cox hazard regression analysis using baseline data showed that these factors were significantly associated with PI: age ≥ 65 years (HR 3.87, 95% CI 2.22-6.74), ≥ 20 pack-years of smoking (2.63, 1.37-5.04), higher serum creatinine level (1.21, 1.05-1.41 per 1.0 mg/dl increase), and maximum prednisolone (PSL) dose during the first 2 weeks of treatment (2.81, 1.35-5.86 per 1.0 mg/kg/day increase). Logistic regression analysis by an NCC study revealed that maximum PSL dose within 14 days before PI (OR 4.82, 95% CI 1.36-17.01 per 1.0 mg/dl increase; 2.57, 1.28-5.16 if ≥ 0.5 mg/kg/day) was significantly associated with the events, while other immunosuppressants were not.

CONCLUSION

Physicians should be aware of the higher risks for corticosteroids of PI than other immunosuppressants and assess these risk factors before immunosuppressive treatment, to prevent PI.

Pulmonary infections following immunosuppressive treatments during hospitalization worsen the short-term vital prognosis for patients with connective tissue disease-associated interstitial pneumonia

OBJECTIVE

Connective tissue disease-associated interstitial pneumonia (CTD-IP) significantly affects the mortality of patients with CTD. The purpose of the present study is to identify causes and risk factors for death during hospitalization for immunosuppressive treatment of CTD-IP.

METHODS

A multicenter, retrospective study was conducted that collected data from patients with CTD who had been hospitalized for commencing or intensifying immunosuppressive treatment of CTD-IP using a standardized case report form. Risk factors were identified using the Cox proportional hazard regression model.

RESULTS

A total of 322 CTD-IP patients were enrolled with rheumatoid arthritis (n = 84), systemic lupus erythematosus (n = 13), polymyositis (n = 33), dermatomyositis (n = 69), systemic sclerosis (n = 55), mixed connective tissue disease (n = 21), microscopic polyangiitis (n = 19), and overlap syndrome (n = 28). Of the 42 patients who died during hospitalization, 22 died from CTD-IP, 15 from CTD-IP and pulmonary infection, 2 from pulmonary infection, and 3 from other causes. Age ≥ 65 years and development of pulmonary infections after commencing or intensifying immunosuppressive treatments were identified as risk factors for death during hospitalization after adjusting for covariates.

CONCLUSION

Careful consideration of the benefit-risk balance of immunosuppressive treatment for CTD-IP is indispensable for improving the short-term vital prognosis of these patients.

Perillyl alcohol suppresses antigen-induced immune responses in the lung

Perillyl alcohol (POH) is an isoprenoid which inhibits farnesyl transferase and geranylgeranyl transferase, key enzymes that induce conformational and functional changes in small G proteins to conduct signal production for cell proliferation. Thus, it has been tried for the treatment of cancers. However, although it affects the proliferation of immunocytes, its influence on immune responses has been examined in only a few studies. Notably, its effect on antigen-induced immune responses has not been studied. In this study, we examined whether POH suppresses Ag-induced immune responses with a mouse model of allergic airway inflammation. POH treatment of sensitized mice suppressed proliferation and cytokine production in Ag-stimulated spleen cells or CD4(+) T cells. Further, sensitized mice received aerosolized OVA to induce allergic airway inflammation, and some mice received POH treatment. POH significantly suppressed indicators of allergic airway inflammation such as airway eosinophilia. Cytokine production in thoracic lymph nodes was also significantly suppressed. These results demonstrate that POH suppresses antigen-induced immune responses in the lung. Considering that it exists naturally, POH could be a novel preventive or therapeutic option for immunologic lung disorders such as asthma with minimal side effects.

Suppression of experimental autoimmune encephalomyelitis by interleukin-10 transduced neural stem/progenitor cells

Neural stem/progenitor cells (NSPCs) have the ability to migrate into the central nervous system (CNS) to replace damaged cells. In inflammatory CNS disease, cytokine transduced neural stem cells may be used as vehicles to specifically reduce inflammation and promote cell replacement. In this study, we used NSPCs overexpressing IL-10, an immunomodulatory cytokine, in an animal model for CNS inflammation and multiple sclerosis (MS). Intravenous injection of IL-10 transduced neural stem/progenitor cells (NSPC^IL-10) suppressed myelin oligodendrocyte glycoprotein aa 35–55 (MOG35-55)- induced experimental autoimmune encephalomyelitis (EAE) and, following intravenous injection, NSPC^IL-10 migrated to peripheral lymphoid organs and into the CNS. NSPC^IL-10 suppressed antigen-specific proliferation and proinflammatory cytokine production of lymph node cells obtained from MOG35-55 peptide immunized mice. In this model, IL-10 producing NSPCs act via a peripheral immunosuppressive effect to attenuate EAE.

Alendronate attenuates eosinophilic airway inflammation associated with suppression of Th2 cytokines, Th17 cytokines, and eotaxin-2

Bisphosphonates (BPs) have been widely used to treat osteoporosis. They act by inhibiting farnesyl diphosphate synthase in the mevalonate pathway. This resembles the action of statins, whose immune-modulating effect has recently been highlighted. In contrast, the effect of BPs on immune responses has not been elucidated well. In this study, we examined the effect of alendronate (ALN), a nitrogen-containing BP, on allergic airway inflammation in a mouse model. BALB/c mice were sensitized twice with OVA and challenged three times with nebulized OVA to induce eosinophilic airway inflammation. ALN was administered by an intragastric tube before each inhalation. ALN strongly suppressed airway eosinophilia and Th2, as well as Th17 cytokine production in the lung. ALN also attenuated eotaxin-2 production in the lung. Immunohistochemistry demonstrated that the major cell source of eotaxin-2 was peribronchial/perivascular macrophages, and flow cytometrical studies confirmed that ALN decreased eotaxin-2 expression in these macrophages. Furthermore, ALN attenuated eotaxin-2 production from mouse pleural macrophages and human monocyte/macrophage-like THP-1 cells in vitro. These results suggest that ALN suppressed Ag-induced airway responses in the mouse model. The suppression of eotaxin-2 production from macrophages appears to be one of ALN's immunomodulatory effects, whereas the mechanism by which ALN suppressed Th2 and Th17 responses could not be fully elucidated in this study. Although a clinical study should be conducted, ALN could be a novel therapeutic option for asthma.

Elevation of KL-6 serum levels in clinical trials of tumor necrosis factor inhibitors in patients with rheumatoid arthritis: a report from the Japan College of Rheumatology Ad Hoc Committee for Safety of Biological DMARDs

OBJECTIVE

The associations between elevated levels of serum Krebs von den Lungen-6 (KL-6) and treatment of rheumatoid arthritis (RA) with tumor necrosis factor (TNF) inhibitors were investigated in five Japanese clinical trials.

METHODS

Percentages and incidence rates were calculated for elevated serum KL-6 levels. Adverse events associated with elevated levels of serum KL-6 were investigated.

RESULTS

In RISING, a clinical trial for infliximab, 15.6 % of the enrolled patients met criterion B (KL-6 ≥500 U/ml and >1.5-fold increase over the baseline value) by week 54. In HIKARI, 7.8 % of the certolizumab pegol (CZP) group and 0 % of the placebo group met criterion B during the double-blind (DB) period (p = 0.003). In J-RAPID, 8.4 % of the methotrexate (MTX) + CZP and 3.9 % of the MTX + placebo groups met criterion B during the DB period. In GO-MONO, 1.8 % of the golimumab (GLM) and 1.3 % of the placebo groups met criterion B during the DB period. In GO-FORTH, 7.1 % of the MTX + GLM and 0 % of the MTX + placebo groups met criteron B during the DB period (p = 0.017). No adverse events accompanied the elevation of serum KL-6 levels in 95.7 % of these patients.

CONCLUSION

Serum KL-6 levels may increase during anti-TNF therapy without significant clinical events. In these patients, continuing treatment with TNF inhibitors under careful observation is a reasonable option.

A retrospective study of serum KL-6 levels during treatment with biological disease-modifying antirheumatic drugs in rheumatoid arthritis patients: a report from the Ad Hoc Committee for Safety of Biological DMARDs of the Japan College of Rheumatology

OBJECTIVE

We investigated associations between treatment with methotrexate (MTX) or biological disease-modifying antirheumatic drugs (DMARDs) and elevation of serum Krebs von den Lungen-6 (KL-6) levels in Japanese patients with rheumatoid arthritis (RA).

METHODS

Using a standardized form, data were collected retrospectively from medical records and analyzed descriptively.

RESULTS

Of a total of 198 RA patients with KL-6 serum levels measured at initiation of treatment (month 0) and two or more times by month 12, 27 (17.9 %) of 151 RA patients treated with biological DMARDs, including infliximab, etanercept, adalimumab, and tocilizumab (the biological DMARDs group), and 5 (10.6 %) of 47 patients treated without biological DMARDs but with MTX (MTX group), met criterion B (max. KL-6 ≥500 U/ml and >1.5-fold from baseline) by 12 months. The majority of patients (n = 28) meeting criterion B had no apparent interstitial lung disease or malignancy. Of these 28 patients, 21 had serum KL-6 levels available after reaching their maximum level, and 13 (61.9 %) of the 21 then met criterion R [decrease to less than 500 U/ml or to less than (baseline + 0.5 × (maximum - baseline))] by month 12.

CONCLUSION

Serum KL-6 levels may increase during treatment with MTX or these biological DMARDs without significant clinical events.

cGMP-dependent protein kinase I is involved in neurite outgrowth via a Rho effector, rhotekin, in Neuro2A neuroblastoma cells

Although the cGMP/cGMP-dependent protein kinase (cGK) signaling is involved in the regulation of neurite outgrowth, its mechanism remains to be clarified. In this study, we identified a Rho effector, rhotekin, as a cGK-I-interacting protein. Rhotekin was also a substrate for cGK-Iα. In neurite-extended Neuro2A neuroblastoma cells, cGK-Iα and rhotekin were colocalized in the plasma membrane and extended neurites, while treatment with cGMP resulted in translocation of rhotekin to the cytoplasm. In addition, we found that cGK-Iα and rhotekin synergistically suppressed Rho-induced neurite retraction. Our findings suggest that cGK-Iα interacts with and phosphorylates rhotekin, thereby contributing to neurite outgrowth regulation.

High expression of IL-22 suppresses antigen-induced immune responses and eosinophilic airway inflammation via an IL-10-associated mechanism

Allergic inflammation in the airway is generally considered a Th2-type immune response. However, Th17-type immune responses also play important roles in this process, especially in the pathogenesis of severe asthma. IL-22 is a Th17-type cytokine and thus might play roles in the development of allergic airway inflammation. There is increasing evidence that IL-22 can act as a proinflammatory or anti-inflammatory cytokine depending on the inflammatory context. However, its role in Ag-induced immune responses is not well understood. This study examined whether IL-22 could suppress allergic airway inflammation and its mechanism of action. BALB/c mice were sensitized and challenged with OVA-Ag to induce airway inflammation. An IL-22-producing plasmid vector was delivered before the systemic sensitization or immediately before the airway challenge. Delivery of the IL-22 gene before sensitization, but not immediately before challenge, suppressed eosinophilic airway inflammation. IL-22 gene delivery suppressed Ag-induced proliferation and overall cytokine production in CD4(+) T cells, indicating that it could suppress Ag-induced T cell priming. Antagonism of IL-22 by IL-22-binding protein abolished IL-22-induced immune suppression, suggesting that IL-22 protein itself played an essential role. IL-22 gene delivery neither increased regulatory T cells nor suppressed dendritic cell functions. The suppression by IL-22 was abolished by deletion of the IL-10 gene or neutralization of the IL-10 protein. Finally, IL-22 gene delivery increased IL-10 production in draining lymph nodes. These findings suggested that IL-22 could have an immunosuppressive effect during the early stage of an immune response. Furthermore, IL-10 plays an important role in the immune suppression by IL-22.

Dopamine D1-like receptor antagonist attenuates Th17-mediated immune response and ovalbumin antigen-induced neutrophilic airway inflammation

Allergic airway inflammation is generally considered a Th2-type immune response. Recent studies, however, demonstrated that Th17-type immune responses also play important roles in this process, especially in the pathogenesis of neutrophilic airway inflammation, a hallmark of severe asthma. We previously reported that dendritic cells release dopamine to naive CD4(+) T cells in Ag-specific cell-cell interaction, in turn inducing Th17 differentiation through dopamine D1-like receptor (D1-like-R). D1-like-R antagonist attenuates Th17-mediated diseases such as experimental autoimmune encephalomyelitis and autoimmune diabetes. However, the effect of antagonizing D1-like-R on Th17-mediated airway inflammation has yet to be studied. In this study, we examined whether D1-like-R antagonist suppresses OVA-induced neutrophilic airway inflammation in OVA TCR-transgenic DO11.10 mice and then elucidated the mechanism of action. DO11.10 mice were nebulized with OVA or PBS, and some mice received D1-like-R antagonist orally before OVA nebulization. D1-like-R antagonist significantly suppressed OVA-induced neutrophilic airway inflammation in DO11.10 mice. It also inhibited the production of IL-17 and infiltration of Th17 cells in the lung. Further, D1-like-R antagonist suppressed the production of IL-23 by lung CD11c(+) APCs. In contrast, D1-like-R antagonist did not increase Foxp3(+) regulatory T cells in the lung. D1-like-R antagonist neither suppressed nonspecific LPS-induced neutrophilic airway inflammation nor OVA-induced eosinophilic airway inflammation. These results indicate that D1-like-R antagonist could suppress Th17-mediated neutrophilic airway inflammation, raising the possibility that antagonizing D1-like-R serves as a promising new strategy for treating neutrophil-dominant severe asthma.

Clinical and radiological features of acute-onset diffuse interstitial lung diseases in patients with rheumatoid arthritis receiving treatment with biological agents: importance of Pneumocystis pneumonia in Japan revealed by a multicenter study

OBJECTIVE

Acute-onset diffuse interstitial lung disease (AoDILD) in patients with rheumatoid arthritis (RA) has been a serious concern, especially for those under treatment with biological agents which may affect the presentation and outcome of AoDILD, including Pneumocystis pneumonia (PCP). Therefore, we conducted a retrospective, multi-center study of AoDILD in RA patients receiving biological agents.

METHODS

Patients who developed AoDILD while receiving biological agents (infliximab, etanercept, adalimumab and tocilizumab) were enrolled in the study. Definite PCP was defined as patients who showed either P. jirovecii organisms in their respiratory samples by microscopic examination, or positive tests for both P. jirovicii DNA-PCR with respiratory samples and an elevated serum 1,3-β-D-glucan level above the cut-off value. Probable PCP was defined as either a positive test for P. jirovicii PCR or an elevated serum β-D-glucan level. Chest HRCT findings were evaluated and scored by two board-certified radiologists.

RESULTS

The final diagnoses for 26 patients examined were definite PCP for 13 patients, probable PCP for 11, and methotrexate-associated pneumonitis in 2 patients. Definite and probable PCP cases were clinically indistinguishable. Generalized, diffuse ground-glass opacity (GGO) is the characteristic HRCT finding in patients with definite or probable PCP, which was different from our previous findings in RA patients, mostly without biologics, showing GGO distributed in a panlobular or multilobular manner. The clinical outcome was favorable by treatment with trimethoprim-sulfamethoxazole and glucocorticoids.

CONCLUSION

The possibility of PCP should be intensively investigated in RA patients developing AoDILD while receiving biological agents.

Intratracheal delivery of hepatocyte growth factor directly attenuates allergic airway inflammation in mice

Hepatocyte growth factor (HGF) has an important role in many biological events such as angiogenesis and cell proliferation, as well as anti-fibrotic and anti-apoptotic effects. In addition, we found that HGF suppresses antigen-induced immune responses in the airway by suppressing dendritic cell functions, using a HGF-producing plasmid vector. In the present study, we examined whether delivery of the HGF protein in the lung attenuates allergic airway inflammation in a mouse model. Generally, HGF is rapidly cleared from organs. So, to achieve the efficient delivery of HGF, we prepared a slow-releasing form by mounting recombinant human (rh) HGF protein in biodegradable gelatin hydrogels. BALB/c mice were immunized and then challenged with ovalbumin (OVA) to induce eosinophilic airway inflammation. Intratracheal delivery of a very small amount of gelatin-coupled rhHGF (0.3 microg) just once before the inhalation of OVA significantly suppressed eosinophilic airway inflammation. In addition, cytokine production in thoracic lymph nodes and the antigen-presenting capacity of lung CD11c+ cells were reduced. In contrast, delivery of 1.0 microg of rhHGF did not exhibit any significantly suppressive effect. These results suggest that the controlled release of rhHGF protein can suppress antigen-induced allergic immune responses in the lung. Therefore, HGF could be a novel therapeutic option for asthma.

Upregulation of lung dendritic cell functions in elastase-induced emphysema

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is now considered a chronic inflammatory disease. Although dendritic cells (DCs) are thought to play a key role in immune responses, studies investigating the role of DCs in COPD are quite limited.

METHODS

Porcine pancreas elastase was intratracheally administered to C57BL/6J mice on day 0. On days 2, 7 and 14, emphysema formation was evaluated by pressure-volume relationships and microscopic findings, including measurement of the mean linear intercept. Lung DCs were isolated on day 2, and their ability to stimulate allogeneic T cells and to produce cytokines was examined.

RESULTS

Pathologic emphysematous change was observed on day 2 and a significant increase in lung volume was observed on day 14. Lung DC function, such as the induction of T-cell proliferation and IL-10 production, was upregulated.

CONCLUSIONS

Upregulation of DC function was observed in elastase-induced emphysema. Further investigation on the contribution to emphysema formation may provide a useful target for future therapy.

Pravastatin attenuates allergic airway inflammation by suppressing antigen sensitisation, interleukin 17 production and antigen presentation in the lung

BACKGROUND

Statins are widely used to treat hyperlipidaemia. Their immunosuppressive effect has recently been confirmed in various immune mediated disease models. However, relatively few studies have been conducted on allergic inflammation, so the precise mechanisms of their actions against allergies have not been fully clarified. On the other hand, the role of interleukin (IL)17 in immune responses has been recently highlighted, but whether statins affect IL17 production has not been well studied. The effect of pravastatin on allergic airway inflammation in a mouse model was examined to elucidate the mechanism of action, focusing on its effect on IL17 production.

METHODS

BALB/c mice were immunised with ovalbumin (OVA) and then challenged with OVA aerosol. Pravastatin was delivered by intraperitoneal injection during either sensitisation or the challenge.

RESULTS

When delivered during systemic sensitisation, pravastatin suppressed OVA induced proliferation and production of Th2 type cytokines such as IL5 in spleen cells ex vivo and in vitro. IL17 production was also suppressed. Furthermore, pavastatin delivered during the inhalation of OVA attenuated eosinophilic airway inflammation, OVA specific IgE production in serum and OVA induced IL17 production in the thoracic lymph node. We also found that pravastatin attenuated the antigen presenting capacity of CD11c(+) cells obtained from the OVA challenged lung.

CONCLUSION

Pravastatin suppresses the systemic sensitisation to allergen with downregulation of IL17 production. It also suppresses an ongoing immune response in the airway partly by suppressing antigen presentation in the lung. Therefore, statins could be a novel therapeutic option for treatment of asthma.