Pneumocystis jiroveci (carinii) pneumonia after infliximab therapy: a review of 84 cases

Pneumocystis jirovecii Pneumonia in HIV-Negative, Non-transplant Patients: Epidemiology, Clinical Manifestations, Diagnosis, Treatment, and Prevention

Purpose of Review

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection that is increasingly seen in HIV-negative patients with immune compromise due to other etiologies. We lack comprehensive clinical recommendations for this population.

Recent Findings

In non-HIV cases, PJP has a mortality rate of up to 50%, which is unacceptable despite the presence of safe and effective prophylaxis and therapy. Steroid use is one of the most common risk factors for disease development. New data suggests that lower doses of the preferred treatment regimen, TMP-SMX, may be equally effective for treatment while limiting side effects. While commonly used, the benefit of corticosteroids for the treatment of PJP has recently been called into question, with a recent multicenter cohort demonstrating no benefit among solid organ transplant recipients.

Summary

A high suspicion of PJP in individuals with pneumonia during immunosuppressant use is crucial. Therapeutic options are evolving to decrease potential side effects while maintaining efficacy in this highly morbid disease.

Risk Factors of Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease: A Nationwide Population-Based Study

Background/Aims

: Pneumocystis jirovecii pneumonia (PJP) is a rare but potentially fatal infection. This study was conducted to investigate the risk factors for PJP in inflammatory bowel disease (IBD) patients.

Methods

: This nationwide, population-based study was conducted in Korea using claims data. Cases of PJP were identified in patients diagnosed with ulcerative colitis (UC) or Crohn's disease (CD) between 2010 and 2017, and the clinical data of each patient was analyzed. Dual and triple therapy was defined as the simultaneous prescription of two or three of the following drugs: steroids, calcineurin inhibitors, immunomodulators, and biologics.

Results

: During the mean follow-up period (4.6±2.3 years), 84 cases of PJP were identified in 39,462 IBD patients (31 CD and 53 UC). For CD patients, only age at diagnosis >40 years (hazard ratio [HR], 6.12; 95% confidence interval [CI], 1.58 to 23.80) was significantly associated with the risk of PJP, whereas in UC patients, diagnoses of diabetes (HR, 2.51; 95% CI, 1.19 to 5.31) and chronic obstructive pulmonary disease (HR, 3.41; 95% CI, 1.78 to 6.52) showed significant associations with PJP risk. Triple therapy increased PJP risk in both UC (HR, 3.90; 95% CI, 1.54 to 9.88) and CD patients (HR, 5.69; 95% CI, 2.32 to 14.48). However, dual therapy increased PJP risk only in UC patients (HR, 2.53; 95% CI, 1.36 to 4.70). Additionally, 23 patients (27%) received intensive care treatment, and 10 (12%) died within 30 days.

Conclusions

: PJP risk factors differ in CD and UC patients. Considering the potential fatality of PJP, prophylaxis should be considered for at-risk IBD patients.

Incidence of invasive fungal diseases in inflammatory bowel disease patients: A nationwide study in South Korea

BACKGROUND

Limited reports exist regarding invasive fungal diseases (IFDs) in inflammatory bowel disease (IBD) patients.

OBJECTIVES

This study aims to investigate the incidence and risk factors of IFDs, specifically invasive candidiasis, aspergillosis and pneumocystosis, in IBD patients in South Korea using nationwide data.

PATIENTS/METHODS

A population-based retrospective cohort of 42,913 IBD patients between January 2010 and December 2018 was evaluated using the Health Insurance Review and Assessment database. The primary outcome was the incidence of IFDs, including invasive candidiasis, aspergillosis and pneumocystosis, while the secondary outcome involved analysing the risk factors associated with each specific infection.

RESULTS

The study included a total of 42,913 IBD patients, with 29,909 (69.7%) diagnosed with ulcerative colitis (UC) and 13,004 (30.3%) diagnosed with Crohn's disease (CD). IFDs occurred in 166 IBD patients (0.4%), with 93 cases in UC patients and 73 cases in CD patients. The incidence rates of invasive candidiasis, aspergillosis and pneumocystosis in IBD patients were 0.71 per 1000 person-years (PYs), 0.15 per 1000 PYs and 0.12 per 1000 PYs, respectively. The cumulative incidence of invasive candidiasis (adjusted p-value <.001) and Pneumocystosis (adjusted p-value = .012) was found to be higher in CD patients than in UC patients. Each IFD had different risk factors, including IBD subtypes, age at diagnosis, anti-tumour necrotic factor agents or the Charlson comorbidity index.

CONCLUSION

Based on nationwide data in South Korea, this study shows that IFDs occur consistently in patients with IBD, albeit with a low frequency.

Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

How to diagnose and treat a non-HIV patient with Pneumocystis jirovecii pneumonia (PCP)?

BACKGROUND

Pneumocystis jirovecii Pneumonia (PCP) incidence is increasing in non-HIV infected patients. In contrast to PCP in patients infected with HIV, diagnosis is often delayed, and illness is associated with an increased mortality.

OBJECTIVE

To provide a comprehensive review of clinical presentation, risk factors, diagnostic strategies, and treatment options of PCP in non-HIV-infected patients.

SOURCES

Web-based literature review on PCP for trials, meta-analyses and systematic reviews using PubMed. Restriction to English language was applied.

CONTENT

Common underlying conditions in non-HIV-infected patients with PCP are haematological malignancies, autoimmune and inflammatory diseases, solid organ or haematopoietic stem cell transplant and prior exposure to corticosteroids. New risk groups include patients receiving monoclonal antibodies and immunomodulating therapies. Non-HIV-infected patients with PCP present with rapid onset and progression of pneumonia, increased duration of hospitalization and a significantly higher mortality rate than patients infected with HIV. PCP is diagnosed by a combination of clinical symptoms, radiological and mycological features. Immunofluorescence microscopy from bronchoalveolar lavage (BAL) or PCR testing CT imaging and evaluation of the clinical presentation are required. The established treatment regime consists of trimethoprim and sulfamethoxazole.

IMPLICATIONS

While the number of patients immunosuppressed for other causes than HIV is increasing, a simultaneous rise in PCP incidence is observed. In the group of non-HIV-infected patients, a rapid onset of symptoms, a more complex course, and a higher mortality rate are recorded. Therefore, time to diagnosis must be as short as possible to initiate effective therapy promptly. This review aims to raise awareness of PCP in an increasingly affected at-risk group and provide clinicians with a practical guide for efficient diagnosis and targeted therapy. Furthermore, it intends to display current inadequacies in research on the topic of PCP.

Efficacy of sulfasalazine for the prevention of Pneumocystis pneumonia in patients with rheumatoid arthritis: A multicentric self-controlled case series study

INTRODUCTION

Pneumocystis pneumonia (PCP) is an opportunistic lung infection and has been reported among patients with rheumatoid arthritis (RA). An animal study revealed that sulfasalazine enhances Pneumocystis clearance from the lung by accelerating macrophage activity.

METHODS

The self-controlled case series (SCCS) method was used to investigate the association between sulfasalazine use and PCP development in patients with RA without the effect of time-invariant, interpatient confounders. PCP episodes which developed in patients with RA at five hospitals between 2003 and 2019 were identified. PCP was defined by the following criteria: 1) detection of Pneumocystis jirovecii in respiratory specimens by polymerase chain reaction; 2) clinical symptoms (pyrexia, dry cough, dyspnea or hypoxia); 3) diffuse interstitial infiltrate on chest imaging; and 4) absence of PCP prophylaxis. The PCP incidence rate ratio (IRR) was compared between periods with and without sulfasalazine use by conditional Poisson regression.

RESULTS

Fifty episodes of PCP were identified in 49 patients. Thirty patients received sulfasalazine at some point during their observation. While 49 episodes of PCP developed in 170.3 person-years without sulfasalazine use, only one episode of PCP developed in 103.7 person-years with sulfasalazine use. Sulfasalazine use was associated with a decreased PCP risk (adjusted IRR <0.01; 95% confidence interval <0.01-0.03) after adjusting for age and glucocorticoid, methotrexate, and tumor necrosis factor inhibitor administration.

CONCLUSION

Our study demonstrated a preventive effect of sulfasalazine against PCP in patients with RA.

The Pathogenesis and Diagnosis of Pneumocystis jiroveci Pneumonia

Pneumocystis jiroveci remains an important fungal pathogen in immunocompromised hosts. The environmental reservoir remains unknown. Pneumonia (PJP) results from airborne transmission, including in nosocomial clusters, or with reactivation after an inadequately treated infection. Pneumocystis pneumonia most often occurs within 6 months of organ transplantation, with intensified or prolonged immunosuppression, notably with corticosteroids and following cytomegalovirus (CMV) infections. Infection may be recognized during recovery from neutropenia and lymphopenia. Invasive procedures may be required for early diagnosis and therapy. Despite being a well-established entity, aspects of the pathogenesis of PJP remain poorly understood. The goal of this review is to summarize the data on the pathogenesis of PJP, review the strengths and weaknesses of the pertinent diagnostic modalities, and discuss areas for future research.

Prophylaxis for Pneumocystis jirovecii pneumonia in patients with inflammatory bowel disease: A systematic review

Patients with inflammatory bowel disease (IBD) are at increased risk of developing Pneumocystis jirovecii pneumonia (PJP) than the general population. Many medications utilized for the treatment of IBD affect the immune system, potentially further increasing the risk of PJP. Recommendations for prophylaxis against PJP in this patient population are based upon limited evidence, and risk factors for PJP development are not well-agreed upon. The purpose of this systematic review was to consolidate and evaluate the evidence for PJP prophylaxis in patients with IBD. An electronic literature search was performed, and 29 studies were included in the review, of which 24 were case reports or case series. Combined data from five cohort studies showed an absolute risk of developing PJP to be 0.07%. The majority of patients who developed PJP were receiving corticosteroids at the time of diagnosis (76%). The number of concomitant immunosuppressants received at time of PJP diagnosis varied from one to four. All studies reporting treatment of PJP utilized sulfamethoxazole-trimethoprim. Of the 27 studies reporting mortality data, 19% of patients died. Given the lack of conclusive data regarding risk factors for PJP development and the overall low incidence of PJP in patients with IBD, it is recommended to assess the patient's risk on a case-by-case basis to determine whether PJP prophylaxis is warranted.

Pneumocystis jirovecii pneumonia in patients with inflammatory bowel disease - A case series

BACKGROUND AND AIM

Pneumocystis jirovecii pneumonia (PJP) is a very rare, potentially life-threatening pulmonary fungal infection that occurs in immunocompromised individuals including patients with inflammatory bowel disease (IBD). Our aim was to describe immunosuppressive treatment exposure as well as the outcome in IBD patients with PJP.

METHODS

PJP cases were retrospectively collected through the COllaborative Network For Exceptionally Rare case reports of the European Crohn's and Colitis Organization. Clinical data were provided through a case report form.

RESULTS

18 PJP episodes were reported in 17 IBD patients (10 ulcerative colitis and 7 Crohn's disease). The median age on PJP diagnosis was 55 years (IQR, 40-68 years). Two PJP (11.1%) occurred in patients on triple immunosuppression, 10 patients (55.6%) had double immunosuppressive treatment, 4 patients (22.2%) had monotherapy and 2 PJP occurred in absence of immunosuppressive treatment (one in a human immunodeficiency virus patient and one in a patient with a history of autologous stem cell transplantation). Immunosuppressive therapies included steroids (n=12), thiopurines (n=10), infliximab (n=4), ciclosporin (n=2), methotrexate (n=1) and tacrolimus (n=1). None of the patients diagnosed with PJP had received prophylaxis. All patients were treated by trimethoprim/sulfamethoxazole or atovaquone and an ICU stay was required in 7 cases. Two patients (aged 71 and 32 years) died, and one patient had a recurrent episode 16 months after initial treatment. Evolution was favourable for the others.

CONCLUSION

This case series reporting potentially fatal PJP highlights the need for adjusted prophylactic therapy in patients with IBD on immunosuppressive therapy.

Outcomes and Risk Factors for Mortality in Pneumocystis Pneumonia Patients with Rheumatoid Arthritis: A Multicenter Retrospective Cohort Study

OBJECTIVE

To evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP).

METHODS

: We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined.

RESULTS

Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (RA-ILD; odds ratio [OR] 6.18, 95% confidence interval [CI] 1.17-32.63) and delayed PCP treatment with anti-Pneumocystis drugs (OR 15.29, 95% CI 1.50-156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years).

CONCLUSION

To avoid a treatment delay, RA patients should be followed-up for signs and symptoms of PCP development, especially those with RA-ILD.

Pathophysiological Concepts and Management of Pulmonary Manifestation of Pediatric Inflammatory Bowel Disease

Pulmonary manifestation (PM) of inflammatory bowel disease (IBD) in children is a rare condition. The exact pathogenesis is still unclear, but several explanatory concepts were postulated and several case reports in children were published. We performed a systematic Medline search between April 1976 and April 2022. Different pathophysiological concepts were identified, including the shared embryological origin, "miss-homing" of intestinal based neutrophils and T lymphocytes, inflammatory triggering via certain molecules (tripeptide proline-glycine-proline, interleukin 25), genetic factors and alterations in the microbiome. Most pediatric IBD patients with PM are asymptomatic, but can show alterations in pulmonary function tests and breathing tests. In children, the pulmonary parenchyma is more affected than the airways, leading histologically mainly to organizing pneumonia. Medication-associated lung injury has to be considered in pulmonary symptomatic pediatric IBD patients treated with certain agents (i.e., mesalamine, sulfasalazine or infliximab). Furthermore, the risk of pulmonary embolism is generally increased in pediatric IBD patients. The initial treatment of PM is based on corticosteroids, either inhaled for the larger airways or systemic for smaller airways and parenchymal disease. In summary, this review article summarizes the current knowledge about PM in pediatric IBD patients, focusing on pathophysiological and clinical aspects.

A Rare Case of Ulcerative Colitis with Severe Pneumocystis jirovecii Pneumonia and Cytomegalovirus Colitis: A Case Report and Literature Review

Pneumocystis jirovecii pneumonia (PJP) and cytomegalovirus (CMV) colitis are opportunistic infections that occur during immunosuppressive treatments for ulcerative colitis (UC). The prognosis of PJP and CMV colitis is very poor. We herein report a rare case of a 74-year-old UC patient with PJP and CMV colitis that was successfully treated with intensive therapy. PJP progresses rapidly, so the timing and choice of treatment are critical. Furthermore, a literature review of similar cases suggested that prophylactic therapy for opportunistic infections might be important, especially in the elderly. This case will serve as a reference for successful treatment in future cases.

COVID-19-associated opportunistic infections: a snapshot on the current reports

Treatment of the novel Coronavirus Disease 2019 (COVID-19) remains a complicated challenge, especially among patients with severe disease. In recent studies, immunosuppressive therapy has shown promising results for control of the cytokine storm syndrome (CSS) in severe cases of COVID-19. However, it is well documented that immunosuppressive agents (e.g., corticosteroids and cytokine blockers) increase the risk of opportunistic infections. On the other hand, several opportunistic infections were reported in COVID-19 patients, including Aspergillus spp., Candida spp., Cryptococcus neoformans, Pneumocystis jiroveci (carinii), mucormycosis, Cytomegalovirus (CMV), Herpes simplex virus (HSV), Strongyloides stercoralis, Mycobacterium tuberculosis, and Toxoplasma gondii. This review is a snapshot about the main opportunistic infections that reported among COVID-19 patients. As such, we summarized information about the main immunosuppressive agents that were used in recent clinical trials for COVID-19 patients and the risk of opportunistic infections following these treatments. We also discussed about the main challenges regarding diagnosis and treatment of COVID-19-associated opportunistic infections (CAOIs).

Immune Response in Pneumocystis Infections According to the Host Immune System Status

The host immune response is critical in Pneumocystis pneumonia (PCP). Immunocompetent hosts can eliminate the fungus without symptoms, while immunodeficient hosts develop PCP with an unsuitable excessive inflammatory response leading to lung damage. From studies based on rodent models or clinical studies, this review aimed to better understand the pathophysiology of Pneumocystis infection by analysing the role of immune cells, mostly lymphocytes, according to the immune status of the infected host. Hence, this review first describes the immune physiological response in infected immunocompetent hosts that are able to eliminate the fungus. The objective of the second part is to identify the immune elements required for the control of the fungus, focusing on specific immune deficiencies. Finally, the third part concentrates on the effect of the different immune elements in immunocompromised subjects during PCP, to better understand which cells are detrimental, and which, on the contrary, are beneficial once the disease has started. This work highlights that the immune response associated with a favourable outcome of the infection may differ according to the immune status of the host. In the case of immunocompetency, a close communication between B cells and TCD4 within tertiary lymphocyte structures appears critical to activate M2 macrophages without much inflammation. Conversely, in the case of immunodeficiency, a pro-inflammatory response including Th1 CD4, cytotoxic CD8, NK cells, and IFNγ release seems beneficial for M1 macrophage activation, despite the impact of inflammation on lung tissue.

Crohn's Disease is Associated with Longer In-Hospital Lengths of Stay and Higher Rates of Complications and Costs after Primary Total Hip Arthroplasty

BACKGROUND

As the incidence and prevalence of Crohn's disease continues to change worldwide, rates within North America have been increasing. The objective of this study was to evaluate whether patients who have Crohn's disease undergoing primary total hip arthroplasties have worse outcomes compared with matched cohorts. Specifically, we evaluated 1) medical complications, 2) in-hospital lengths of stay (LOS), and 3) costs of care.

METHODS

Two cohorts of patients who underwent primary total hip arthroplasties from January 1, 2005 to March 31, 2014 were identified from the Medicare claims of the PearlDiver platform. Cohorts were matched by age, sex, and following comorbidities-anemia, diabetes, hyperlipidemia, hypertension, malnutrition, pulmonary disease, and renal failure, yielding 55,361 patients within the study (n = 9229) and matching cohorts (n = 46,132). Outcomes assessed included 90-day medical complications, in-hospital LOS, and costs of care. A P-value less than .005 was considered statistically significant.

RESULTS

Patients with Crohn's disease were found to have significantly higher incidences and odds ratios of 90-day medical complications (30.2 vs 13.8; odds ratios: 2.2, P < .0001). They were also found to have significantly longer LOS (3.8- vs 3.6-days, P < .0001) and higher day of surgery ($12,662.00 vs 12,271.15, P < .0001) and 90-day episode costs ($16,933.18 vs $15,670.32, P < .0001).

CONCLUSION

Crohn's disease is associated with higher rates of medical complications, longer in-hospital LOS, and increased costs of care. This study may aid physicians to perform appropriate risk adjustment for adverse outcomes and to educate these patients about potential postoperative complications in these patients.

Inflammatory bowel disease and the lung in paediatric patients

The prevalence of inflammatory bowel disease (IBD) has increased over the past 20 years. Pulmonary involvement in paediatric IBD is rare but may be missed since the spectrum of symptoms is broad and mimics other diseases. The most important differential diagnoses of pulmonary manifestations of IBD are infections and therapy-related side-effects. There is no gold standard to diagnose respiratory manifestations in children with IBD. Diagnostic tests should be chosen according to history and clinical presentation. Treatment of respiratory manifestations of IBD includes inhaled or oral corticosteroids and initiation or step-up of immunomodulatory IBD therapies.

Pulmonary involvement in paediatric IBD is rare but may be underdiagnosed. The spectrum of symptoms is broad and mimics other diseases. The differentiation between IBD-related and drug-induced pulmonary manifestation can be challenging.https://bit.ly/3uZBvpA

Critical Care of Patients With Cardiopulmonary Complications of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease defined by the presence of aberrant granulomas affecting various organs. Due to its multisystem involvement, care of patients with established sarcoidosis becomes challenging, especially in the intensive care setting. While the lungs are typically involved, extrapulmonary manifestations also occur either concurrently or exclusively within a significant proportion of patients, complicating diagnostic and management decisions. The scope of this review is to focus on what considerations are necessary in the evaluation and management of patients with known sarcoidosis and their associated complications within a cardiopulmonary and critical care perspective.

Pharmacovigilance of Biopharmaceuticals in Rheumatic Diseases, Adverse Events, Evolution, and Perspective: An Overview

Since we have gained an understanding of the immunological pathophysiology of rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus, treatment based on biological drugs has become a fundamental axis. These therapies are oriented towards the regulation of cytokines such as tumour necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1, and the modulation of cell-mediated immunity (B cells and T cells) by anti CD20 or anti CTAL-4 agents, and can increase the risk of associated infections or adverse events (AE). In this context, the entry of biotherapeutics represented a challenge for pharmacovigilance, risk management and approval by the main global regulatory agencies regarding biosimilars, where efficacy and safety are based on comparability exercises without being an exact copy in terms of molecular structure. The objective of this review is divided into three fundamental aspects: (i) to illustrate the evolution and focus of pharmacovigilance at the biopharmaceutical level, (ii) to describe the different approved recommendations of biopharmaceuticals (biological and biosimilars) and their use in rheumatic diseases (RDs) such as rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE) and other less frequent RD like cryopyrin-associated autoinflammatory syndromes (CAPS), and (iii) to identify the main AE reported in the post-marketing phase of RD biopharmaceuticals.

Fungal Infections Potentiated by Biologics

Biologic therapies including monoclonal antibodies, tyrosine kinase inhibitors, and other agents represent a notable expansion in the pharmacotherapy armamentarium in treatment of a variety of diseases. Many of these therapies possess direct or indirect immunosuppressive and immunomodulatory effects, which have been associated with bacterial, viral, and fungal opportunistic infections. Careful screening of baseline risk factors before initiation, targeted preventive measures, and vigilant monitoring while on active biologic therapy mitigate these risks as use of biologics becomes more commonplace. This review compiles reported evidence of fungal infections associated with these agents with a focus on the tumor necrosis factor-α inhibitor class.

Risks and benefits of corticosteroids in arthritic diseases in the clinic

Glucocorticoids (GCs) constitute a first line treatment for many autoimmune and inflammatory diseases. Due to their potent anti-inflammatory and immunosuppressive actions, GCs are added frequently to disease modifying antirheumatic drugs (DMARDs) in various arthritic diseases, such as rheumatoid arthritis. However, their prolonged administration or administration at high doses is associated with adverse effects that may be (quality of) life-threatening, including osteoporosis, metabolic, gastrointestinal and cardiovascular side effects. In this review, we summarize the clinical and pharmacological effects of GCs in different arthritic diseases, while documenting the current research efforts towards the identification of novel and more efficient GCs with reduced side effects.

Pneumocystis jirovecii pneumonia prophylaxis in immunocompromised patients with systemic autoimmune diseases

Pneumocystis jirovecii (P. jirovecii) causes a potentially fatal pneumonia in immunocompromised individuals (Pneumocystis pneumonia or PcP), particularly in HIV-infected patients and those treated with immunosuppressive drugs, such as transplant patients and those with systemic autoimmune diseases. P. jirovecii colonization can be found in almost a third of patients with systemic autoimmune diseases. Although the incidence of PcP in such patients is usually low, mortality is quite high, ranging between 30% and 50% in the majority of autoimmune diseases. PcP development is almost always observed in patients not receiving prophylaxis for the infection. Despite the above, there are no clinical guidelines established for PcP prophylaxis in patients with autoimmune diseases treated with glucocorticoids, cytotoxic drugs, or more recently, biological agents. The objective of this review is to analyze the available data on the incidence of PcP and the effect of PcP prophylaxis in patients with autoimmune diseases that may be useful in clinical practice.

Review article: managing the adverse events caused by anti-TNF therapy in inflammatory bowel disease

BACKGROUND

Biological therapy is currently widely used to treat IBD. Infliximab, adalimumab and golimumab are currently licensed anti-TNF therapies. Biosimilar anti-TNF monoclonal antibodies are increasingly used. Anti-TNF therapies are widely used and their adverse effects are well characterised, and may cause significant morbidity and mortality in a small proportion of exposed patients. Gastroenterologists need to understand the mechanisms for these effects, recognise these swiftly and manage such events appropriately.

AIM

To cover the range of potential adverse reactions as a result of biologic therapy and specifically management of these events.

METHODS

A Medline and Pubmed search was undertaken. Search terms included were "anti-TNF," "infliximab" or "adalimumab" or "golimumab" combined with the keywords "ulcerative colitis" or "Crohn's disease" or "inflammatory bowel disease" and then narrowed to articles containing the keywords "complications," "side effects" or "adverse events" or "safety profile." International guidelines were also reviewed where relevant.

RESULTS

Adverse events discussed in this review include infusion reactions, blood disorders and infections (including bacterial, viral, fungal and opportunistic infections) as well as autoimmune, dermatological disorders, cardiac and neurological conditions. Malignancies including solid organ, haematological and those linked to viral disease are discussed.

CONCLUSIONS

Anti-TNF therapy has wide-ranging effects on the immune system resulting in a spectrum of potential adverse events in a small proportion of patients. Research advances are improving the understanding, recognition and management of these adverse events.

Risk Factors for Mortality in Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease

Background

Pneumocystis jirovecii pneumonia (PJP) is highly fatal once infection is established. In this study, we investigated the risk of PJP mortality in patients with inflammatory bowel disease (IBD).

Methods

We conducted a retrospective observational study of case data from IBD patients who developed PJP, compiled from 17 collaborating institutions. Parameters such as age, sex, medications used, and blood test results were analyzed to identify risk factors for mortality.

Results

The mortality rate among the 28 IBD patients who developed PJP was 17.9%. A low serum albumin level at the start of IBD treatment was identified as a risk factor for mortality and showed the following association with probability of death (P): P = 1/[1 + exp(-5.5 + 2.4 × Alb). The probability of death exceeded 0.5 when serum albumin was 2.2 g/dL or lower.

Conclusion

Patients with IBD who develop PJP have a high mortality rate and often cannot continue treatment with medication alone. Therefore, it is necessary to pay attention to albumin levels at the start of immunosuppressive therapy when creating a treatment plan.

Therapy and Management of Pneumocystis jirovecii Infection

The rates of Pneumocystis pneumonia (PcP) are increasing in the HIV-negative susceptible population. Guidance for the prophylaxis and treatment of PcP in HIV, haematology, and solid-organ transplant (SOT) recipients is available, although for many other populations (e.g., auto-immune disorders) there remains an urgent need for recommendations. The main drug for both prophylaxis and treatment of PcP is trimethoprim/sulfamethoxazole, but resistance to this therapy is emerging, placing further emphasis on the need to make a mycological diagnosis using molecular based methods. Outbreaks in SOT recipients, particularly renal transplants, are increasingly described, and likely caused by human-to-human spread, highlighting the need for efficient infection control policies and sensitive diagnostic assays. Widespread prophylaxis is the best measure to gain control of outbreak situations. This review will summarize diagnostic options, cover prophylactic and therapeutic management in the main at risk populations, while also covering aspects of managing resistant disease, outbreak situations, and paediatric PcP.

Risk of infection associated with anti-TNF-α therapy

INTRODUCTION

The advent, more than two decades ago, of monoclonal antibodies and soluble receptors targeting tumor necrosis factor (TNF)-α has revolutionized the therapeutic approach to otherwise difficult-to-treat autoimmune and inflammatory diseases. However, due to the pleiotropic functions played by this pro-inflammatory cytokine (with particular relevance in granuloma maintenance), TNF-α blockade may increase the incidence of serious infections. Areas covered: The present review summarizes the biological rationale supporting the impact of anti-TNF-α therapy on the host's susceptibility to infection. The structure, mode of action, and indications of available agents are reviewed, as well as the clinical evidence coming from clinical trials and observational registries. We discuss the impact of patient- and disease-related factors influencing the occurrence of infection. Finally, strategies for risk minimization are also covered, with particular attention to recommendations for screening of latent tuberculosis infection and management of chronic hepatitis B infection. Expert commentary: Methodological limitations (confounding by indication bias, patient dropout, or switching therapies) should be considered when interpreting observational data. Clinicians must individualize the infection risk assessment not only on the basis of the specific anti-TNF-α agent used or the expected duration of therapy, but also by taking into account the baseline susceptibility of a given patient.

Management of Paediatric Ulcerative Colitis, Part 2: Acute Severe Colitis-An Evidence-based Consensus Guideline From the European Crohn's and Colitis Organization and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND AND AIM

Acute severe colitis (ASC) is one of the few emergencies in pediatric gastroenterology. Tight monitoring and timely medical and surgical interventions may improve outcomes and minimize morbidity and mortality. We aimed to standardize daily treatment of ASC in children through detailed recommendations and practice points which are based on a systematic review of the literature and consensus of experts.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Fifteen predefined questions were addressed by working subgroups. An iterative consensus process, including 2 face-to-face meetings, was followed by voting of the national representatives of ECCO and all members of the Paediatric Inflammatory Bowel Disease (IBD) Porto group of ESPGHAN (43 voting experts).

RESULTS

A total of 24 recommendations and 43 practice points were endorsed with a consensus rate of at least 91% regarding diagnosis, monitoring, and management of ASC in children. A summary flowchart is presented based on daily scoring of the Paediatric Ulcerative Colitis Activity Index. Several topics have been altered since the previous 2011 guidelines and from those published in adults.

DISCUSSION

These guidelines standardize the management of ASC in children in an attempt to optimize outcomes of this intensive clinical scenario.

Pneumocystis jiroveci pneumonia in a patient taking Benepali for rheumatoid arthritis

We present a case of a 57-year-old woman who contracted Pneumocystis jiroveci pneumonia while on Benepali, the biosimilar version of etanercept for rheumatoid arthritis. She had seropositive erosive disease. She was admitted to clinic with a 2-week history of dyspnoea, dry cough and fever. Her initial examination showed her to be hypoxic on air with saturations of 77% and left basal crackles. Her admission chest X-ray showed fine reticular shadowing, with an initial suspicion of pulmonary fibrosis. She was empirically treated for community-acquired pneumonia but continued to deteriorate with a worsening type 1 respiratory failure. She was intubated and ventilated on intensive care. The suspicion was raised of P. jiroveci pneumonia given her immunosuppression, hypoxic presentation and chest X-ray changes. This was confirmed on sputum PCR. She was treated with a 3-week course of steroids and co-trimoxazole. She was discharged home after a 2-week admission.

Fungal infections in patients with inflammatory bowel disease: A systematic review

BACKGROUND

Despite reports of fungal infections in patients with inflammatory bowel disease (IBD), their clinical and microbiological characteristics remain unknown.

OBJECTIVES

The aim of this systematic review was to examine all available evidence regarding fungal infections in patients with IBD.

METHODS

Systematic search of PubMed (through 27 May 2017) for studies providing data on clinical, microbiological, treatment and outcome data of fungal infections in patients with IBD. The primary study outcome was to record the most common fungal species in patients with IBD. Secondary outcomes were classified into 3 categories: (i) characteristics of fungal infections; (ii) data on IBD and (iii) treatment and outcomes of fungal infections in patients with IBD.

RESULTS

Fourteen studies with data on 1524 patients were included in final analysis. The most common fungal infections in patients with IBD were caused by Candida species (903 infections); the most commonly reported site of Candida infection was the gastrointestinal tract. Available evidence shows that most fungal infections occur within 12 months of IBD treatment and within 6 months when anti-TNFa agents are used.

CONCLUSIONS

This systematic review thoroughly describes fungal infections in patients with IBD and provides important information for the early detection and management of these infections.

Pneumocystis PCR: It Is Time to Make PCR the Test of Choice

Background

The testing strategy for Pneumocystis at the Cleveland Clinic changed from toluidine blue staining to polymerase chain reaction (PCR). We studied the differences in positivity rates for these assays and compared each with the detection of Pneumocystis in companion specimens by cytology and surgical pathology.

Methods

We reviewed the results of all Pneumocystis test orders 1 year before and 1 year after the implementation of a Pneumocystis-specific PCR. We also reviewed the corresponding cytology and surgical pathology results, if performed. Finally, we reviewed the medical records of patients with rare Pneumocystis detected by PCR in an effort to differentiate colonization vs true disease.

Results

Toluidine blue staining and surgical pathology had similar sensitivities and negative predictive values, both of which were superior to cytology. There was a >4-fold increase in the annual detection of Pneumocystis by PCR compared with toluidine blue staining (toluidine blue staining: 11/1583 [0.69%] vs PCR: 44/1457 [3.0%]; chi-square P < .001). PCR detected 1 more case than surgical pathology and was far more sensitive than cytology. Chart review demonstrated that the vast majority of patients with rare Pneumocystis detected were immunosuppressed, had radiologic findings supportive of this infection, had no other pathogens detected, and were treated for pneumocystosis by the clinical team.

Conclusion

PCR was the most sensitive method for the detection of Pneumocystis and should be considered the diagnostic test of choice. Correlation with clinical and radiologic findings affords discrimination of early true disease from the far rarer instances of colonization.

Low Risk of Pneumonia From Pneumocystis jirovecii Infection in Patients With Inflammatory Bowel Disease Receiving Immune Suppression

BACKGROUND & AIMS

Use of immunosuppressants and inflammatory bowel disease (IBD) may increase the risk of pneumonia caused by Pneumocystis jirovecii (PJP). We assessed the risk of PJP in a population-based cohort of patients with IBD treated with corticosteroids, immune-suppressive medications, and biologics.

METHODS

We performed a population-based cohort study of residents of Olmsted County, Minnesota, diagnosed with Crohn's disease (n = 427) or ulcerative colitis (n = 510) from 1970 through 2011. Records of patients were reviewed to identify all episodes of immunosuppressive therapies and concomitant PJP prophylaxis through February 2016. We reviewed charts to identify cases of PJP, cross-referenced with the Rochester Epidemiology Project database (using diagnostic codes for PJP) and the Mayo Clinic and Olmsted Medical Center databases. The primary outcome was risk of PJP associated with the use of corticosteroids, immune-suppressive medications, and biologics by patients with IBD.

RESULTS

Our analysis included 937 patients and 6066 patient-years of follow-up evaluation (median, 14.8 y per patient). Medications used included corticosteroids (520 patients; 55.5%; 555.4 patient-years of exposure), immunosuppressants (304 patients; 32.4%; 1555.7 patient-years of exposure), and biologics (193 patients; 20.5%; 670 patient-years of exposure). Double therapy (corticosteroids and either immunosuppressants and biologics) was used by 236 patients (25.2%), with 173 patient-years of exposure. Triple therapy (corticosteroids, immunosuppressants, and biologics) was used by 70 patients (7.5%) with 18.9 patient-years of exposure. There were 3 cases of PJP, conferring a risk of 0.2 (95% CI, 0.01-1.0) to corticosteroids, 0.1 (95% CI, 0.02-0.5) cases per 100 patient-years of exposure to immunosuppressants, 0.3 (95% CI, 0.04-1.1) cases per 100 patient-years of exposure to biologics, 0.6 (95% CI, 0.01-3.2) cases per 100 patient-years of exposure to double therapy, and 0 (95% CI, 0.0-19.5) cases per 100 patient-years of exposure to triple therapy. Primary prophylaxis for PJP was prescribed to 37 patients, for a total of 24.9 patient-years of exposure.

CONCLUSIONS

In a population-based cohort of patients with IBD treated with corticosteroids, immunosuppressants, and biologics, there were only 3 cases of PJP, despite the uncommon use of PJP prophylaxis. Routine administration of PJP prophylaxis in these patients may not be warranted, although it should be considered for high-risk groups, such as patients receiving triple therapy.

Cytomegalovirus, inflammatory bowel disease, and anti-TNFα

BACKGROUND AND PURPOSE

Anti-TNFα agents emerged in inflammatory bowel disease (IBD) as an effective option in situations that, otherwise, would be refractory to medical therapy. Cytomegalovirus infection may present with a high spectrum of manifestations and lead to high morbidity and mortality. However, its clinical significance in IBD course remains unknown and data on its association with anti-TNFα are limited.

AIMS

This study aims to evaluate cytomegalovirus (CMV) infection/disease in patients with IBD treated with anti-TNFα; if possible, possible risk factors associated with CMV infection/disease in IBD patients under anti-TNFα as well as the influence of CMV infection/disease in IBD course would be determined.

METHODS

During three consecutive years, all IBD patients starting infliximab in our department were included. Cytomegalovirus status before anti-TNFα was evaluated. Data regarding IBD, therapeutic and IBD course after infliximab, were recorded. CMV analysis was performed with polymerase chain reaction (PCR)-cytomegalovirus in peripheral blood and colonoscopy with biopsies (histopathology/immunohistochemistry).

RESULTS

We included 29 patients: female-83%; Crohn's disease-51.8%, ulcerative colitis-44.8%, non-classified colitis-3.4%; 23 cytomegalovirus seropositive. Median follow-up: 19 months (3-36). During follow-up, 14 patients were under combination therapy with azathioprine and 5 did at least 1 cycle of corticosteroids. Twenty-one patients responded to infliximab. We registered 8 exacerbations of IBD. Four patients discontinued infliximab: none had CMV infection. We documented 1 case of intestinal cytomegalovirus infection-detected in biopsies performed per protocol in an asymptomatic UC patient, who responded to valganciclovir without infliximab discontinuation.

CONCLUSIONS

Infliximab, with/without immunosuppression, does not confer an increased risk of (re)activation of cytomegalovirus. Cytomegalovirus was not responsible neither for significant morbidity nor mortality in IBD.

Special situations in inflammatory bowel disease: First Latin American consensus of the Pan American Crohn's and Colitis Organisation (PANCCO) (Second part)

This is the first Latin American Consensus of the Pan American Crohn's and Colitis Organisation (PANCCO) regarding special situations in patients with inflammatory bowel disease (IBD). The aim of this consensus is to raise awareness in the medical community in all Latin American countries with respect to pregnancy, vaccinations, infections, neoplasms, including colorectal cancer, and pediatric issues in patients with IBD.

Pneumocystis jirovecii Pneumonia in Pediatric Inflammatory Bowel Disease: A Case Report and Literature Review

Immunosuppressive therapy is a known risk factor for opportunistic infections. We report the first case of severe Pneumocystis jirovecii infection requiring intensive care in a pediatric patient with inflammatory bowel disease (IBD). The literature was reviewed and there were 92 reported cases of Pneumocystis pneumonia (PCP) in patients with IBD. Most sources were case reports and there was likely reporting bias toward patients receiving immunomodulators, anti-tumor necrosis factor (anti-TNF) therapy, and those who died. Overall, 56% of patients were males and 58% had Crohn's disease. The median age was 45 years (interquartile range 30-68, range 8-78) and 86% of patients were lymphopenic. The case-fatality rate was 23%. Corticosteroids were used as IBD treatment in 88% of patients who subsequently developed PCP, 42% received thiopurines, 44% used anti-TNF therapy, and 15% received either cyclosporine or tacrolimus. Rates of mono, dual, triple, and quadruple immunosuppression therapy were 35, 35, 29, and 2%, respectively. This report highlights the importance of considering PCP in immunosuppressed lymphopenic pediatric IBD patients who present with unusual symptoms. Moreover, it should give gastroenterologists the impetus to limit immunosuppressive therapy to its minimal effective dose and consider options such as exclusive enteral nutrition wherever possible. Although there is no place for global PCP prophylaxis in IBD given the low incidence, in an era when there is increasing use of biologic agents with combination immunosuppressive therapy, the risk-benefit profile of PCP chemoprophylaxis should be revisited in selected cohorts such as patients on triple immunosuppression with corticosteroids, thiopurines, and a biological agent or calcineurin inhibitor, especially in lymphopenic individuals.

Infectious Complications With the Use of Biologic Response Modifiers in Infants and Children

Biologic response modifiers (BRMs) are substances that interact with and modify the host immune system. BRMs that dampen the immune system are used to treat conditions such as juvenile idiopathic arthritis, psoriatic arthritis, or inflammatory bowel disease and often in combination with other immunosuppressive agents, such as methotrexate and corticosteroids. Cytokines that are targeted include tumor necrosis factor α; interleukins (ILs) 6, 12, and 23; and the receptors for IL-1α (IL-1A) and IL-1β (IL-1B) as well as other molecules. Although the risk varies with the class of BRM, patients receiving immune-dampening BRMs generally are at increased risk of infection or reactivation with mycobacterial infections (Mycobacterium tuberculosis and nontuberculous mycobacteria), some viral (herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, hepatitis B) and fungal (histoplasmosis, coccidioidomycosis) infections, as well as other opportunistic infections. The use of BRMs warrants careful determination of infectious risk on the basis of history (including exposure, residence, and travel and immunization history) and selected baseline screening test results. Routine immunizations should be given at least 2 weeks (inactivated or subunit vaccines) or 4 weeks (live vaccines) before initiation of BRMs whenever feasible, and inactivated influenza vaccine should be given annually. Inactivated and subunit vaccines should be given when needed while taking BRMs, but live vaccines should be avoided unless under special circumstances in consultation with an infectious diseases specialist. If the patient develops a febrile or serious respiratory illness during BRM therapy, consideration should be given to stopping the BRM while actively searching for and treating possible infectious causes.

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Pneumocystis pneumonia complicating immunosuppressive therapy in Crohns disease: A preventable problem?

We report the case of a 76-year-old man who presented with moderate active Crohn's colitis that was refractory to high-dose corticosteroids, mesalazine and 6-mercaptopurine. He subsequently received a trial of infliximab with poor response and was diagnosed with cytomegalovirus (CMV) colitis, improving on antiviral therapy. Three weeks into treatment he developed acute respiratory distress with hypoxaemia and diffuse pulmonary interstitial infiltrates. This was confirmed as Pneumocystis jirovecii on bronchoalveolar lavage. He responded well to treatment with trimethoprim-sulfamethoxazole (TMP-SMX) and was subsequently discharged home. Despite the favourable outcome, our case raises the question of whether chemoprophylaxis against opportunistic infections in immunosuppressed patients with inflammatory bowel disease (IBD) is appropriate. There are currently no recommendations on providing chemoprophylaxis against CMV colitis and so we focus on pneumocystis pneumonia (PCP) where wide debate surrounds the use of prophylactic TMP-SMX in HIV-negative patients. Contrasting approaches to chemoprophylaxis against PCP in IBD likely relates to a lack of clear parameters for defining risk of PCP among patient groups. This must be addressed in order to develop universal guidelines that take into account patient-dependent risk factors. Awareness of the severity of PCP among HIV-negative individuals and the current consensus on PCP prophylaxis in IBD must be raised in order to minimise the risk of PCP and drive research in this controversial area.

NASPGHAN Clinical Report: Surveillance, Diagnosis, and Prevention of Infectious Diseases in Pediatric Patients With Inflammatory Bowel Disease Receiving Tumor Necrosis Factor-α Inhibitors

Children and adolescents with inflammatory bowel disease (IBD) receiving therapy with tumor necrosis factor α inhibitors (anti-TNFα) pose a unique challenge to health care providers in regard to the associated risk of infection. Published experience in adult populations with distinct autoinflammatory and autoimmune diseases treated with anti-TNFα therapies demonstrates an increased risk of serious infections with intracellular bacteria, mycobacteria, fungi, and some viruses; however, there is a paucity of robust pediatric data. With a rising incidence of pediatric IBD and increasing use of biologic therapies, heightened knowledge and awareness of infections in this population is important for primary care pediatricians, pediatric gastroenterologists, and infectious disease (ID) physicians. This clinical report is the result of a consensus review performed by pediatric ID and gastroenterology physicians detailing relevant published literature regarding infections in pediatric patients with IBD receiving anti-TNFα therapies. The objective of this document is to provide comprehensive information for prevention, surveillance, and diagnosis of infections based on current knowledge, until additional pediatric data are available to inform evidence-based recommendations.

Pneumocystis jirovecii pneumonia in a patient with pustular psoriasis with an IL-36RN deficiency treated with infliximab: Case report and review of the literature

Pneumocystis jirovecii pneumonia (PCP) is a relatively rare complication in non-HIV patients receiving immunosuppressive treatment. Since the introduction of tumour necrosis factor-α inhibitors cases of this complication have increased. We report the case of a 54-year-old, HIV-negative patient, who presented to our department with a long history of pustular psoriasis with poor response to traditional treatments. During the last admission he developed a severe flare that was unresponsive to cyclosporine, therefore infliximab was initiated. After the third dose he developed PCP that required admission to the intensive care unit, with a positive response to i.v. administration of trimethoprim/sulfamethoxazole. During follow up a mutation in the IL36RN gene compatible with an IL-36RN deficiency was found and anakinra was started, with rapid improvement of his psoriasis. PCP is a severe complication in patients receiving immunosuppressive therapy and is probably underreported by dermatologists. There are no clinical guidelines for PCP prophylaxis in dermatological patients who will receive immunosuppressive or biological treatments. We believe that it is necessary to report the cases of PCP to assess the real impact of this complication and develop appropriate prophylaxis guidelines.

Neither classical nor alternative macrophage activation is required for Pneumocystis clearance during immune reconstitution inflammatory syndrome

Pneumocystis is a respiratory fungal pathogen that causes pneumonia (Pneumocystis pneumonia [PcP]) in immunocompromised patients. Alveolar macrophages are critical effectors for CD4(+) T cell-dependent clearance of Pneumocystis, and previous studies found that alternative macrophage activation accelerates fungal clearance during PcP-related immune reconstitution inflammatory syndrome (IRIS). However, the requirement for either classically or alternatively activated macrophages for Pneumocystis clearance has not been determined. Therefore, RAG2(-/-) mice lacking either the interferon gamma (IFN-γ) receptor (IFN-γR) or interleukin 4 receptor alpha (IL-4Rα) were infected with Pneumocystis. These mice were then immune reconstituted with wild-type lymphocytes to preserve the normal T helper response while preventing downstream effects of Th1 or Th2 effector cytokines on macrophage polarization. As expected, RAG2(-/-) mice developed severe disease but effectively cleared Pneumocystis and resolved IRIS. Neither RAG/IFN-γR(-/-) nor RAG/IL-4Rα(-/-) mice displayed impaired Pneumocystis clearance. However, RAG/IFN-γR(-/-) mice developed a dysregulated immune response, with exacerbated IRIS and greater pulmonary function deficits than those in RAG2 and RAG/IL-4Rα(-/-) mice. RAG/IFN-γR(-/-) mice had elevated numbers of lung CD4(+) T cells, neutrophils, eosinophils, and NK cells but severely depressed numbers of lung CD8(+) T suppressor cells. Impaired lung CD8(+) T cell responses in RAG/IFN-γR(-/-) mice were associated with elevated lung IFN-γ levels, and neutralization of IFN-γ restored the CD8 response. These data demonstrate that restricting the ability of macrophages to polarize in response to Th1 or Th2 cytokines does not impair Pneumocystis clearance. However, a cell type-specific IFN-γ/IFN-γR-dependent mechanism regulates CD8(+) T suppressor cell recruitment, limits immunopathogenesis, preserves lung function, and enhances the resolution of PcP-related IRIS.

Pneumocystis jirovecii Pneumonia in Rheumatoid Arthritis Patients: Risks and Prophylaxis Recommendations

Pneumocystis jirovecii infection causes fulminant interstitial pneumonia (Pneumocystis pneumonia, PCP) in patients with rheumatoid arthritis (RA) who are receiving biological and/or nonbiological antirheumatic drugs. Recently, we encountered a PCP outbreak among RA outpatients at our institution. Hospital-acquired, person-to-person transmission appears to be the most likely mode of this cluster of P. jirovecii infection. Carriage of P. jirovecii seems a time-limited phenomenon in immunocompetent hosts, but in RA patients receiving antirheumatic therapy, clearance of this organism from the lungs is delayed. Carriers among RA patients can serve as sources and reservoirs of P. jirovecii infection for other susceptible patients in outpatient facilities. Development of PCP is a matter of time in such carriers. Considering the poor survival rates of PCP cases, prophylactic antibiotics should be considered for RA patients who are scheduled to receive antirheumatic therapy. Once a new case of PCP occurs, we should take prompt action not only to treat the PCP patient but also to prevent other patients from becoming new carriers of P. jirovecii. Short-term prophylaxis with trimethoprim-sulfamethoxazole is effective in controlling P. jirovecii infection and preventing future outbreaks of PCP among RA patients.

Biological agents and respiratory infections: Causative mechanisms and practice management

Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents.

Pneumocystis jirovecii pneumonia in patients receiving tumor-necrosis-factor-inhibitor therapy: implications for chemoprophylaxis

Pneumocystis jirovecii pneumonia (PJP) is an important opportunistic infection that has been increasingly reported in patients with rheumatic disease. Reported incidence among patients taking TNF inhibitors (TNFi) has varied, but has usually been low. Still, disease causes significant mortality among those affected and must be considered in patients with rheumatological disease presenting with dyspnea and cough. Diagnosis can be difficult in the non-HIV population, and our understanding of the epidemiology and natural history after exposure is changing. Trimethoprim-sulfamethoxazole is believed to be the most effective agent for treatment and prophylaxis, but is associated with significant adverse effects. Given the low incidence reported in most studies of patients on TNFi, prophylaxis is probably not beneficial for this patient population as a whole.