Pneumocystis pneumonia during combined therapy of infliximab, corticosteroid, and azathioprine in a patient with Crohn's disease

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.

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.

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.

Increased dosage of infliximab is a potential cause of Pneumocystis carinii pneumonia

Methods

Pneumocystis carinii pneumonia occasionally appears in immunodeficient patients. While several reports have shown that Pneumocystis carinii pneumonia occurred in the early phase of starting infliximab treatment in patients with Crohn’s disease (CD), the present case suggests for the first time that an increased dosage of infliximab may also lead to pneumonia.

Results

A 51-year-old male had been taking 5 mg of infliximab for the treatment of CD for 10 years with no adverse events. Beginning in September 2013, the dose of infliximab had to be increased to 10 mg/kg because his status worsened. Thereafter, he complained of a fever and cough, and a CT scan revealed ground-glass opacities in the lower lobes of the bilateral lung with a crazy-paving pattern. Bronchoscopy detected swelling of the tracheal mucosa with obvious dilations of the vessels. A polymerase chain reaction using a bronchoalveolar lavage fluid sample detected specific sequences for Pneumocystis jirovecii; thus he was diagnosed with Pneumocystis carinii (jirovecii) pneumonia. After discontinuing infliximab and starting antibiotic treatment, his symptoms and CT findings were dramatically improved.

Conclusions

The administration of an increased dosage of infliximab can cause Pneumocystis carinii pneumonia in CD patients.

B cell production of tumor necrosis factor in response to Pneumocystis murina infection in mice

Pneumocystis species are opportunistic fungal pathogens that induce tumor necrosis factor (TNF) production by alveolar macrophages. Here we report that B cells from the draining lymph nodes as well as lung CD4(+) T cells are important producers of TNF upon Pneumocystis murina infection. To determine the importance of B cell-derived TNF in the primary response to P. murina, we generated bone marrow chimeras whose B cells were unable to produce TNF. The lung P. murina burden at 10 days postinfection in TNF knockout (TNFKO) chimeras was significantly higher than that in wild-type (WT) chimeras, which corresponded to reduced numbers of activated CD4(+) T cells in the lungs at this early time point. Furthermore, CD4(+) T cells isolated from P. murina-infected TNFKO chimeras were unable to stimulate clearance of P. murina upon adoptive transfer to recombinase-deficient (RAG1KO) hosts. Together, these data indicate that B cell-derived TNF plays an important function in promoting CD4(+) T cell expansion and production of TNF and facilitating protection against P. murina infection.

Pneumocystis jirovecii pneumonia in non-HIV-infected patients in the era of novel immunosuppressive therapies

In human immunodeficiency virus (HIV)-infected patients, Pneumocystis jirovecii pneumonia (PCP) is a well-known opportunistic infection, and its management has been established. However, PCP is an emerging threat to immunocompromised patients without HIV infection, such as those receiving novel immunosuppressive therapeutics for malignancy, organ transplantation, or connective tissue diseases. Clinical manifestations of PCP are quite different between patients with and without HIV infections. In patients without HIV infection, PCP rapidly progresses, is difficult to diagnose correctly, and causes severe respiratory failure with a poor prognosis. High-resolution computed tomography findings are different between PCP patients with HIV infection and those without. These differences in clinical and radiologic features are the result of severe or dysregulated inflammatory responses that are evoked by a relatively small number of Pneumocystis organisms in patients without HIV infection. In recent years, the usefulness of PCR and serum β-D-glucan assay for rapid and noninvasive diagnosis of PCP has been revealed. Although corticosteroid adjunctive to anti-Pneumocystis agents has been shown to be beneficial in some populations, the optimal dose and duration remain to be determined. Recent investigations revealed that Pneumocystis colonization is prevalent, and that asymptomatic carriers are at risk for developing PCP and can serve as the reservoir for the spread of Pneumocystis by person-to-person transmission. These findings suggest the need for chemoprophylaxis in immunocompromised patients without HIV infection, although its indication and duration are still controversial. Because a variety of novel immunosuppressive therapeutics have been emerging in medical practice, further innovations in the diagnosis and treatment of PCP are needed.

Pneumocystosis in a patient with Crohn's disease treated with combination therapy with adalimumab

Pneumocystis jirovecii pneumonia (PCP) is a potential complication of immunosuppression. Crohn's disease (CD) is an immune granulomatous disorder characterized by transmural inflammation that can affect any part of the gastrointestinal tract. Its treatment is based on steroids and immunosuppressants but in non-responders, biologic compounds such as anti-tumor necrosis factor alpha (TNF) antibodies have been used. Neutralization of TNF causes a decrease in the inflammatory response but increases susceptibility to opportunistic infections such as fungal infections. We report a young male with chronic diarrhea, fever and weight loss who was diagnosed with CD and began conventional treatment with immunosuppressants, but due to lack of response after several weeks, biologic therapy with adalimumab was initiated. Seven weeks later he developed persistent fever and upper respiratory symptoms. After chest CT, bronchoscopy and bronchial lavage, P. jirovecii was identified by silver staining and confirmed by immunofluorescence. To our knowledge this is the second case of pneumocystosis associated with the use of adalimumab in CD and the first reported Mexican case confirmed by microbiological and immunological studies in this setting.

Pneumocystis jirovecii pneumonia in non-HIV-infected patients: new risks and diagnostic tools

PURPOSE OF REVIEW

Non-HIV-infected populations are increasingly identified as being at risk for developing Pneumocystis jirovecii pneumonia (PJP). These patients typically present with severe disease and poorly tolerate invasive diagnostic procedures. This review examines recently reported risks for PJP in non-HIV populations and summarizes new diagnostic techniques.

RECENT FINDINGS

PJP is associated with immunomodulatory drug therapies, including monoclonal antibody therapies such as tumour necrosis factor α antagonists, and calcineurin inhibitors. Underlying disease states include solid-organ transplantation, connective tissue and rheumatologic disorders, inflammatory bowel disease, haematological malignancies, and solid tumours. Modern diagnostic techniques [conventional PCR, quantitative PCR, (1→3)-β-D-glucan assays, and PET] are reviewed with respect to predictive value and clinical utility. In particular, current literature regarding validation and specificity of molecular diagnostic techniques is summarized, including application to minimally invasive specimens.

SUMMARY

HIV-negative populations at risk for PJP can be identified. Conventional PCR increases diagnostic sensitivity but may detect asymptomatic colonization. Quantitative PCR demonstrates potential for distinguishing colonization from infection, but clinical validation is required. Serum (1→3)-β-D-glucan may be elevated in PJP, although standardized cut-off values for clinical infection have not been determined. Further validation of serum markers and molecular diagnostic methods is necessary for early and accurate diagnosis in non-HIV populations.

[Non tuberculous anti-TNF associated opportunistic infections]

Anti-TNFalpha agents have revolutionized the treatment of patients with rheumatoid arthritis, spondylarthropathies and Crohn's disease. However, their use is associated with an increased risk of infections. Pyogenic infections (involving the lungs, skin and urinary tract) and tuberculosis are the more commonly observed infectious complications in patients receiving anti-TNFalpha agents. However, opportunistic infections have been increasingly reported in anti-TNFalpha-treated patients, and include non tuberculous mycobacteria, fungi (Pneumocystis jiroveci, Candida sp, Aspergillus, Cryptococcus, Histoplasma), opportunistic bacterial (Nocardia), parasitic (Leishmania) and viral (e.g. Cytomegalovirus, human herpes virus 8 [HHV 8]) infections. These infectious complications usually occur within the first months of therapy and are important causes of morbidity and mortality in anti-TNFalpha-treated patients. It is recommended to rule out infections, especially latent or active tuberculosis, before the initiation of anti-TNFalpha therapy. However, it is necessary to follow-up closely these patients to detect the possible occurrence of opportunistic infections.

Immunizations in patients with inflammatory bowel disease

Patients receiving immunosuppressive therapies may be at increased risk for complications of vaccine preventable diseases, including influenza, varicella, and pneumococcus. However, studies suggest that patients with chronic illness may be inadequately immunized. In part, this is because of a paucity of formal vaccine studies in immune compromised populations. This review discusses the methods one uses to assess vaccine efficacy and provides an update on currently known data on the vaccine antibody responses in immune compromised hosts. Currently published studies suggest that influenza vaccine can be safely administered to patients with IBD on immunosuppression, and is effective in the majority of patients. Further formal studies with other inactivated vaccines (e.g., pneumococcal vaccine, meningitis vaccine) should be conducted. While some studies in immune compromised hosts suggest the live attenuated varicella vaccine can be given without adverse events, administration of this vaccine in patients on immunosuppression remains controversial.

Biofilm formation by Pneumocystis spp

Pneumocystis spp. can cause a lethal pneumonia in hosts with debilitated immune systems. The manner in which these fungal infections spread throughout the lung, the life cycles of the organisms, and their strategies used for survival within the mammalian host are largely unknown, due in part to the lack of a continuous cultivation method. Biofilm formation is one strategy used by microbes for protection against environmental assaults, for communication and differentiation, and as foci for dissemination. We posited that the attachment and growth of Pneumocystis within the lung alveoli is akin to biofilm formation. An in vitro system comprised of insert wells suspended in multiwell plates containing supplemented RPMI 1640 medium supported biofilm formation by P. carinii (from rat) and P. murina (from mouse). Dramatic morphological changes accompanied the transition to a biofilm. Cyst and trophic forms became highly refractile and produced branching formations that anastomosed into large macroscopic clusters that spread across the insert. Confocal microscopy revealed stacking of viable organisms enmeshed in concanavalin A-staining extracellular matrix. Biofilms matured over a 3-week time period and could be passaged. These passaged organisms were able to cause infection in immunosuppressed rodents. Biofilm formation was inhibited by farnesol, a quorum-sensing molecule in Candida spp., suggesting that a similar communication system may be operational in the Pneumocystis biofilms. Intense staining with a monoclonal antibody to the major surface glycoproteins and an increase in (1,3)-beta-D-glucan content suggest that these components contributed to the refractile properties. Identification of this biofilm process provides a tractable in vitro system that should fundamentally advance the study of Pneumocystis.