Pneumocystis carinii pneumonia in patients without predisposing illnesses. Acute episode and follow-up of five cases

Pneumocystis jirovecii pneumonia in a healthy immunocompetent patient: A case report and literature review

Pneumocystis jirovecii pneumonia, typically an opportunistic infection, is commonly associated with risk factors such as low CD4+ lymphocyte count, underlying malignancies, organ transplantation, or immunosuppressive medications. However, occurrences in healthy individuals without known risk factors are exceptionally rare and sparsely documented. In our retrospective analysis of a 42-year-old male without past medical history at Abderrahmane Mami Hospital, Tunisia, Pneumocystis jirovecii pneumonia was diagnosed. The patient presented with fever, productive cough, hemoptysis, and a decline in general health. Clinical examination revealed fever and hypoxemia, and imaging studies demonstrated bilateral necrotic alveolar opacities. Despite empirical antibiotics, nonresponse necessitated bronchoscopy, confirming Pneumocystis jirovecii. Treatment with oral Sulfamethoxazole-Trimethoprim yielded excellent outcomes. This case highlights the potential occurrence of Pneumocystis jirovecii pneumonia in immunocompetent individuals, underscoring the importance of direct microbiological methods in assessing suggestive clinical and radiological features.

Study on the Prevalence of Pneumocystis jirovecii as a Causative Agent of Lung Pathology in People with Different Immune Status

BACKGROUND

Pneumocystis pneumonia (PCP) commonly affects immunocompromised individuals, whereas in immunocompetent persons, it occurs relatively rarely, and in most cases, the Pneumocystis infection is detected as an asymptomatic colonization. The present study aimed to establish the prevalence of Pneumocystis jirovecii infection in human hosts with different immune status (immunocompromised and immunocompetent), using molecular diagnostic methods, and to compare their diagnostic value with that of classical staining methods.

METHODS

We used the collected-to-this-moment data from a prospective study on the prevalence of pneumocystosis among the Bulgarian population. Clinical specimens (including throat secretions, induced sputum, tracheal aspirates, and bronchoalveolar lavage) collected from 220 patients suspected of PCP (153 immunocompetent and 67 immunocompromised patients) were examined with microscopic staining methods and real-time PCR for detection of P. jirovecii. Results: DNA of the pathogen was detected in 38 (17%) specimens (32 immunocompromised patients and 6 immunocompetent subjects). From all 220 clinical samples examined by staining methods, only five (2%) P. jirovecii cysts were detected by the Gomori stain. All patients with PCP were treated with trimethoprim-sulfamethoxazole, but in ten of them (HIV-positive patients), the disease had a fatal outcome.

CONCLUSIONS

This study is the first in Bulgaria including the main available laboratory methods for diagnosis of human pneumocystosis. Regarding the etiological diagnosis of PCP, in our study the sensitivity of real-time PCR was higher compared to the staining methods. The choice of a method for sample collection and examination has an important role in the efficiency of the laboratory diagnostics.

A comprehensive clinical guide for Pneumocystis jirovecii pneumonia: a missing therapeutic target in HIV-uninfected patients

INTRODUCTION

Pneumocystis jirovecii is an opportunistic, human-specific fungus that causes Pneumocystis pneumonia (PCP). PCP symptoms are nonspecific. A patient with P. jirovecii and another lung infection faces a diagnostic challenge. It may be difficult to determine which of these agents is responsible for the clinical symptoms, preventing effective treatment. Diagnostic and treatment efforts have been made more difficult by the rising frequency with which coronavirus 2019 (COVID-19) and PCP co-occur.

AREAS COVERED

Herein, we provide a comprehensive review of clinical and pharmacological recommendations along with a literature review of PCP in immunocompromised patients focusing on HIV-uninfected patients.

EXPERT OPINION

PCP may be masked by identifying co-existing pathogens that are not necessarily responsible for the observed infection. Patients with severe form COVID-19 should be examined for underlying immunodeficiency, and co-infections must be considered as co-infection with P. jirovecii may worsen COVID-19's severity and fatality. PCP should be investigated in patients with PCP risk factors who come with pneumonia and suggestive radiographic symptoms but have not previously received PCP prophylaxis. PCP prophylaxis should be explored in individuals with various conditions that impair the immune system, depending on their PCP risk.

Increased susceptibility to pneumonia due to tumour necrosis factor inhibition and prospective immune system rescue via immunotherapy

Immunomodulators such as tumour necrosis factor (TNF) inhibitors are used to treat autoimmune conditions by reducing the magnitude of the innate immune response. Dampened innate responses pose an increased risk of new infections by opportunistic pathogens and reactivation of pre-existing latent infections. The alteration in immune response predisposes to increased severity of infections. TNF inhibitors are used to treat autoimmune conditions such as rheumatoid arthritis, juvenile arthritis, psoriatic arthritis, transplant recipients, and inflammatory bowel disease. The efficacies of immunomodulators are shown to be varied, even among those that target the same pathways. Monoclonal antibody-based TNF inhibitors have been shown to induce stronger immunosuppression when compared to their receptor-based counterparts. The variability in activity also translates to differences in risk for infection, moreover, parallel, or sequential use of immunosuppressive drugs and corticosteroids makes it difficult to accurately attribute the risk of infection to a single immunomodulatory drug. Among recipients of TNF inhibitors, Mycobacterium tuberculosis has been shown to be responsible for 12.5-59% of all infections; Pneumocystis jirovecii has been responsible for 20% of all non-viral infections; and Legionella pneumophila infections occur at 13-21 times the rate of the general population. This review will outline the mechanism of immune modulation caused by TNF inhibitors and how they predispose to infection with a focus on Mycobacterium tuberculosis, Legionella pneumophila, and Pneumocystis jirovecii. This review will then explore and evaluate how other immunomodulators and host-directed treatments influence these infections and the severity of the resulting infection to mitigate or treat TNF inhibitor-associated infections alongside antibiotics.

Pneumocystis pneumonia in an immunocompetent patient developing a subacute disease course with central consolidation

Pneumocystis pneumonia (PCP) typically occurs in immunocompromised individuals and rarely presents in immunocompetent individuals. A 55-year-old man was referred to our hospital with cough and anorexia that persisted for 2 months. Chest computed tomography revealed bilateral central consolidation. He was diagnosed with PCP via bronchoscopy. His symptoms and imaging findings improved with the administration of only trimethoprim and sulfamethoxazole. Although he had non-alcoholic fatty liver disease, there were no other complications that could potentially cause immunodeficiency. It should be noted that PCP in immunocompetent individuals can have a subacute disease course presenting with bilateral central consolidation.

Clinical characteristics and prognosis of patients with Pneumocystis jirovecii pneumonia without a compromised illness

Objective

Pneumocystis jirovecii pneumonia (PCP) is a fatal respiratory infection, mostly associated with immunocompromised conditions. Several reports have described PCP development in patients who were not immunocompromised, but the clinical course and prognosis of PCP are not well understood. We compared the clinical characteristics and prognoses between patients with and without immunocompromised conditions who developed PCP.

Methods

We retrospectively analyzed patients who had been treated for PCP from three hospitals. We defined immunocompromised (IC) status as following: human immunodeficiency virus (HIV) infection; hematological malignancy; solid organ tumor under chemotherapy; rheumatic disease; medication with immunosuppressive agents. Patients without immunocompromised status were defined as being non-immunocompromised (non-IC).

Results

The IC and non-IC groups comprised 173 and 14 patients. The median ages were 62.0 and 74.0 years in the IC and the non-IC group, respectively. The median interval between admission and anti-PCP treatment was significantly longer for patients in the non-IC group than that for patients in the IC group (7 vs. 2 days). The in-hospital mortality rates were significantly higher for patients in the non-IC group than that for patients in the IC group (71.4% vs. 43.9%; P = 0.047). A longer interval between admission and anti-PCP therapy was associated with increased 90-day mortality rate in patients with PCP (hazard ratio, 1.082; 95% confidence interval, 1.015–1.153; P = 0.016).

Conclusions

Patients with PCP with no predisposing illnesses were older and had higher mortality rates than IC patients with PCP. Delayed anti-PCP treatment was associated with increased 90-day mortality.

Possible Diagnostic Delays and Missed Prevention Opportunities in Pneumocystis Pneumonia Patients Without HIV: Analysis of Commercial Insurance Claims Data-United States, 2011-2015

Background

Pneumocystis pneumonia (PCP) is a life-threatening but treatable and preventable fungal infection in immunocompromised persons. Previous studies suggest that persons without HIV who develop PCP (PCPHIV-) experience more acute, severe illness than persons with HIV who develop PCP (PCPHIV+). We analyzed health insurance claims data to compare demographics, underlying conditions, symptoms, and prescriptions for PCPHIV+ and PCPHIV-.

Methods

We used the IBM MarketScan Research Databases to identify patients diagnosed with PCP during 2011-2015. We analyzed claims 1 year before to 3 months after diagnosis to compare PCPHIV+ and PCPHIV-.

Results

Among 3938 patients, 70.4% were PCPHIV-. Compared with PCPHIV+, PCPHIV- were more likely to be older (median, 60 vs 45 years; P < .0001), female (51.5% vs 20.2%; P < .0001), hypoxemic (13.5% vs 7.1%; P < .0001), and to die within 90 days (6.6% vs 4.2%; P < .0001). The most common underlying conditions among PCPHIV- included chronic pulmonary diseases (54.6%), solid tumors (35.1%), hematologic malignancies (20.1%), and rheumatologic conditions (14.0%). The median time between the first visit for PCP-related symptoms and PCP diagnosis was longer for PCPHIV- than PCPHIV+ (25 vs 16 days; P < .0001). In the 3 months before PCP diagnosis, PCPHIV- were less likely to have an outpatient prescription for PCP prophylaxis than PCPHIV+ (6.9% vs 10.6%; P = .0001).

Conclusions

PCPHIV- may experience a prolonged illness course and diagnostic delays compared with PCPHIV+. Clinicians should maintain a high index of suspicion for PCP in immunocompromised patients with compatible symptoms, regardless of HIV status.

Pneumocystis jirovecii Pneumonia in an Immunocompetent Japanese Man: A Case Report and Literature Review

We herein report the case of a 37-year-old immunocompetent man who died from Pneumocystis jirovecii pneumonia (PCP). He was initially treated for an acute exacerbation of interstitial pneumonia; however, the elevation of the patient's serum (1-3) β-D glucan (BG) level suggested the possibility of PCP and sulfamethoxazole trimethoprim was added. A postmortem pathological examination and retrospective Grocott's methenamine silver (GMS) staining of the bronchoalveolar lavage fluid (BALF), which was obtained on the day of admission, revealed PCP. The present case suggests that it is essential to perform a BG assay and GMS staining of BALF specimens when patients show diffuse ground-glass opacity on chest computed tomography, regardless of their immune status.

Pneumocystis Jiroveci Pneumonia and Newly Diagnosed Human Immunodeficiency Virus (AIDS) in a 63-Year-Old Woman

Patient: Female, 63

Final Diagnosis: Pneumocystis jirovici pneumonia

Symptoms: Cough

Medication: —

Clinical Procedure: Bronchoscopy

Specialty: Infectious Diseases

Pneumocystis jirovecii infection in patients with acute interstitial pneumonia

OBJECTIVE

Acute interstitial pneumonia (AIP) is a severe disease of unknown etiology. Pneumocystis jirovecii is an atypical opportunistic fungus able to colonize patients with chronic pulmonary disease and inducing alveolar macrophage activation. The aim of this study was to evaluate the possible association between Pneumocystis jirovecii and AIP.

SUBJECTS AND METHODS

The presence of P. jirovecii in bronchoalveolar lavage fluid in the four confirmed cases of AIP identified in a tertiary-care hospital over a period of nine years was studied using a 2-step nested-PCR protocol assay.

RESULTS

P. jirovecii was identified in the four cases. None of them had HIV infection. Two of the patients were treated empirically with trimethoprim-sulfamethoxazole, the only survivor was being one of them.

CONCLUSIONS

Our data suggest that Pneumocystis could trigger or favor the development of AIP. Further studies are needed to evaluate the role of the pathogen in the physiopathology of this disease.

Granulomatous PJP presenting as a solitary lung nodule in an immune competent female

Pneumocystis jiroveci pneumonia (PJP) opportunistically targets immunosuppressed patients, most notably those with advanced HIV/AIDS. Radiologically, PJP typically appears as bilateral diffuse pulmonary infiltrates. Herein an unusual case of an immunocompetent woman developing granulomatous PJP in the absence of evident risk factors is described. PJP may be an under-recognized cause of pulmonary nodules in immune competent individuals.

Pneumocystis jirovecii colonization in chronic pulmonary disease

Pneumocystis jirovecii causes pneumonia in immunosuppressed individuals. However, it has been reported the detection of low levels of Pneumocystis DNA in patients without signs and symptoms of pneumonia, which likely represents colonization. Several studies performed in animals models and in humans have demonstrated that Pneumocystis induces a local and a systemic response in the host. Since P. jirovecii colonization has been found in patients with chronic pulmonary diseases it has been suggested that P. jirovecii may play a role in the physiopathology and progression of those diseases. In this report we revise P. jirovecii colonization in different chronic pulmonary diseases such us, chronic obstructive pulmonary disease, interstitial lung diseases, cystic fibrosis and lung cancer.

Fact or fiction: does the non-HIV/AIDS immunosuppressed patient need Pneumocystis jiroveci pneumonia prophylaxis? An updated literature review

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is a potentially fatal fungal infection occurring in immunocompromised patients.

OBJECTIVE

To determine whether PJP prophylaxis is required in the non-human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) immunocompromised patient and, if so, the optimal prophylactic therapy.

METHODS

A thorough literature review, with the appropriate MeSH terms, was conducted using PubMed, Medline, and The Cochrane Database. A number of cases describing PJP in patients with various systemic diseases and immunosuppressive medications, along with a Cochrane review, were highlighted.

RESULTS

Although there are a number of case reports in the literature, the only collagen vascular disease with an increased incidence of PJP is Wegener granulomatosis. Oral trimethoprim-sulfamethoxazole continues to be the prophylaxis of choice for PJP.

CONCLUSION

There is currently no evidence to recommend PJP prophylaxis in the non-HIV/AIDS immunocompromised population. If physicians do decide to use prophylaxis, they should always weigh the benefits with the potential risks. Further studies are needed to better quantify the risks of PJP with immunosuppressive medications.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

Pneumocystis jirovecii colonisation in patients with interstitial lung disease

A prospective study was conducted to determine the prevalence of colonisation by Pneumocystis jirovecii in 80 consecutive patients who required bronchoscopy and bronchoalveolar lavage (BAL) following suspicion of interstitial lung disease (ILD). The mtLSU rRNA gene of P. jirovecii was identified by nested PCR in BAL samples. Patients with ILDs were divided into three groups: group A comprised those with idiopathic interstitial pneumonias; group B comprised those with sarcoidosis; and group C comprised those with other ILDs. The overall prevalence of P. jirovecii carriage was 33.8%, with colonisation rates of 37.8%, 18.8% and 37% in groups A, B and C, respectively (p not significant). There were more smokers among the carriers, but there were no other significant differences between carriers and non-carriers. The high prevalence of P. jirovecii carriers found among immunocompetent patients with ILDs in Spain suggests a possible role of P. jirovecii in the natural history of these diseases.

Epidemiology of Pneumocystis carinii pneumonia in southern Spain

In order to investigate the impact of Pneumocystis carinii infection in southern Spain following the introduction of highly active anti-retroviral therapy (HAART), all cases of pneumocystosis between 1998 and 1999 were identified from data compiled by the national surveillance system. In total, 498 cases of pneumocystosis were recorded, of which 87% involved HIV-positive patients. The mean age, length of hospital stay and mortality were higher for HIV-negative patients. There was a higher number of cases in winter. Despite HAART implementation, pneumocystosis remains a significant health problem for both HIV-positive and HIV-negative patients.

Association between human-Pneumocystis infection and small-cell lung carcinoma

BACKGROUND

Tobacco smoking is the most important but not the only risk factor in lung carcinoma. There is evidence that certain infections, which cause chronic inflammatory reactions, can also induce tumour development. It has recently been shown that patients with chronic pulmonary diseases present a high rate of subclinical Pneumocystis infection, and that the latter is able to induce inflammatory responses and alveolar cell alterations. The possible role of Pneumocystis infection in the development of lung neoplasms thus deserves consideration.

MATERIAL AND METHODS

Polymerase chain reaction has been used to analyze the presence of DNA of two independent loci of the Pneumocystis genome: the mitochondrial region (mtLSU rRNA) and the gene encoding for the dihydropteroate synthase enzyme, in paraffin-embedded tissue blocks of 10 cases of small cell lung carcinoma (SCLC) and 10 cases of nonsmall cell lung carcinoma (NSCLC) with similar demographic and clinical characteristics. Five cases without lung pathology, and two cases of Pneumocystis pneumonia were also analyzed as controls.

RESULTS

DNA of the microorganism was found in all the cases of SCLC but in only two of the NSCLC, and in none of the controls without pulmonary disease - thus implying a statistically significant association (P < 0.0001) between subclinical Pneumocystis infection and SCLC.

CONCLUSIONS

While the nature of this association is not clear, it nevertheless constitutes an important finding - either the infection is specifically facilitated by this tumour or induces the development of this type of neoplasm in combination with other factors. Eur J Clin Invest 2004; 34 (3): 229-335

Pneumocystis carinii pneumonia in patients with and without HIV infection

Advances in the prevention and treatment of Pneumocystis carinii pneumonia in HIV infected patients have led to a decrease in the incidence and improved outcomes. Pneumocystis carinii pneumonia continues to be problematic in non-HIV infected immunocompromised patients.

Opportunistic infections in patients with and patients without Acquired Immunodeficiency Syndrome

In the next decade, longer survival of patients with cancer and more-aggressive therapies applied to common conditions, such as asthma and rheumatoid arthritis, will result in a larger population with significant immune system defects. Many in this population will be at risk for opportunistic infections, which are familiar to doctors who have treated people infected with human immunodeficiency virus (HIV). However, the epidemiology, presentation, and outcome of these infections in patients with an immune system defect, other than that caused by HIV infection, may be different than those encountered in patients with acquired immunodeficiency syndrome. Reviewed are 4 common opportunistic infections: Pneumocystis carinii pneumonia, cryptococcosis, atypical mycobacterial infection, and cytomegalovirus infection. Emphasized are the important differences among these groups at risk.

Bronchoscopic diagnosis of pneumonia

Lower respiratory tract infections are characterized by significant morbidity and mortality but also by a relative inability to establish a specific etiologic agent on clinical grounds alone. With the recognized shortcomings of expectorated or aspirated secretions toward establishing an etiologic diagnosis, clinicians have increasingly used bronchoscopy to obtain diagnostic samples. A variety of specimen types may be obtained, including bronchial washes or brushes, protected specimen brushings, bronchoalveolar lavage, and transbronchial biopsies. Bronchoscopy has been applied in three primary clinical settings, including the immunocompromised host, especially human immunodeficiency virus-infected and organ transplant patients; ventilator-associated pneumonia; and severe, nonresolving community- or hospital-acquired pneumonia in nonventilated patients. In each clinical setting, and for each specimen type, specific laboratory protocols are required to provide maximal information. These protocols should provide for the use of a variety of rapid microscopic and quantitative culture techniques and the use of a variety of specific stains and selective culture to detect unusual organism groups.

New pathogens in pneumonia

It appears that many commonly recognized syndromes such as the ARDS may well be caused by agents that have only recently emerged as respiratory pathogens. HPS represents one such entity. It appears likely that the increasing pressure of antibiotic use as well as the reemergence of certain pathogens will continue to challenge the clinician. Paramount to the identification and treatment of unusual pneumonias will be the degree with which an effort is made to make an etiologic diagnosis through sputum examination, transtracheal aspirate, bronchoscopy, or lung biopsy. Although pneumococcal pneumonia is the most common community-acquired pneumonia seen by practicing physicians, in all likelihood from time to time a physician will encounter pneumonia caused by one of the unusual pathogens described in this article or else by an altogether new pathogen.