Pneumocystis jirovecii Pneumonia in Patients Without HIV: A UK 5-Year Retrospective Study
Key Points:
1. Pneumocystis jirovecii pneumonia (PCP) is increasingly affecting patients without HIV, especially those with cancer or autoimmune diseases.
2. Patients with rheumatological and autoimmune diseases are at higher risk of PCP.
3. PCP prophylaxis should be considered for high-risk patients on long-term immunosuppressive therapies.
Introduction:
PCP, once associated with HIV/AIDS, now affects patients with malignancies, autoimmune diseases, and immunosuppressive therapies. This study examines PCP cases in a UK hospital over 5 years.
Rising Trend:
PCP incidence is increasing in non-HIV populations due to aging, autoimmune diseases, malignancies, and immunosuppressive therapies. This trend is supported by studies in Germany and England.
Risk Factors:
Haematological malignancies, autoimmune diseases (e.g., rheumatoid arthritis, systemic lupus erythematosus), organ/bone marrow transplants, and solid tumours are significant risk factors for non-HIV PCP.
Diagnosis and Treatment:
PCP diagnosis relies on clinical, radiological, or microbiological evidence. Treatment includes high-dose cotrimoxazole and prednisolone. In-hospital fatality rates are high, especially in patients without cancer.
Study Methodology:
The study analysed 33 PCP cases diagnosed between 2019-2023 in a UK hospital. Patients were categorised by cancer status, with haematological and non-haematological malignancies.
Results:
Most patients were men (55%) with a mean age of 62.85 years. Shortness of breath and fever were common symptoms. Most patients without cancer had autoimmune/rheumatological conditions, followed by COPD, diabetes, solid organ transplant, and hepatitis C.
Diagnostic Challenges:
Chest X-rays were common, but CT scans were less frequent. Sputum induction and bronchoscopy with BAL were used in some patients, with positive P. jirovecii DNA in 50% of sputum cases and 85% of BAL cases.
Biomarker Analysis:
Procalcitonin (PCT) levels were low in most patients, with no significant difference in fatality rates. β-D-glucan (BDG) was positive in 45% of patients, with no impact on in-hospital fatality.
Mortality Analysis:
In-hospital fatality was 27%, higher in patients without cancer (39%). However, this difference was not statistically significant.
Discussion:
PCP is increasingly prevalent in non-HIV patients, especially with autoimmune diseases and immunosuppressive therapies. The study highlights the importance of clinical suspicion and risk assessment tools for high-risk patients.
Limitations:
The study's small sample size and reliance on ICD coding may have affected conclusions. Detailed immunosuppressive data and potential confounding factors were not fully available.
Conclusion:
The study emphasises the rising PCP incidence in non-HIV patients and the need for improved risk assessment tools to guide prophylaxis strategies.
