When do you prophylactically treat someone for Pneumocystis jirovecii pneumonia (PJP)?

From the Guidelines

Prophylactic treatment for PJP should be initiated in HIV-infected adults and adolescents when the CD4+ T lymphocyte count falls below 200 cells/μL or if the patient has a history of oropharyngeal candidiasis, as recommended by the guidelines 1. The guidelines suggest that trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred prophylactic agent, with a recommended dosage of one double-strength tablet daily or three times weekly 1. Some key points to consider when initiating prophylaxis include:

• CD4+ T lymphocyte count: prophylaxis should be initiated when the count falls below 200 cells/μL 1
• History of oropharyngeal candidiasis: patients with a history of oropharyngeal candidiasis should also receive prophylaxis 1
• Alternative regimens: for patients who cannot tolerate TMP-SMX, alternatives include dapsone, atovaquone, or aerosolized pentamidine 1 The first-line prophylactic regimen is trimethoprim-sulfamethoxazole (TMP-SMX), typically given as one double-strength tablet (160 mg/800 mg) daily or three times weekly 1. It is essential to continue prophylaxis until the patient's immune function improves, which for HIV patients means until CD4 counts remain above 200 cells/μL for at least 3-6 months on antiretroviral therapy 1. PJP prophylaxis is crucial because the infection can be life-threatening in immunocompromised individuals, and the medication prevents the colonization and proliferation of Pneumocystis jirovecii in the lungs, significantly reducing the risk of developing this opportunistic infection 1.

From the FDA Drug Label

For the prevention of Pneumocystis jirovecii pneumonia (PCP) in adults and adolescents (aged 13 years and older) who cannot tolerate trimethoprim-sulfamethoxazole (TMP-SMX). For the treatment of documented Pneumocystis carinii pneumonia and for prophylaxis against Pneumocystis carinii pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing Pneumocystis carinii pneumonia.

Prophylactic treatment for Pneumocystis jirovecii pneumonia (PJP) should be considered in individuals who are immunosuppressed and at an increased risk of developing PJP. This includes patients who cannot tolerate trimethoprim-sulfamethoxazole (TMP-SMX), a first-line treatment for PJP. The decision to start prophylactic treatment should be based on the individual's risk factors and medical history. Key factors to consider include:

• Immunosuppression: Patients with weakened immune systems, such as those with HIV/AIDS or taking immunosuppressive medications, are at higher risk of developing PJP.
• Increased risk: Patients with a history of PJP or other opportunistic infections, or those with certain medical conditions, such as cancer or chronic lung disease, may be at increased risk.
• Inability to tolerate TMP-SMX: Patients who cannot tolerate TMP-SMX due to adverse reactions or other reasons may require alternative prophylactic treatment, such as atovaquone 2. 2 3

From the Research

Prophylactic Treatment for Pneumocystis jirovecii Pneumonia (PJP)

• PJP prophylaxis is recommended for HIV-infected patients with a CD4 count <200 cells/mm3 or oropharyngeal candidiasis, as well as those with a CD4 percentage (CD4%) below 14% 4.
• In non-HIV-infected patients, a CD4+ lymphocyte count <200 cells/µL is the primary risk factor for PJP presentation, and trimethoprim/sulfamethoxazole (TMP/SMX) is the primary treatment and prophylaxis option 5.
• Patients with haematological malignancies are at high risk for PJP due to chemotherapy and steroid-induced immunosuppression, and prophylaxis should be widely recommended for those receiving prolonged steroid therapy or other immunosuppressive drugs 6.
• After solid organ transplantation, different risk factors for PJP have been described, and several indications for PJP prophylaxis should be considered by clinicians, even years after transplantation 7.
• In patients who have undergone CD19-targeted chimeric antigen receptor T-cell therapy, the duration of TMP/SMX prophylaxis should be determined on a case-by-case basis, considering the CD4+ T-cell count and other factors 8.

Special Considerations

• Discordance between CD4 count and CD4% occurs in 16% to 25% of HIV-infected patients, and monitoring both values is essential to guide PJP primary and secondary prophylaxis 4.
• B-cell depletion after CAR-T cell therapy may increase the risk of PJP, even in patients with a CD4+ T-cell count >200/μL, and the duration of prophylaxis should be individualized 8.
• PCR techniques and serum ß-D-Glucan analysis have become valuable diagnostic tools for PJP, but may not always discriminate between airway colonization and infection 6, 7.