From the Guidelines
A patient with HIV and a CD4 count of 175 cells/mm³ is at increased risk of developing opportunistic infections and certain malignancies due to their compromised immune system. These include Pneumocystis pneumonia (PCP), toxoplasmosis, cryptococcal meningitis, tuberculosis, histoplasmosis, and progressive multifocal leukoencephalopathy (PML) as noted in patients with low CD4 counts 1. Malignancies such as Kaposi's sarcoma, non-Hodgkin lymphoma, and cervical cancer are also more common in this population. The patient's increased risk is not only due to immunosuppression but also due to uncontrolled viral replication causing immune activation and inflammation, which may increase the long-term risk of complications such as coronary heart disease, stroke, neurocognitive impairment, malignancies, and osteoporosis 1.
Key Considerations
- The patient requires prophylaxis against PCP with trimethoprim-sulfamethoxazole (one double-strength tablet daily), and if toxoplasma IgG positive, this medication also provides toxoplasmosis prophylaxis.
- Antiretroviral therapy (ART) should be initiated immediately to increase CD4 counts and reduce viral load, which will significantly decrease the risk of these complications.
- The patient should also receive appropriate vaccinations and undergo regular screening for tuberculosis and cervical cancer (if applicable).
Management Approach
- The comprehensive approach is necessary because CD4 counts below 200 cells/mm³ represent significant immunosuppression, making the patient vulnerable to infections that typically wouldn't affect those with intact immune systems.
- Geographic considerations should also be taken into account in the differential diagnosis of pulmonary disorders in immunocompromised patients, such as the intersection of the AIDS epidemic with endemic tuberculosis in certain regions 1. Initiating ART immediately and providing prophylaxis against opportunistic infections are crucial steps in managing this patient's condition and reducing the risk of morbidity and mortality. This approach is supported by the evidence that ART reduces morbidity and mortality in HIV-infected individuals, and that universal testing and immediate treatment of HIV-infected patients could reduce or even end the epidemic 1.
From the Research
Conditions Associated with HIV and Low CD4 Count
Patients with Human Immunodeficiency Virus (HIV) and a CD4 count of 175 are at increased risk of developing various opportunistic infections, including:
- Pneumocystis jirovecii pneumonia (PCP) 2, 3, 4, 5
- Toxoplasmosis 2, 6
- Mycobacterium avium complex (MAC) disease 2, 6
- Cryptococcosis 3, 6
- Cytomegalovirus (CMV) disease 2, 6
- Herpes simplex virus (HSV) 2
- Varicella zoster virus (VZV) 2
- Invasive fungal disease 2
- Tuberculosis 2
Risk Factors and Mortality
The risk of developing these opportunistic infections is increased in patients with low CD4 counts, and mortality is higher in patients with advanced age, low CD4+ cell count, and being underweight 3, 6. The occurrence of opportunistic diseases is significantly associated with death, independently of CD4 cell count 6.
Treatment and Prophylaxis
Trimethoprim-sulfamethoxazole is the first-line agent for treatment and prophylaxis of PCP 4, 5. Alternative treatment regimens include dapsone with trimethoprim, clindamycin with primaquine, atovaquone, or pentamidine 5. Prophylaxis against opportunistic pathogens is effective and depends on the immune status of the patient and the underlying immunocompromising disease 2, 5.