common opportunistic infections and tumours if HIV and low CD4 count

Last edited 03/2018

opportunistic infections and tumours

Patients with a CD4 count of <200x10^6/litre are susceptible to infections by pathogens which would not normally cause disease in an immunocompetent individual.
Common opportunistic infections are:

• pneumocystis carinii pneumonia
• cerebral toxoplasmosis
• oesophageal candidiasis
• diarrhoea, pathogens including:
  • cryptosporidium
• CMV
• atypical mycobacteria

Common malignant diseases includes:

• Kaposi's sarcoma
  • the most common tumour in people with HIV infection
• is an AIDS-defining illness and is caused by the Kaposi sarcoma herpesvirus (KSHV).

• high-grade B cell non-Hodgkin's lymphoma
  • two commonest subtypes are diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma/leukaemia (BL)
• both are considered as AIDS-defining illnesses (ADI).
• is the second most common tumour in individuals with HIV
• studies have indicated a decline in incidence since the introduction of HAART
• development of AIDS-related lymphomas (ARLs) has been shown to be related to older age, low CD4 cell count and no prior treatment with HAART

• cervical carcinoma
  • almost all cases of invasive cancer are associated with infection with oncogenic types of human papilloma virus (HPV), particularly HPV 16 and 18
• women with HIV infection are more likely to have infection with HPV 16 or 18 than women who are HIV negative
• Invasive cancer is preceded by cervical intraepithelial neoplasia (CIN) which has a higher prevalence and incidence in women with HIV infection (1)

Note:

• all patients with HIV and malignancy should be referred to centres that have developed expertise in the management of these diseases
• most serious problems usually occur at very low CD4 counts (below 100 cells/μl) so other clinical clues to immunosuppression are likely to be present.
• Pneumocystis pneumonia (PCP) is an exception to this rule as it tends to occur at higher CD4 counts (below 200).
• it may be the first HIV-related problem for which the patient seeks advice
• the prognosis correlates directly with how early or late the infection is identified and treated: PCP can kill if diagnosed too late (2)

Reference:

• (1) Bower M et al. British HIV Association guidelines for HIV-associated malignancies 2014. HIV Med. 2014;15 Suppl 2:1-92.
• (2) The Medical Foundation for AIDS & Sexual Health (MedFASH) 2016. HIV in primary care. A practical guide for primary healthcare professionals in Europe.

clinical indicator diseases for adult HIV infection

Reference:

• (1) British HIV Association British Association of Sexual Health and HIV British Infection Society. UK National Guidelines for HIV Testing 2008.