Pathology of human immunodeficiency virus infection: infectious conditions.

Infection with the human immunodeficiency virus (HIV) and the subsequent derangement of host immunity place affected patients at risk for secondary infections. Some of the secondary pathogens occur with such frequency or are so rare in the non-immunosuppressed population that they have become part of the Centers for Disease Control and Prevention (CDC) classification for HIV/acquired immune deficiency syndrome (AIDS). Other infectious agents not yet included in the CDC definition are being reported in the HIV-infected population with increased frequency. General observations of the degree of immunosuppression associated with specific secondary infections have been useful in developing classification systems for HIV disease such as that of the CDC. However, the specific alterations in host immunity that promote infection with specific secondary pathogens are generally unknown. Geographic differences in the types and frequency of secondary infections also have been reported. Variation in strains of HIV, effect of malnutrition, lack of appropriate medical treatment, prevalence of virulent infectious diseases, and epidemiologic differences are possible contributing factors. Some infections that seemed likely to be closely associated with HIV infection have not occurred more frequently in HIV-infected patients. This review summarizes the histopathology of infectious conditions in the current CDC classification and highlights some conditions seen in HIV-infected individuals that are not currently HIV/AIDS-defining infections, yet may be seen by practicing pathologists.

Pathology of human immunodeficiency virus infection: noninfectious conditions.

Diagnostic anatomic pathologists play a crucial role in the battle against acquired immunodeficiency syndrome (AIDS). Not only are they intimately involved in the treatment of individual patients with human immunodeficiency virus (HIV) infection, but also they make important observations that result in the expansion of the scientific understanding of its pathogenesis. Pathologists studying tissue from patients with HIV infection should be familiar with the conditions to which these patients are susceptible. Although opportunistic infections are important causes of morbidity and mortality, noninfectious conditions frequently make substantial contributions to the disease course. Patients with HIV infection may be at increased risk for neoplastic disease. They do not, however, have an increased incidence of the most common tumors affecting the general population, such as breast, colon, and prostate carcinoma. Immunodeficiency results in increased susceptibility to malignant neoplasms, both by decreased immunologic response to abnormal cells and increased susceptibility to infection by viruses. All of the malignant neoplastic diseases that are Centers for Disease Control and Prevention (CDC) AIDS indicator conditions have been shown to have an association with a virus: Kaposi sarcoma (KS) with herpes hominis virus 8 (HHV-8), malignant lymphoma with Epstein-Barr virus (EBV), and cervical carcinoma with human papilloma virus (HPV). Patients with HIV infection also can develop reactive processes that are attributable to direct effects of HIV or immune system alterations. Such conditions include salivary gland cystic lymphoepithelial lesion, lymphadenopathy, lymphocytic interstitial pneumonitis, encephalopathy, enteropathy, nephropathy, hepatic conditions, dermatologic conditions and anemia.

Recent advances in the pulmonary pathology of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS).

Pathology played an important role in the initial recognition of AIDS and continues to be instrumental in the development of case definitions and in the diagnosis of indicator conditions of HIV. This chapter provides an update on HIV and AIDS and discusses the pathologic evaluation of various respiratory conditions in the HIV-infected patient.

Group B streptococcal meningitis presenting as stroke in a nondebilitated man.

An unusual case of group B streptococcal meningitis in an adult is described. The evidence presented suggests that early vascular involvement during the meningitic process resulted in cerebral infarction, thereby explaining the patient's sudden deterioration and atypical presentation.