Men's Health Special: Detailed Explanation of Multi-Organ and Multi-System Damage Caused by HIV

Specific Manifestations of Multi-Organ and Multi-System Damage

① Hematologic System: Changes in this system occur relatively early, often before the diagnostic criteria for AIDS are met. Five cases of leukopenia, thrombocytopenia, and pancytopenia have been reported, four of whom presented with low-grade fever, purpura, and lymphadenopathy. Literature reports immunological examinations reveal: decreased absolute peripheral blood lymphocyte count, T4/T8 <1; abnormal B cell function, showing polyclonal B cell activation, possibly related to increased circulating immune complexes; elevated IgA, IgE, IgG, and IgM; autoantibody formation; bone marrow morphology and biopsy showing bone marrow necrosis and fibrosis; and phagocytosis of erythrocytes, leukocytes, and platelets by histiocytes. In cases complicated by persistent generalized lymphadenopathy, histological changes can be classified into proliferative and degenerative types. The proliferative type is characterized by germinal center proliferation, with or without destruction and increased angiogenesis, and increased postcapillary venules in the paracortical area. The degenerative type is characterized by follicular degeneration and reduction, with or without fibrosis. Immunohistochemistry shows T4 and T8 lymphocyte infiltration and progressive lysis of follicular dendritic cells in the germinal centers. HIV antigens are detected in the reticular structures of the germinal centers, similar to follicular dendritic cells, in the endothelial cells of the microvessels in the paracortical area, and in the lymphatic sinus macrophages.

② Nervous System: The clinical incidence of nervous system damage is 30%–40%, and the autopsy detection rate is 70%–80%. Manifestations include acute HIV meningitis, subacute encephalitis, toxoplasmosis, cryptococcal meningitis, primary cerebral lymphoma, cerebrovascular diseases (hemorrhage, embolism, etc.), myelitis, and peripheral neuropathy. Subacute encephalitis is a major cause of progressive dementia in AIDS patients, with brain atrophy as its basic pathological change. Reports indicate an incidence rate of 36%–50% in AIDS patients and 70%–90% in those with central nervous system damage over a 3-year observation period. Its occurrence is believed to be related to CMV infection. Typical cases have an insidious onset, gradually worsening, with early manifestations including personality changes, memory loss, difficulty explaining problems, intellectual decline, slow thinking, sluggish reactions, fatigue, and loss of libido. Some patients present with severe depression, anxiety, and paranoid psychosis. Others report symptoms of peripheral neuropathy such as headache, distal sensory impairment, and motor disorders. Some also present with hemianopsia, dysarthria, positive pyramidal tract signs or extrapyramidal signs, and approximately 30% of patients have myoclonus; some also present with paroxysmal epileptic-like seizures. Electroencephalography (EEG) may show slow alpha waves, MRI may show typical images of subacute encephalitis, while CT scans may show no obvious abnormalities. Other neurological lesions have been described in the section on opportunistic infections. ③ Gastrointestinal tract: The incidence of lesions is 50%–70%. Gastrointestinal infections occurring in high-risk groups for HIV are a susceptibility factor for HIV and may synergistically participate in the pathogenesis of AIDS. This is based on epidemiological data showing a high incidence of intestinal amebiasis, giardiasis, hepatitis, and bacillary dysentery among individuals with promiscuous sexual relationships or engaging in high-risk sexual behaviors such as anal or oral sex. Gastrointestinal infections disrupt the mucosal barrier, facilitating HIV invasion; there have been reports of hypoacidity associated with opportunistic intestinal infections; and there are also reports of CMV and HSV causing infectious esophagitis. Diarrhea leads to malabsorption of exogenous nutrients and excessive loss of endogenous nutrients. Intestinal wall damage facilitates the entry of microbial antigens, food antigens, and antigens from normally excreted toxic waste into the body, causing antigen overload and excessive antibody production, leading to allergic reactions and inflammatory bowel disease. Laboratory tests may show changes in T cell subsets and immune complex deposition. Given the above, the intestinal manifestations of high-risk groups, HIV-infected individuals, and AIDS patients should be given full attention and treated promptly.

Diarrhea is one of the main manifestations of AIDS. Especially in developing countries and tropical regions, the incidence of diarrhea among AIDS patients can be as high as 90%, mainly falling into the following types: Small intestinal diarrhea, characterized by watery stools, primarily seen in those complicated by Giardia lamblia and Cryptosporidium infections. Colonic diarrhea, characterized by mucus-foamy or bloody stools, primarily seen in those complicated by amebic enteropathy, bacterial dysentery, cytomegalovirus enteritis, and inflammatory bowel disease. Mycobacterium avium infection, with lesions mostly in the small intestine and rectum, presents with fever, diarrhea, and weight loss; some cases may present as Whipple's syndrome, more common in men, presenting as intermittent diarrhea with frothy, copious, foul-smelling stools; occasionally, migratory joint pain and purpura; lymphadenopathy and serositis are also common; symptoms can be relieved by anti-tuberculosis drugs and corticosteroids. Nonspecific proctitis associated with HIV infection in male homosexuals. Fungal intestinal inflammation; frequent diarrhea, stools often greenish-yellow, mucous-gelatinous, fungi can be found in smears or cultures; antifungal treatment can temporarily relieve symptoms.

Hepatomegaly and splenomegaly: related to the following factors: hepatitis virus infection, with an infection rate as high as 76%–95% in AIDS patients, frequently resulting in chronic persistent hepatitis, chronic active hepatitis, and cirrhosis. Kaposi's sarcoma can also invade the liver, with an incidence of about 44%, presenting with fever, hepatomegaly and splenomegaly, and vascular nodules in the liver. Lymphoma; AIDS-related lymphomas mainly invade extralymphatic tissues, causing multi-organ damage including the liver, presenting with fever, hepatomegaly, mostly B-cell origin, and high malignancy. Hepatic avian mycobacterium infection: presenting with fever, hepatomegaly, and elevated alkaline phosphatase; combined treatment with anti-tuberculosis drugs and chlorpheniramine has some effect. Liver cancer is mainly hepatocellular, followed by cholangiocellular and mixed types. Based on clinical manifestations, it is classified into simple type (progressive hepatomegaly, pain in the liver area, hardened liver, which may be nodular or massive), inflammatory type (fever, hepatomegaly, tenderness in the liver area, resembling liver abscess, often seen in cases of liquefied tumors or secondary infections), and cirrhotic type (manifested as diffuse liver dysfunction and portal hypertension, often occurring in patients with cirrhosis).