Atypical pulmonary diseases associated with AIDS

HIV infection is a risk factor for venous thromboembolism

The reported incidence of venous thromboembolism (VTE) in patients with human immunodeficiency virus (HIV) infection has ranged from 0.25 to 0.96% in clinical studies, but up to 17% at autopsy. A preliminary analysis at our hospital suggested that the frequency of VTE among HIV-positive individuals might be higher than previously reported. To further evaluate this issue, we performed a retrospective study of patients with a diagnosis of VTE and/or HIV infection discharged from our hospital between July 1, 1998 and June 30, 1999. A total of 13,496 patients were discharged during the year of the study. There were 244 patients with VTE and 362 who were HIV-positive. Ten of the 244 patients with VTE were HIV-positive (4.1%). The frequency of VTE among HIV-positive individuals was 10/362 (2.8%) compared to 234/13134 (1.8%) in the non-HIV-positive group, but the difference is not statistically significant. However, in patients under age 50, the frequencies were significantly different: 10/302 (3.31%) versus 35/6594 (0.53%), respectively (p < 0.0001). The frequency of VTE in HIV-positive patients less than 50 years old (3.31%) was greater than in HIV-positive patients over 50 years of age (0/60), but the difference did not reach statistical significance. In contrast, in the non-HIV-positive group, VTE was significantly more frequent in those 50 and older compared to younger patients (3.04% versus 0.53%, p = 0.0001). Statistical analysis indicated that the direction of association between age and diagnosis of VTE differed for HIV-positive patients versus non-HIV-positive patients. Our results suggest that HIV-positive patients under age 50 are at increased risk for VTE compared with non-HIV-positive individuals.

Association between human immunodeficiency virus and osteonecrosis of the femoral head

The records of a consecutive series of 50 patients treated operatively for osteonecrosis of the femoral head were reviewed to determine the prevalence of human immunodeficiency virus (HIV) as an isolated risk factor for osteonecrosis. Twelve patients had a history of trauma to the hip and were excluded from the study. The remaining 38 patients were treated operatively for nontraumatic osteonecrosis of the femoral head. Of these, 7 patients were HIV positive, and 31 were HIV negative. Of the 7 patients who were HIV positive, 4 (57%) had none of the known risk factors for osteonecrosis. Of the 31 patients who were HIV negative, 4 (13%) had none of the known risk factors for osteonecrosis. The difference between the groups was statistically significant, suggesting that HIV infection is a risk factor for the development of osteonecrosis of the femoral head.

Clinical aspects of pulmonary embolism

Pulmonary embolism is a common disease in the United States, affecting as many as 500,000 persons annually. Unfortunately, this disorder is commonly undiagnosed, resulting in significant excess morbidity and mortality. The clinical symptoms and signs caused by pulmonary embolism are nonspecific and may be confused with a variety of other cardiopulmonary disorders having similar presentations. However, accurate diagnostic tests are available for diagnosing pulmonary embolism, even in the face of coexistent cardiopulmonary disorders. This article describes the clinical characteristics of pulmonary venous thromboembolism, reviewing its typical symptoms and signs, its routine laboratory tests, and chest radiographic abnormalities.

Cavitary pulmonary infarct in immunocompromised hosts

Pulmonary disease in immunocompromised patients is common, but cavitary lung disease is less common and is usually associated with a fungal or mycobacterial infection. Pulmonary embolism is a noninfectious cause of a cavitary pulmonary process. Pulmonary embolism causes infarction in fewer than 15% of cases, and only about 5% of infarctions cavitate. Herein we describe two cases of cavitary infarcts in immunocompromised patients and review the clinical aspects of pulmonary infarcts and cavitation. Cavitary pulmonary infarction has been reported only rarely in immunocompromised patients. It is a dangerous but treatable pulmonary disease that must be considered in the differential diagnosis of immuno-compromised patients with lung disease.