Diagnosis of pulmonary Kaposi's sarcoma by detection of human herpes virus 8 in bronchoalveolar lavage.

Human herpes virus 8 (HHV8) DNA has recently been detected in sarcoma tissue of patients with Kaposi's sarcoma. HHV8 DNA could also be found in bronchoalveolar lavage (BAL) fluid of patients with tracheobronchial Kaposi's sarcoma. To determine the specificity, sensitivity and predictive values of HHV8 DNA detection in the BAL for the diagnosis of pulmonary Kaposi's sarcoma, 100 consecutive BAL were prospectively analyzed for the presence of HHV8 DNA using a nested PCR assay. In addition, 19 BAL samples of 14 AIDS patients with cutaneous or visceral Kaposi's sarcoma were retrospectively investigated. The prospective group consisted of 79 BAL performed in immunocompromised and of 21 BAL in nonimmunocompromised patients. Four patients of the prospectively analyzed group undergoing six BAL showed tracheobronchial Kaposi's sarcoma at five bronchoscopies. All of the five BAL samples performed in these patients with endoscopically visible Kaposi's sarcoma were positive for HHV8 DNA. Following chemotherapy and antiretroviral treatment tracheobronchial Kaposi's sarcoma was no longer detectable at a subsequent bronchoscopy and HHV8 DNA in BAL became negative in one patient. One BAL sample of a HIV-positive patient with no evidence of Kaposi's sarcoma was HHV8 DNA-positive. The sensitivity, specificity, positive and negative predictive values of HHV8 detection for the diagnosis of tracheobronchial Kaposi's sarcoma were 100%, 98.9%, 83.3%, and 100%, respectively. Twelve of 19 BAL samples of the retrospective group were HHV8 DNA-positive. In this group, 10 patients undergoing a total of 14 BAL suffered from pulmonary Kaposi's sarcoma. HHV8 DNA was documented in 10 of these 14 BAL samples. In three BAL of this group HHV8 DNA was positive, but pulmonary Kaposi's sarcoma was diagnosed at a later stage. In conclusion, the detection of HHV8 DNA in BAL is restricted to patients with Kaposi's sarcoma and is highly sensitive and specific for pulmonary involvement of Kaposi's sarcoma.