[16612479]
Three hiv-infected pts seen in rptr's institution with abnormal chest radiographs and fluorochrome stain-positve sputum were evaluated for tuberculosis, including performance of the test on expectorated sputum samples. Two of three pts' sputa were highly smear-positive (i. E. >100 bacilli/high power field), while the third pt's sputum contained 6-10 bacilli/hpf. Results on the initial specimens from these pts ranged from 43,498 to 193,858 rlu. Mfr defines values >_ 30,000 rlu as indicative of positive test, i. E. , the presence of m. Tuberculosis rna. All three pts' sputum cultures yielded growth of m. Kansasii within 6-12 days. One pt's culture also contained m. Avium, but none of the initial or follow-up cultures from the pts revealed m. Tuberculosis. However, subsequent cultures from all three pts again revealed m. Kansasii. Other sputum specimens from two of the pts that had only 1+ or 2+ smear positivity were test-negative in 2/3 instances. A fourth pt with 1+ smear positive sputum due to m. Kansasii yielded a negative test. Five cultures of m. Kansasii (including these 4 pts' isolate and cultures of several other species were examined at densities of test. All five isolates of m. Kansasii and 3/3 isolates of m. Simiae yielded false-positive tests with rlu values of 75,191 to 335,591. These results indicate that low-level false-positive results can occur due to m. Kansasii and possibly other mycobacterium species in sputum. Rlu values of 30,000-400,000 should be interpreted with caution. Add'l pts's ages: 40, 44. Add'l dates of event: 4/4/96, 4/5/96.
Patient Sequence No: 1, Text Type: D, B5