[Mycobacterium tuberculosis L forms in patients with pulmonary silicotuberculosis and silicosis].
OBJECTIVE
To evaluate significance of Mycobacterium tuberculosis L forms in pathogenesis of silicotuberculosis and silicosis.


METHODS
Sputum culture for Mycobacterium tuberculosis and its L forms was conducted from both silicotuberculosis and silicosis groups, and the results were compared.


RESULTS
Among 60 silicotuberculosis patients, 6 (10%) were sputum Mycobacterium tuberculosis culture positive, of which 5 (83%) were Mycobacterium tuberculosis L forms culture positive; 28 were sputum Mycobacterium tuberculosis L forms culture positive (positive rates in the patients with silicosis stage I, stage II, stage III were 33%, 67%, 100% respectively), with a positive rate of 47%, and a significant difference was found comparing with the frequency of detecting Mycobacterium tuberculosis (P < 0.01). All of the 30 cases with silicosis were Mycobacterium tuberculosis culture negative, however, 3 of them were sputum Mycobacterium tuberculosis L forms culture positive, accounting for 10 percent.


CONCLUSIONS
Sputum culture for Mycobacterium tuberculosis L forms is a convenient and rapid way to improve the detection rate of Mycobacterium tuberculosis, with a positive value in early diagnosis of silicotuberculosis by reducing misdiagnosis and underdiagnosis of this disease. Detection rate of Mycobacterium tuberculosis L forms significantly increases with deterioration of silicosis.
Zhu
C
C
Tongling Nonferrous Shicheng Hospital, Anhui Province, Tongling 244000, China.
Xie
S
S
Zhang
J
J
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification / Q000502:physiology*; D012829:Silicosis / Q000382:microbiology*; D012830:Silicotuberculosis / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology