[Silicoproteinosis: a specific clinical and radiological entity]. / La silicoprotéinose : une entité radioclinique à part.

INTRODUCTION: Silicoproteinosis is a rare disease, which can cause the rapid onset of respiratory failure following massive exposure to silica dust. CASE REPORT: A 25-year-old patient presented with altered state and dyspnea. The diagnosis of military pulmonary tuberculosis was first considered and antituberculous treatment was started. The diagnosis was reconsidered due to a lack of improvement and the discovery of an 18-month history of exposure to silica. The patient had stopped work 6 months prior to hospitalization. High-resolution CT showed air space condensation associated to centrilobular nodules throughout the lungs and multiple mediastinal lymph nodes, suggesting sarcoidosis. Bronchoalveolar lavage (BAL) suggested the diagnosis of lipoproteinosis. Because of discordance between the bacteriological, radiological and the BAL results, a surgical lung biopsy was performed which led to the diagnoses of a secondary lipoproteinosis. The diagnosis of silicoproteinosis was then considered. Over a one-year follow up, the patient's respiratory failure has progressed markedly despite treatment with corticosteroids. CONCLUSION: Silicoproteinosis is a distinct pathological entity, the diagnosis of which depends on clinical and radiological features as well as BAL findings, which may avoid the need for more invasive investigations.

[Study on drug-resistance of Mycobacterium tuberculosis isolated from coal workers with silico-tuberculosis].

OBJECTIVE: To study the gene mutation and streptomycin, isoniazid or rifampicin resistance of Mycobacterium isolated from silico-tuberculosis patient's sputum so as to find a more effective therapy for this disease. METHODS: Mycobacteria tuberculosis were separated from 96 coal worker with silico-tuberculosis firstly. Then rpsL, KatG and rpoB fragments of genome were copied with PCR and compared their SSCP profiles with standard strains. RESULTS: 67 strains of streptomycin, isoniazid or rifampicin resistant Mycobacteria tuberculosis were found in routine drug resistance test, with the percentages of 80.5% (54/67), 58.2% (39/67) respectively. PCR-SSCP showed that out of 67 drug-resistant strains, 66(98.5%) of rpsL, 47(70.1%) of rpoB and 42(62.7%) of KatG appeared abnormal. CONCLUSION: Most of the resistant strains appeared gene mutation. The mution rates were higher than the results from routine drug resistance test.

[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.

A controlled clinical comparison of 6 and 8 months of antituberculosis chemotherapy in the treatment of patients with silicotuberculosis in Hong Kong. Hong Kong Chest Service/tuberculosis Research Centre, Madras/British Medical Research Council.

Patients with silicotuberculosis have been reported to respond poorly to antituberculosis chemotherapy. Therefore, in a study in Hong Kong, 240 Chinese male patients with both silicosis and pulmonary tuberculosis were all prescribed treatment three times weekly with streptomycin, isoniazid, rifampin, and pyrazinamide, allocated at random to be given for a total duration of either 6 (M6 regimen) or 8 months (M8 regimen) in a concurrent comparison. Those with a history of previous antituberculosis chemotherapy received ethambutol as well for the first 3 months. The intake in the M6 regimen was terminated when preliminary results showed that it was inadequate, and a further 53 patients were assigned to the M8 series. Of 91 assessable patients in the concurrent comparison with susceptible strains pretreatment, 44% were culture negative at 1 month, 80% at 2 months, and 98% at 3 months, and 1 had an unfavorable bacteriologic response during chemotherapy. During 3 yr of assessment, bacteriologic relapse after chemotherapy occurred in 22% of the M6 compared with 7% of the M8 patients (p less than 0.025, log-rank test). Inadequate chemotherapy was received by 12% of the 240 patients in the concurrent comparison because of default and by 22% because of adverse effects, but by 3 yr 92% of patients with susceptible strains pretreatment in each series had a favorable status following retreatment for relapse or for initially inadequate chemotherapy when required. The results show that patients with silicosis require at least 8 months of treatment.

[Results of intermittent biweekly treatment with rifampicin and ethambutol in silicotuberculosis]. / Rezultatele tratamentului bisaptamînal intermitent cu rifampicina si etambutol în silicotuberculoza.

The results were analysed, of the results obtained by the associated treatment with rifampicin and etambutol 2/7 for at least 6 months in 53 patients with silico-tuberculosis and positive bacteriologic tests. Only two of the patients in the group were in the 1-st stage of silicosis while half of the patients had cavities. Also 50% of the patients had strains showing resistance to various drugs. Only five of the patients did not receive chemotherapy before the start of the study. Immediate favourable bacteriological results were noted in 84.9% of the cases and late positive results represented 54.7%, while radiologic improvement was noted in 33.9% of the cases. The percentage of good results was higher in patients without cavities but it was not influenced by the stage of silicosis development.