Abstract: Objective To evaluate the diagnostic value of 4 kinds of Methods combination used for primary smear and culture negative pulmonary tuberculosis.Methods The 4 testing Methods were PCR ELISA exa mination for sputum;TB DNA, MycoDot method for serum LAM IgG,sandwich ELISA method for serum;sIL 2R and PPD 1TU skin test.4 testing Methods were used individ ually and in combination manner respectively to 57 smear and culture positive cases,58 smear and culture negative cases,41 non tuberculosis respiratory patients and 36 healthy people in control group.Results The positive detection rate of single test by PCR ELIS A,LAM IgG,PPD and sIL 2R for sputum TB negative patients was 43.1% ,37.9%,31.0%,50.0% respectively. In combination examination the positive rates increased remarkblely by the number combined from 2 to 4, they were 56.9%,70.7%,84.5% respectively,and the specificity was 92.2% ,88.3%,88.4% ,remain a higher specificity.Conclusion Using the 4 kinds of Methods to diagnose primary smear and culture negative pulmonary tuberculosis patients can increase the positive rates of detection obviously and remain a higher specificity. It is val uable for widely use of combination method in detection of primary smear and cul ture negative tuberculosis patients.

Key words: Pulmonary tuberculosis/diagnosis, Polymerase chain re action enzyme Linked immunosorbent assay, Lipoarabinomannan, Tuberculin test, solu ble Interleukin 2 receptor