Elevated soluble CD26 levels in patients with tuberculous pleurisy.
METHODS
Several reports have shown that tuberculous infection elicits a Th1-like immune response with increased levels of IFN-gamma. Recently, expression of CD26 on CD4+ lymphocytes has been shown to correlate with the production of Th1-like cytokines. We therefore hypothesized that CD26 expression might increase in tuberculous pleural effusion, and might thus be a possible marker for detecting tuberculous pleurisy.


OBJECTIVE
To test this hypothesis, we measured soluble CD26 levels in the serum and pleural fluid of patients with tuberculous pleurisy (TB; n = 13), carcinomatous pleurisy (CA, n = 17), empyema (EM, n = 6), and congestive heart failure (HF, n = 10).


RESULTS
The pleural CD26 levels, but not the serum CD26 levels, in patients with tuberculous pleurisy were significantly higher than those in other groups, and were correlated with levels of adenosine deaminase and interferon-gamma in the tuberculous pleural effusion. Furthermore, when the cut-off value for p-CD26 was set at 544.5 ng/ml, the positive rate for the TB group was significantly higher than that for the CA, EM and HF groups (P < 0.05).


CONCLUSIONS
These results suggest that elevation of soluble CD26 in pleural fluid is implicated in Th1-like immune response, and may be a useful marker for tuberculous pleurisy.
Oshikawa
K
K
Department of Pulmonary Medicine, Jichi Medical School, Minamikawachi, Tochigi, Japan. oshikatu@jichi.ac.jp
Sugiyama
Y
Y
D000243:Adenosine Deaminase / Q000032:analysis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D018819:Dipeptidyl Peptidase 4 / Q000032:analysis* / Q000276:immunology; D016724:Empyema, Pleural / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006333:Heart Failure / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000276:immunology / Q000378:metabolism; D016066:Pleural Effusion, Malignant / Q000276:immunology / Q000378:metabolism; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000276:immunology / Q000378:metabolism*
D015847:Interleukin-4; D007371:Interferon-gamma; D018819:Dipeptidyl Peptidase 4; D000243:Adenosine Deaminase