Research On Value Of IFN-γ And IL-2 In Diagnosing Tuberculous Pleurisy

Tuberculosis is a severe epidemic disease that endanger thehuman's health. China is one out of 22 countries in the world thatsuffers the high rate of such infection, only next to India, rankingNo. 2 in the world. The rate of infection for tuberculosis in theyear 200 is 44.5% while the rate of infection for bacillus being0.72%, among these infected crowds, 10% of which will infecttuberculosis later, the tuberculous pleurisy, a special type oftuberculosis, is tending to increase, the domestic reo9rt in 1980sindicate that the percent of tuberculosis patients keep 3.2-7.0%out of the whole patients, this percentage increased to 10.9% in1990s. There are many similarities in prevention and control oftuberculous pleurisy and phthisic, therefore, gnosia and the intime diagnosis and treatment for tuberculous pleurisy plays animportant position. Clinically there many elements that can cause chest wateraccumulation, such as connective tissue diseases, abnormalpathological changes and malignancy etc., of which, thetuberculous pleurisy and malignant pleura disease occupy themajority, the distinction between these two diseases had beenharassing the respiratory doctors for years. Along with themedical development, the method for chest water accumulationdiagnose is progressing, including chest water pathogeny check,pleura biopsy and chest mirror check, the first check usuallygives a low masculine rate, the second and the third one arethaumatic check which is sometimes unacceptable to the patients.The biochemical index check for chest water attach dueimportance to the tuberculous pleurisy diagnoses, for example,the ADA>45U/L value has a higher accuracy in diagnosingtuberculous pleurisy, but it is affected by the masculine rate andtheir peculiarities.Along with the development of cell biology and molecularbiology, the scholars from both domestic and foreign countriesreach a fairly uniform conclusion, namely, partial immuneenhancement property of tuberculous pleurisy is indicated by thehigh content of various cell genes in tuberculous chest water,somebody suggest that this high content property will provide anew solution to the tuberculous pleurisy diagnoses anddistinction.In order to verify the partial immune enhancement propertyin tuberculous pleurisy, discuss the value of cytokine intuberculous pleurisy diagnose and distinction, three test sampleswere selected, i.e. tuberculous pleurisy group (I), malignant chestwater group (II), and health group (III), Double AntibodyEnzyme Chain Immune Absorption Method was introduced toobserve the serum and IFN-γ and IL-2 in diagnosing thetuberculous pleurisy, The research result indicate that the IFN-γand IL-2 level in tuberculous chest water are obviously higherthat the serum around them (p<0.01), the p/s value are 8-20 timesand 2-18 times respectively. The concentration of two kinds ofcytokines in serum in group I and group II have no obviousdifference in comparison with the health group (p>0.05), the levelof two kinds of cytokines in chest water of group II is slightlyhigher, but is has no obvious difference with its serum content(p>0.05), supporting the viewpoint of partial immuneenhancement at tuberculous pleurisy, meanwhile, the level ofIFN-γ and IL-2 in tuberculous chest water also obviously higherthan those of the malignant chest water (p<0.01), therefore theoptimum critical value of diagnosing tuberculous pleurisy withIFN-γ is 145.9pg/ml, the sensitivity being 92.5%, peculiaritybeing 100%, accuracy index being 0.93, this indicates that theIFN-γ has a perfect effectiveness in diagnosing tuberculouspleurisy, the optimum critical value of diagnosing tuberculouspleurisy with IL-2 is 63.59pg/ml, sensitivity being 60%,peculiarity being 97.5%, accuracy index being 0.58, though thesensitivity and accuracy index are lower than those of IFN-γ, thepeculiarity is higher which can also be of help in diagnosing thetuberculous pleurisy.The high content of cytokines in tuberculous chest waterindicate the speciality of its immune system, many scholars haveconducted researches on relations between the maladjustment ofTh1/Th2 under T cell group of CD4 and tuberculosis, thoughthere are some disputes on the content of Th 2 under differentperiod of tuberculosis, the majority of scholars have accepted theidea that the low immune reply of Th1 cell is the property oftuberculosis, however, Barnes questioned whether the serumaround the tuberculosis can truly reflect the changes in the body.The research shows the partial immune of buberculous pleurisy isenhanced and it is considered that the immune reply ofpathological changes is mainly guided by TH1 cell. This researchobserved the content of the two representative cytokine IFN-γ andIL-2 in TH1 cell in chest water and serum. The same conclusionwas made. The previous viewpoint emphasize on the idea thattuberculous pleurisy is caused by the later discovered abnormalchanges, resulting in pleuro capillary vessel effusion, thecorporeal element and water leak out from blood to the breast,thus causing chest water. The modern viewpoint think thetuberculous pleurisy is caused by the invasion of tuberculousbacteria to pleuro, the elements in the bacteria may cause partialor systemic immune reply. the test shows that both laterdiscovered abnormal changes and bacteria invaded tuberculouspleurisy have the same properties, namely, the partial reflection isobviously bigger than the systemic reflection. The reason thatthe two kinds of cytokines in malignant chest water are notobviously increased may relate to tumor exudation immunerestrain genes and tumor immune evasion system.IFN-γ is a kind of cell gene exudated by T cell and NK cell,at present it is know as an indulged cytokine, that can regulateimmunity of various cells, particularly in the process of activityof monocyte, it is proved to be an important cytokine, and hasobvious anti infection and anti tumor function. Generally, IFN-γincrease in tuberculous chest water is caused by T lymphocyte,especially CD4+ cell under stimulation from bacilli, theresearchers have conducted more studies on IFN-γ , it wasreported that sensitivity and peculiarity of IFN-γ cell gene indiagnosing tuberculous pleurisy is 100%. This research isapproximately correspond to the previous report, the optimumcritical value is a little bit low, this may relate to the option ofpatients and samples.IL-2 is a kind of lymph activated gene, which has relationswith systemic anti-tumor and anti virus functions, that can beproduced through split pathogen stimulating CD4+T and CD8+Tand T cell hybridized tumor, It plays a key function in variousimmune cells and lymph genes. IL-2 and IFN-γ have coordinativefunctions, IL-2 can stimulate T cell to release more IFN-γ, butdisputes exit in diagnosing value of IL-2 in tuberculous pleurisy,somebody insists that the tuberculous chest water is overlappedwith malignant chest water, approximately 72% (10/14) of thetwo are similar. This research shows that 40% of tuberculouschest water is similar to that of malignant chest water, the surfaceunder ROC curveline is 0.81 (>0.5), the sensitivity is notfavorable but its peculiarity is higher, which indicates the higherpossibilities of effusion and lower misdiagnoses. In general, IL-2still plays an important role in diagnosing tuberculous pleurisy.