Th1 Th2 Assay

The TH1 (T Helper 1) and TH2 (T Helper 2) Intracellular Cytokine Assay

White blood can be separated into a number of different cell types determined by characteristics that can be visualized under the microscope.  One of these cell types is known as the lymphocyte. The lymphocyte is one of the primary cells of the immune cell being involved at many stages of immune response.  We have come to understand that there are very many types of lymphocytes.  However, the differences between them are too subtle to distinguish when we view them under the microscope.   In the 1980′s antibodies that react with surface proteins unique to various types of lymphocytes became available.  With this development, it became possible to study the different types of lymphocytes and observe their different behavior.  One of these lymphocytes was known as the “T cell”.  Within this group of lymphocytes, a further distinction was made.  Cells were found that secrete hormone-like substances known as ”cytokines”  that profoundly affecting the responses of other immune cells in the surrounding area.  These “conductor” cells became known as “T helper cells”.  These lymphocytes were subdivided.  T helper cells found to secrete cytokines that directed immune cells to attack target cells that might be infected or recognized as abnormal became known as Th1 cells.  Other T helper cells found to secrete a variety of cytokines that tend to oppose the cytokines secreted by Th1 cells became known as Th2 cells.

In the 1990′s a theory was advanced that was supported by substantial clinical and laboratory suggested that the balance between Th1 and Th2 cells was important in women suffering recurrent reproductive failure.  Women who had higher ratios often had higher levels of infertility and pregnancy loss.  Because there are therapies that modulate the Th1/Th2 ratio in these women improve their reproductive outcomes, testing for the ratio is performed on patients in our program.

The test performed in the laboratory involves stimulating T helper cells so that they produce the cytokines that indicate whether they are Th1 type cells or Th2 type cells.  The cells are then reacted with antibodies that detect these cytokines.  The cells of each type are then counted in a special laboratory instrument found only in specialized immunology laboratories known as a flow cytometer. This instrument is capable of reporting the numbers of each type of cell. Patients with elevated ratios can then be treated with a number of different drug programs determined by the treating physician. Patients who need additional information should Contact us.


1. Kwak-Kim JY, Chung-Bang HS, Ng SC, Ntrivalas EI, Mangubat CP, Beaman KD, Beer AE, Gilman-Sachs A. Increased T helper 1 cytokine responses by circulating T cells are present in women with recurrent pregnancy losses and in infertile women with multiple implantation failures after IVF. Human Reproduction. 2003 Apr;18(4):767-73.

2. Winger EE, Reed JL, Ashoush S, Sapna A, El-Toukhy T, Taranissi M: “Treatment with adalimumab (Humira) and intravenous immunoglobulin (IVIG) improves pregnancy rates in women undergoing IVF. American Journal of Reproductive Immunology, 2009; 61:113-120.