Immunological Testing
Natural Killer Cells
NK cells are lymphocytes responding mainly to viral infection and tumor formation. Over the last few decades, it was found that NK cells play an important role in pregnancy implantation however Increased activity (cytotoxicity) of those cells was associated with increased risk of recurrent pregnancy loss (repeated miscarriages) and repeated implantation failure (multiple IVF failures).
NK cells are located within the inner lining of the uterus and one of their main roles is to remodel blood vessels within the lining so they can accommodate adequate blood supply to the pregnancy. Overactivity or increased cytotoxicity of NK cells can lead to defect in implantation.
Testing the Natural killer cells is performed by a blood test (NK cytotoxicity assay) and endometrial biopsy (tissue sample from the inner lining of the uterus). Immune therapy will be decided based on the results. The blood test will be repeated multiple times during the cycle and pregnancy to make sure the NK cells activity is under control.
T-Helper 1 / T-Helper 2 Cytokines ratio
T- helper cells are lymphocytes that play an important role in regulating the immune response by secreting immune mediators (cytokines). They are called “helper” because they help or mediate the function of other immune cells. T-helper 1 to T-helper 2 ratio represents the balance between pro-inflammatory and anti-inflammatory cytokines. In a normal pregnancy, this ratio tends to decrease due to an increase in anti-inflammatory cytokines, however, in patients with repeated miscarriages or implantation failure, this ratio can be elevated.
Testing of T-helper 1 to T-helper 2 ratio is performed by flow cytometry assay. If the ratio is elevated, immune therapy will be adjusted accordingly and repeat testing will be indicated. The goal is to modulate the immune system to prevent miscarriage or implantation failure.
Antiphospholipid Antibodies
Antiphospholipid antibodies are autoantibodies that can lead to blood clotting inside the blood vessels “thrombosis” and cause repeated miscarriages and other pregnancy complications such as preeclampsia, preterm delivery, and stillbirth.
Extensive testing needed to identify those antibodies and their titers. The main treatment is blood thinners including aspirin and heparin (low molecular weight or unfractionated heparin). The patient will benefit as well from immune therapy to suppress those antibodies.