Immune Testing

Reproductive immunological tests

There are several tests that can be used in reproductive immunology to diagnose and manage autoimmune disorders, hormonal imbalances, and other conditions that can affect fertility.

Reproductive immunology testing refers to a series of tests that are used to assess the immune system’s role in infertility and pregnancy complications. These tests are typically performed when there is a history of recurrent miscarriage, failed IVF cycles, or unexplained infertility, and can provide valuable information about the underlying causes of these issues.

The immune system plays a critical role in reproductive health, and any disruption in its normal functioning can have significant implications for fertility and pregnancy outcomes. Reproductive immunology testing can help to identify immune system abnormalities, such as autoimmune disorders or the presence of anti-sperm or anti-embryo antibodies, that may be contributing to infertility or recurrent pregnancy loss.

Some of the most common reproductive immunology tests include Natural killer (NK) cell assays, Antiphospholipid antibody testing, Anti-thyroid antibody testing and HLA typing.

Immunological testing can help to identify immune system abnormalities that may be contributing to infertility or pregnancy complications, and can guide the development of targeted treatment strategies to improve outcomes.

Immunological assessment

Most common tests for the diagnosis and management of reproductive disorders related to the immune system

Antinuclear antibody (ANA) test

This test measures the presence of antibodies that attack the nuclei of cells in the body. ANA antibodies are commonly found in people with autoimmune disorders, such as systemic lupus erythematosus (SLE). ANA testing can be helpful in diagnosing autoimmune disorders that can cause infertility.

Antiphospholipid antibody (APA) test

This test measures the presence of antibodies that attack phospholipids, which are essential components of cell membranes. APA antibodies are commonly found in people with antiphospholipid syndrome, which can cause recurrent miscarriage and other pregnancy complications.

Anti-thyroid antibody test

This test measures the presence of antibodies that attack the thyroid gland. Anti-thyroid antibodies are commonly found in people with autoimmune thyroid disease, such as Hashimoto’s thyroiditis. Thyroid disorders can cause hormonal imbalances that can affect fertility.

Cytokine analysis

This test measures the levels of cytokines, which are signaling molecules that regulate the immune response. Abnormal cytokine levels may be associated with infertility and pregnancy loss.

Natural killer (NK) cell assay

This test measures the activity of natural killer cells, which are a type of immune cell that plays a role in pregnancy and implantation. High levels of NK cell activity may be associated with infertility and pregnancy loss.

HLA matching

This test determines whether the HLA antigens of the mother and father are compatible. HLA incompatibility can cause the mother’s immune system to attack the fetus, leading to pregnancy complications and infertility.

Immunoglobulin G (IgG) and immunoglobulin M (IgM) testing

This test measures the levels of IgG and IgM antibodies, which are involved in the immune response. Abnormal levels of these antibodies may be associated with infertility and pregnancy loss.

Genetic testing

This may be recommended to identify any genetic mutations that could be contributing to infertility or autoimmune disorders.

The low-down on lymphocytes

Lymphocytes are the major cell of the immune system. They have a critical role in recognizing and responding to foreign invaders, producing antibodies, and directly attacking infected and cancerous cells.

SEM image of human blood. Red and white blood cells can be seen as well as many smaller platelets. Credit: Bruce Wetzel / Harry Schaefer, National Cancer Institute

Lymphocytes are white blood cells

White blood cells, also known as leukocytes, are a type of blood cell that are part of the body’s immune system. They play an important role in defending the body against infections and diseases. Unlike red blood cells, which primarily carry oxygen throughout the body, white blood cells are involved in recognizing and responding to foreign invaders such as bacteria, viruses, and other pathogens.

White blood cells are produced in the bone marrow and circulate throughout the body in the bloodstream. There are different types of white blood cells, each with their own specific functions. These include:

Neutrophils – the most common type, responsible for attacking bacteria and other pathogens.

Lymphocytes – responsible for producing antibodies that help the body recognize and fight off specific pathogens.

Monocytes – responsible for engulfing and digesting pathogens and debris in the body.

Eosinophils – fight off parasitic infections and are involved in allergic reactions.

Basophils – involved in the body’s allergic reactions and parasitic infections.

The number and types of white blood cells in the body can be measured through a blood test to help diagnose and monitor a wide range of conditions, including infections, autoimmune disorders, and cancer.

SEM image of a human lymphocyte. Credit: Dr. Triche, National Cancer Institute


Lymphocytes are the major cell of the immune system because they are responsible for recognizing and responding to foreign invaders such as viruses, bacteria, and other pathogens. Lymphocytes are produced in the bone marrow and mature in the lymphatic organs such as the thymus, spleen, and lymph nodes.

Lymphocytes are a diverse group of white blood cells that are specialized to perform different roles in the immune system. They are easily distinguishable from other white blood cell types but are difficult to separate into their subgroups with conventional tests. However, with the use of immunophenotyping, which analyses the presence of different cell surface markers / protein molecules, the specific types of immune cells can be identified and quantified.

Immunophenotyping requires a specialized laboratory instrument known as the flow cytometer which detects and identify individual lymphocytes after they have been treated with antibodies selected to identify particular lymphocyte types. Disturbances in the proportions of lymphocyte types may be an indicator that there is an immunological problem, particularly for example, found in patients suffering recurrent pregnancy loss or IVF failure.

Types of lymphocytes

There are 3 main types of lymphocytes, B cells, T cells and NK cells, which all play distinct roles in immune function. Together they form a complex network of immune cells that work together to protect the body from pathogens and other threats.

B cell - Free education iconsB cells
These are responsible for producing antibodies, which are proteins that can recognize and neutralize specific foreign invaders such as viruses and bacteria. When a B cell encounters a foreign invader, it produces antibodies that can bind to the invader and mark it for destruction by other cells in the immune system. B cells are frequently elevated in women with an immune related infertility or recurrent pregnancy losses. 

T cell - Free education icons

T cells
T cells make up the majority of lymphocytes found in the blood. These cells are the most important in our immune system. These are responsible for directly attacking and destroying infected and cancerous cells. They also help to regulate the immune response by releasing chemicals called cytokines that help coordinate the immune response and activate other immune cells. T cell numbers may be low when the immune system is weak (suppressed) and normal when the immune system is healthy. Women with high values may be infertile or suffer recurrent pregnancy losses.

There are several different types of T cells, including:

> Helper T cells (Th cells)
These are the directors of the immune response. They secrete hormone-like substances known as ”cytokines”  that affects the response of other immune cells in the surrounding area thus coordinating the overall immune response.  These “director” cells became known as “T helper cells”.  

These lymphocytes were subdivided. Th1 cells are T helper cells that secrete cytokines that direct immune cells to attack target cells (infected or abnormal cells and Th2 cells are T helper cells that secrete different cytokines that oppose the cytokines secreted by Th1 cells. 

Identification of these Th cells requires the Th1 Th2 Assay  Intracellular Cytokine Assay a laboratory test that uses a flow cytometry machine. It is 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. Immune treatment can modulate the Th1/Th2 ratio in these woman to improve their pregnancy outcome.

> Cytotoxic T cells (Tc cells)
These T cells directly attack and destroy infected or cancerous cells. They recognize infected cells by detecting the presence of foreign antigens on their surface and then release toxic molecules that can kill the infected cells. They are infrequently abnormal in women with reproductive issues.

> Regulatory T cells (Treg cells)
These are a small but critical subset of T cells which have a role of maintaining immune homeostasis by, for example, regulating immune tolerance. They help suppress the immune response to prevent autoimmune reactions. Irregularities in Treg function and number can result in loss of tolerance and autoimmune disease. They play a critical role in maintaining immune tolerance and preventing the immune system from attacking the body’s own tissues.

These cells are an important marker in reproductive immunology. It has been found that pregnancy exhibiting low numbers of Treg cells around the time of implantation are more likely to result in miscarriage. It has been seen that rapid immunotherapy treatments can save these pregnancies. In general, it has been found that, low levels of Treg cells is associated with recurrent implantation failure, recurrent miscarriage, fetal growth retardation, preeclampsia, premature rupture of the membranes (PROM), and preterm labor,

They can be identified using flow cytometry in the Treg Cell Assay test which is an important test particularly for women who do not have abnormalities in other immunological tests.

SEM image of Treg cells (red) interacting with antigen-presenting cells (blue). Credit: NIAID by CC 2.0
Nk cell - Free education iconsNatural killer (NK) cells
These are another type of lymphocyte (not considered either B or T cell types) that can directly attack and destroy infected and cancerous cells. NK cells are part of the innate immune system and do not require prior exposure to an antigen in order to become activated, hence their name “natural killers”. They detect and kill by recognizing certain markers on the surface of infected or abnormal cells and releasing toxic molecules that cause the target cell to undergo apoptosis (programmed cell death).
When their number reaches a certain level they are likely to be associated with reproductive failure. To confirm suspicion that natural killer cells may be functioning too aggressively a Natural Killer (NK) Cell Assay is performed. This test uses a precise technique that determines the number and activity and thus killing capacity of these cells. The woman’s nk cells are separated from a blood sample and cultured at different dilutions with target cells and the killing activity is measured using a flow cytometer.
SEM image of a human NK cell. Credit: NIAID

Immunological investigations

Recurrent miscarriage

Recurrent miscarriage is defined as the loss of two or more consecutive pregnancies before the 20th week of gestation. Investigating recurrent miscarriages involves a comprehensive evaluation of both the mother and the fetus to identify any underlying causes that may be contributing to the miscarriages.

Find out about the scientific approaches that may be used to investigate recurrent miscarriages.

Scientific investigations

Unexplained infertility

Unexplained infertility is a diagnosis given to couples who have been trying to conceive for at least one year but have no identifiable cause for their infertility. Investigating unexplained infertility can be a complex process and may involve several scientific approaches. Read about some of the common approaches that may be used to investigate unexplained infertility.


The Clinical Immunology Laboratory

Rosalind Franklin University

The Clinical Immunology Laboratory at Rosalind Franklin University of Medicine and Science is a state-of-the-art diagnostic laboratory that provides a wide range of immunological testing services. The laboratory is accredited by the College of American Pathologists and is staffed by experienced and highly trained laboratory professionals.

The laboratory was established in 1988 to provide services and specialized tests in clinical immunology. It has performed scientific research in the field of human reproduction for over three decades and it continues to develop new diagnostic and therapeutic approaches for immunological diseases.

The laboratory offers specialist tests to evaluate the immune system including assays for autoantibodies, flow cytometric based tests for phenotypes of white blood cells, cytotoxicity assays for NK function and assays for intracellular cytokines. In addition, molecular based assays for mutations of genes involved in coagulation abnormalities, HLA allele assays and tests for STDs are performed.

Diagnostic Tests

Immune Function Assays by Flow Cytometry
NK Cell Cytotoxicity Assay
Functional NK Assay with Prednisolone
TH1/TH2 Intracellular Cytokine Ratio
TH1/TH2 Cytokine Ratios by Flow Cytometry with IVIG
TH1/TH2 Cytokine Ratios by Flow Cytometry with Prednisolone
Reproductive Immunophenotype
Immunodeficiency Panel
Leukocyte Antibody Detection
Platelet Auto-antibodies

Autoimmune Assays
Anti-phospholipid Antibodies Panel
Anti-β2 Glycoprotein I Antibodies
Anti-Nuclear Antibodies
Anti-DNA Antibodies Panel
Anti-Extractable Nuclear Antibodies Panel
Anti-thyroid Antibodies Panel

HLA-DQα Alleles
HLA-DQβ Alleles
HLA-A,-B,-C Alleles
HLA-DR Alleles
HLA-C Group Type
KIR Genotyping

Inherited Thrombophilia Panel
(Gene Polymorphisms)
Factor V Leiden Mutation
Factor VH1299R (HR2) Mutation
MTHFR C677T Mutation
MTHFR A1298C Mutation
PAI-1 4G/5G Mutation
Prothrombin G 20210A Mutation
HPA 1a/1b Mutation
β-Fibrinogen G455A Mutation
Factor XIII V34L Mutation

Endometrial Biopsy Sample Assays

Endometrial Immune Profile
Human herpesvirus-6 (HHV-6) qRT-PCR test
Decidualization Score, RNA Sequencing

Dimitri Papanikolaou

Director Life Clinic Athens,
Specialist reproductive immunologist


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