What is Lymphocyte Immunization Therapy (LIT)?

During pregnancy, the maternal immune system must adapt to support an embryo that carries genetic material from both partners. In some cases, this immune adaptation may not function optimally, and that may be explored as one of several possible contributing factors in recurrent pregnancy loss or repeated implantation failure.

LIT is a minimally invasive therapy in which prepared lymphocytes are administered through superficial skin injections under specialist supervision. The aim is to support immune tolerance and reproductive balance in appropriately selected patients.

How LIT Works

LIT is designed to support a more balanced reproductive immune response in selected cases.

Supports immune tolerance

Helps create conditions where the maternal immune system is better able to coexist with the developing embryo.

Encourages a more receptive environment

May assist in shifting the reproductive environment toward one that is more supportive of implantation and early pregnancy.

Fits into a personalised fertility plan

LIT is usually considered only after proper assessment, testing, and case review by a specialist team.

Who May Be a Good Candidate for LIT?

LIT is a highly specialised treatment and is not recommended for every fertility patient. At ALIV, it may be considered only after appropriate clinical evaluation.

Lymphocyte Immunization Therapy (LIT) at ALIV

Overcoming Recurrent Pregnancy Loss & IVF Failure

Lymphocyte Immunization Therapy (LIT) is an advanced reproductive immunology treatment designed to help women who have experienced unexplained recurrent pregnancy loss (RPL) or recurrent implantation failure (RIF) during IVF. 

At ALIV, we utilize cutting-edge immunology to address the unseen barriers to pregnancy. By correcting maternal-fetal immune incompatibility, LIT helps your body protect and nurture your embryo, maximizing your chances of a successful, healthy pregnancy.

What is Lymphocyte Immunization Therapy (LIT)?

During a healthy pregnancy, the maternal immune system must develop an "active tolerance" to the embryo, which functions as a semi-allograft since it contains the father's genetic material. In some women, this natural adaptation fails, and the immune system mistakenly mounts a rejection response against the embryo. 

LIT is a minimally invasive therapy that safely introduces concentrated white blood cells (lymphocytes) from the male partner—or a carefully screened donor—into the female partner's skin via shallow intradermal injections. This creates a "friendly introduction" to the paternal antigens, training the mother’s immune system to recognize the embryo as safe rather than a threat.

How Does LIT Therapy Work?

LIT fundamentally rebalances the maternal immune environment at the cellular level:

• Production of Blocking Antibodies: The therapy stimulates the maternal immune system to produce vital "blocking antibodies," such as Anti-Paternal Cytotoxic Antibodies (APCA) and MLR-Bf. These antibodies act as a protective shield, masking the paternal antigens on the embryo so maternal immune cells cannot attack them.

• Regulating Immune Cells: LIT effectively downregulates the cytotoxicity of hyperactive Natural Killer (NK) cells, which are often overexpressed in women with recurrent miscarriages.

• Shifting to a Nurturing Environment: The treatment promotes the expansion of protective Regulatory T cells (Tregs) and shifts the uterus from a hostile, pro-inflammatory (Th1/Th17) state to a pregnancy-friendly, anti-inflammatory (Th2) environment.

*Note: At ALIV, we strictly utilize fresh, non-refrigerated lymphocytes. Research shows that storing cells at cold temperatures degrades CD200—a crucial surface protein that delivers the inhibitory signals required to build maternal tolerance*. 

Who is a Good Candidate for LIT?

LIT is a highly specialized treatment and is not required for every fertility patient. Following a comprehensive immunological assessment, ALIV specialists may recommend LIT for couples experiencing:

• Idiopathic Recurrent Pregnancy Loss (RPL): Two or more consecutive early miscarriages where genetic, anatomical, and endocrine factors are entirely normal.

• Repeated Implantation Failure (RIF): The failure to achieve clinical pregnancy despite the transfer of multiple high-quality or euploid embryos during IVF.

• Negative LAD Test: Patients demonstrating an absence of protective blocking antibodies (a negative Leukocyte Antibody Detection test).

• HLA Sharing or KIR-HLA-C Mismatch: Couples with a high degree of Human Leukocyte Antigen (HLA) sharing, preventing the mother's body from recognizing the embryo as foreign enough to trigger protective tolerance mechanisms.

The LIT Procedure at ALIV

Our protocol is safe, straightforward, and conducted under strict clinical standards:

1. Blood Collection: A small blood sample is drawn from the male partner or donor.

2. Cell Purification: Our advanced laboratory isolates and concentrates the lymphocytes using density gradient centrifugation, ensuring only the necessary immune cells are used.

3. Intradermal Injection: The purified lymphocytes are injected just under the skin of the female partner's forearm. 

4. Monitoring & Boosters: We retest your LAD levels after 4-6 weeks to confirm the production of blocking antibodies. If pregnancy occurs, "booster" sessions may be administered at key milestones (such as fetal heartbeat detection) to maintain immune tolerance through the critical first trimester.

Proven Clinical Success Rates

Recent systematic reviews and meta-analyses provide robust evidence for the efficacy of LIT when applied to properly selected patients:

• Elevated Live Birth Rates: Clinical data shows that successful LIT treatment significantly elevates live birth rates. In women with alloimmune RPL, studies report an overall live birth rate of  65.6%  in the LIT group compared to just  45.2%  in untreated control groups.

• Targeted Efficacy: When fresh lymphocytes are administered at optimal doses, success rates for targeted subgroups can reach  60% to 80% . Furthermore, LIT has been shown to successfully convert up to  77.9%  of patients from a negative to a positive blocking antibody status. 

Is LIT Therapy Safe?

Decades of data indicate that  LIT is a low-risk, well-tolerated procedure  with a safety profile comparable to standard intradermal vaccinations. 

The most common side effects are mild, transient local reactions at the injection site, such as redness, itching, swelling, or small blister formation, which typically resolve within one to two weeks. Systemic reactions like mild flu-like symptoms or low-grade fever occur rarely, and large-scale studies have found no specific risks for anaphylaxis or the induction of autoimmune diseases. 

Partner with ALIV Today

Do not let unseen immunological barriers stand in the way of your family. If you have faced the heartbreak of unexplained miscarriages or IVF failures, ALIV’s specialized Reproductive Immunology team is here to help you uncover the root cause and build a personalized treatment plan.