Evaluation of Micro RNA-155 Expression in Relation to Alloantibody Formation in Transfusion-Dependent Patients

Transfusion-dependent patients, particularly those with β-thalassemia major, require lifelong regular red blood cell (RBC) transfusions to maintain adequate hemoglobin levels and prevent severe anemia. Although transfusion therapy significantly improves survival and quality of life, it is associated with several immunological complications, the most important of which is red cell alloimmunization. Alloimmunization occurs when the recipients immune system recognizes foreign antigens on donor RBCs and produces alloantibodies against them, which may lead to hemolytic transfusion reactions, difficulty in finding compatible blood and increased transfusion requirements (1). The incidence of RBC alloimmunization in transfusion-dependent patients varies widely but remains a major clinical challenge in transfusion medicine (2).

Recent advances in molecular hematology have highlighted the importance of microRNAs (miRNAs) in regulating immune responses and hematopoiesis. MicroRNAs are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level and play a key role in both innate and adaptive immunity (3). Among them, microRNA-155 (miR-155) has emerged as a critical regulator of inflammatory pathways, antigen presentation, and lymphocyte activation. It modulates immune cell differentiation and cytokine production, thereby influencing immune responses to foreign antigens (4, 5).

In patients with β-thalassemia, miR-155 is also implicated in erythropoiesis and ineffective red cell production, suggesting its involvement in both hematologic and immunologic pathways of the disease. Increased expression of miR-155 has been reported in thalassemic erythroid cells and is associated with altered erythroblast proliferation and differentiation (6).

Importantly, recent studies suggest that miR-155 may contribute to the development of alloimmunization in transfusion-dependent patients.

Study Overview

• Status: Not yet recruiting
• Conditions: Beta Thalassemia; Red Cell Alloantibodies; Blood Transfusion-Dependent

Detailed Description

Transfusion-dependent patients, particularly those with β-thalassemia major, require lifelong regular red blood cell (RBC) transfusions to maintain adequate hemoglobin levels and prevent severe anemia. Although transfusion therapy significantly improves survival and quality of life, it is associated with several immunological complications, the most important of which is red cell alloimmunization. Alloimmunization occurs when the recipients immune system recognizes foreign antigens on donor RBCs and produces alloantibodies against them, which may lead to hemolytic transfusion reactions, difficulty in finding compatible blood and increased transfusion requirements (1). The incidence of RBC alloimmunization in transfusion-dependent patients varies widely but remains a major clinical challenge in transfusion medicine (2).

Recent advances in molecular hematology have highlighted the importance of microRNAs (miRNAs) in regulating immune responses and hematopoiesis. MicroRNAs are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level and play a key role in both innate and adaptive immunity (3). Among them, microRNA-155 (miR-155) has emerged as a critical regulator of inflammatory pathways, antigen presentation, and lymphocyte activation. It modulates immune cell differentiation and cytokine production, thereby influencing immune responses to foreign antigens (4, 5).

In patients with β-thalassemia, miR-155 is also implicated in erythropoiesis and ineffective red cell production, suggesting its involvement in both hematologic and immunologic pathways of the disease. Increased expression of miR-155 has been reported in thalassemic erythroid cells and is associated with altered erythroblast proliferation and differentiation (6).

Importantly, recent studies suggest that miR-155 may contribute to the development of alloimmunization in transfusion-dependent patients.

Therefore, investigating the association between miR-155 expression and RBC alloimmunization may provide valuable insights into the molecular mechanisms underlying immune dysregulation in transfusion-dependent patients and may help identify novel biomarkers for predicting alloimmunization risk.

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Asmaa Mohamed Elsayed, Assistant lecturer; Phone Number: 01027575354; Email: Momenasmaa392@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Include patients with chronic blood transfusion and not recive anti immune drugs Not with malignancy diseases

Description

Inclusion Criteria:

1- Confirmed transfusion-dependent . 2-Regular RBC transfusion history 3- Age ≥5 years

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Exclusion Criteria:

• 1- Autoimmune diseases 2- Active infections or inflammatory conditions. 3- Immunosuppressive therapy Ý

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Relative expression level of microRNA-155	Assessment of the relative expression level of microRNA-155 in transfusion-dependent patients with red cell alloimmunization compared with non-alloimmunized transfusion-dependent patients using quantitative real-time PCR.	At the time of patient enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of red cell alloantibodies	Detection and identification of red blood cell alloantibodies in transfusion-dependent patients using standard immunohematological techniques.	At enrollment

Collaborators and Investigators

• Sponsor: Assiut University

Publications and helpful links

General Publications

• 1 - Amini MA et al. Association of MicroRNA-155 with Alloimmunization in Transfusion-Dependent Thalassemia Patients. Hemoglobin. 2025. 2- Vamvakas EC, pineda AA. Red cell alloimmunization in transfusion-dependent patients. Transfusion medicine reviews. 2010. 3- Bala S et al. Increased microRNA-155 expression in serum and monocytes during inflammatory responses. J Transl Med. 2012. 4- OConnell RM et al. MicroRNA-155 regulates immune responses and inflammation. J Immunology. 2018. 5- Thai TH et al. miR-155 regulates dendritic cell function and T-cell responses. Cell & Bioscience. 2011. 6- Georgantas RW et al. MicroRNA-155 targets genes involved in hematopoietic differentiation. Proceedings of the National Academy of Science. 2007.

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: March 14, 2026
• First Submitted That Met QC Criteria: March 14, 2026
• First Posted (Actual): March 18, 2026

Study Record Updates

• Last Update Posted (Actual): April 6, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Genetic Diseases, Inborn; Hematologic Diseases; Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia; Hemoglobinopathies; Thalassemia; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Hemic and Lymphatic Diseases; beta-Thalassemia
• Other Study ID Numbers: MIR155-ALLO-TDT-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No