Protocol for extramedullary hematopoiesis in patients with transfusion‐dependent β‐thalassemia (TDT): A systematic review

Abstract

Background and aims Thalassemia is one of the most common hemoglobinopathies, with around 5% of the world's population expected to have some degree and type of thalassemia. Beta thalassemia (BT) occurs due to a deficient production of the beta‐globin chain of hemoglobin. Extramedullary hematopoiesis (EMH) is one of the complications of BT, mainly observed in minor/intermedia subtypes. EMH is the production of blood cells outside the marrow as a compensatory response to longstanding hypoxia. Due to chronic transfusions, it is not expected in patients with beta‐thalassemia major (BTM). However, there are increasingly reported cases of EMH in BTM. The incidence of EMH in BTM is thought to be <1%. However, it seems that the true incidence is much higher than expected. This review aims to pool the available data and provide cumulative evidence on the reports of EMH in BTM patients. Methods We aim to conduct a systematic review via searching multiple electronic databases (PubMed, Scopus, Google Scholar) to identify eligible articles from any date up to December 2020. Eligible studies should report extramedullary hematopoiesis in BTM. Case reports, case series, observational studies with cross‐sectional or prospective research design, case‐control studies, and experimental studies will be included if found relevant. Two reviewers (FA and ES) will individually analyze the study quality using the statistical methodology and categories guided by the Cochrane Collaboration Handbook, PRISMA guidelines, and Joanna Briggs Institute checklist for case reports and series. Results This study will analyze and incorporate the available evidence on EMH in BTM concerning patient demographics, sites of EMH, management, and clinical outcomes of EMH. Conclusion By summarizing and statistically analyzing the data about EMH in BTM, this study will generate extensive knowledge on the topic for a better understanding of atypical presentations in BTM, a common hemoglobinopathy.

Unveiling Extramedullary Hematopoiesis: A Case Report Highlighting the Causes, Symptoms, and Management Strategies

“…The relative advantages of these treatments have not been firmly established due to the infrequency of the condition. In thalassemic patients, adequate blood transfusions play a crucial role in reducing inefficient hematopoiesis, thereby mitigating the extensive development of extramedullary hematopoiesis [10,11]. It is important to note that complications in hypertransfusion therapy are not uncommon, and efforts should be made to anticipate and prevent them where possible.…”

Recurrent spinal cord compression due to extramedullary hematopoiesis in thalassemia patient

“…The diagnostic procedure of choice is MRI. [18] Imaging of epidural extramedullary hematopoiesis reveals lesions that vary in intensity and contrast enhancement depending on age and the hematopoietic activity of the lesion. [19] Biopsy is not always required for diagnosis, and most authors do not favor a tissue biopsy in such conditions.…”

“…It is typically seen in organs vigorously involved in fetal hematopoiesis, including liver, spleen, and lymph nodes. [ 8 , 9 ] Rarely, it can also be seen in other sites including epidural space, adrenal, pleural, and thyroid. [ 10 , 11 ] EMH in epidural space is a rare and particularly sensitive location as it can cause spinal compression and may present as a paravertebral pseudotumor presenting as back pain and neurological disorder of the lower limbs.…”

“…EMH is defined as a physiological compensatory production of red blood cells in tissues other than bone marrow secondary to chronic anemia. It is typically seen in organs vigorously involved in fetal hematopoiesis, including liver, spleen, and lymph nodes [8,9] . Rarely, it can also be seen in other sites including epidural space, adrenal, pleural, and thyroid [10,11] .…”

Luspatercept, a two‐edged sword in beta‐thalassemia‐associated paravertebral extramedullary hematopoietic masses (EHMs)

“…Surgical decompression (i.e., laminectomy) is mainly restricted to patients presenting with acute neurologic involvement requiring immediate therapy. However, a prompt multimodal therapeutic approach may even be advantageous 7,17 . Allogeneic hematopoietic stem cell transplantation (HSCT) continuous outside trials to be the only widely available curative treatment option in patients with transfusion‐dependent BT.…”