Harris platelet syndrome, previously known as asymptomatic constitutional macrothrombocytopenia, is the most common inherited giant platelet disorder in the Indian subcontinent. It is characterized by a functional thrombocytopenia due to the presence of giant platelet cells.
| Harris platelet syndrome | |
|---|---|
| Specialty | Hematology |
Presentation edit
Harris platelet syndrome was identified among healthy blood donors in the north-eastern part of the Indian subcontinent, characterized by absent bleeding symptoms, mild to severe thrombocytopenia (platelets rarely < 50 × 109/L) with giant platelets (Mean platelet volume 10fL) and normal platelet aggregation studies with absent MYH9 mutation.[1][2]
In the blood donors with Harris platelet syndrome, authors found a statistically higher mean platelet volume, red cell distribution width, lower platelet count and platelet biomass.[3]
Harris platelet syndrome has been discovered in individuals without a north-east Indian ethnic background, broadening the scope of possible ethnicities that are effected and emphasizing the importance of adequate laboratory studies.[4]
Diagnosis edit
The diagnosis of Harris platelet syndrome is made by ascertaining the ethnicity of the patient, as well as assessing for conditions causing acquired thrombocytopenias, and after also excluding the known inherited giant platelet disorders and other causes of thrombocytopenia. The diagnostic approach typically consists of blood tests and blood smears to check for platelet count, size, and morphology; more advanced tests can be used to determine platelet function. Genetic testing is also commonly done.
Treatment edit
Patients with Harris platelet syndrome do not suffer from bleeding disorders despite a low platelet count. The unique structure of the megakaryocytes allow them to be functional in clotting, therefore making Harris platelet syndrome relatively benign. Additionally, it has been found that patients with Harris platelet syndrome have a low risk of bleeding during surgery.[5] Some patients with inherited giant platelet disorders are treated inappropriately with corticosteroids, immunoglobulin infusions and even splenectomy.[6]
Mechanism edit
Actin-binding proteins have been linked to maintaining the structure of the large platelets. However, enzymatic activity allows for functional clotting activity regardless of the size of the thrombocytes.[7] Genomic studies have found mutations in various pathways that could be the cause of Harris platelet syndrome, but further studies are required.
Prevalence edit
Harris platelet syndrome has been found in up to one-third of all blood donors In the West Bengal region of India.[3] It is also frequently found in the north-east region of South Asia, including Nepal, Bhutan, and Bangladesh in addition to India.
Terminology edit
In 2002, this syndrome was called "asymptomatic constitutional macro thrombocytopenia".[1]
In 2005, to avoid confusion between asymptomatic constitutional macro thrombocytopenia and congenital amegakaryocytic thrombocytopenia, the latter was called Harris platelet syndrome.[2]
References edit
- ^ a b Naina HV, Nair SC, Daniel D, George B, Chandy M (June 2002). "Asymptomatic constitutional macrothrombocytopenia among West Bengal blood donors". Am. J. Med. 112 (9): 742–3. doi:10.1016/S0002-9343(02)01114-2. PMID 12079722.
- ^ a b Naina HV, Nair SC, Harris S, Woodfield G, Rees MI (November 2005). "Harris syndrome - a geographic perspective". J. Thromb. Haemost. 3 (11): 2581–2. doi:10.1111/j.1538-7836.2005.01601.x. PMID 16241959. S2CID 19289239.
- ^ a b Naina HV, Harris S (2010). "Platelet and red blood cell indices in Harris platelet syndrome". Platelets. 21 (4): 303–6. doi:10.3109/09537101003615402. PMID 20201635. S2CID 27731719.
- ^ Aslan, Deniz (November 2016). "Harris Platelet Syndrome in Patients of Non-Indian Origin". Journal of Pediatric Hematology/Oncology. 38 (8): e326–e328. doi:10.1097/MPH.0000000000000602. ISSN 1536-3678. PMID 27299593. S2CID 23158036.
- ^ Neethirajan, Soma Ganesh Raja; Ramesh, Aishwarya; Parameswari, Aruna (February 2021). "Regional Anaesthesia in Harris Platelet Syndrome for Transurethral Resection of Prostate-A Clinical Conundrum or Certitude?". Turkish Journal of Anaesthesiology and Reanimation. 49 (1): 67–69. doi:10.5152/TJAR.2020.90008. ISSN 2667-677X. PMC 7932712. PMID 33718909.
- ^ Gohda F, Uchiumi H, Handa H, et al. (2007). "Identification of inherited macrothrombocytopenias based on mean platelet volume among patients diagnosed with idiopathic thrombocytopenia". Thrombosis Research. 119 (6): 741–746. doi:10.1016/j.thromres.2006.06.011. PMID 16916536.
- ^ Karmakar, Shilpita; Saha, Sutapa; Banerjee, Debasis; Chakrabarti, Abhijit (January 2015). "Differential proteomics study of platelets in asymptomatic constitutional macrothrombocytopenia: altered levels of cytoskeletal proteins". European Journal of Haematology. 94 (1): 43–50. doi:10.1111/ejh.12398. ISSN 0902-4441. PMID 24934967. S2CID 35510495.