To maintain a viable bone marrow (BM) registry for unrelated haematopoietic stem cell (HSC) transplantations, new donor candidates must be continually recruited. The Japanese Red Cross Society is collaborating with the Japan Marrow Donor Program (JMDP) to recruit donors.
In the past decade, 97.7% of BM donor registrations have occurred at blood donation sites. In a 2016 survey of new BM registrants, 80.8% indicated that they had donated blood within the previous two years. The BM donor application form then was changed to give donors the option of providing their blood donor ID number. In the one-year period from May 2017, 84.9% of new BM donor registrants provided their blood donor ID number.
These findings suggest that there is a marked overlap between people who wish to donate HSC and those who wish to donate blood. This indicates that our collaboration with the JMDP at blood donation sites is an efficient strategy and can be considered to the recruitment of reliable HSC donors. As the Japanese Red Cross Society manages both the BM donor registration system and the blood service registration system, the exchange or even merger of donor information from these systems would improve donor safety and work efficiency.
Heparin-induced thrombocytopenia (HIT) is caused by the production of autoantibodies against heparin and platelet factor 4 (PF4) complexes, which have platelet-activating properties. Therefore, HIT patients are at high risk of systemic thromboembolism.
Here, we present a patient (87-year-old female) with myeloproliferative neoplasm (MPN) complicated with HIT. Five days after discontinuing a six-day-long prophylactic heparin regimen following hemicolectomy due to colon cancer, the patient exhibited deep vein thrombosis. A therapeutic dose of heparin caused a sudden drop in platelet count and exacerbated systemic venous/arterial thromboembolism on the fourth day of heparin therapy, suggesting complication of HIT. Immediate discontinuation of heparin improved the symptoms and thrombocytopenia. The HIT diagnosis was later confirmed using serological assays as follows: anti-PF4/heparin IgG antibodies were detected using ELISA, and their platelet-activating properties at therapeutic concentrations of heparin were proved by platelet activation assay using washed platelets.
MPN is not always considered a risk factor for HIT. However, HIT in patients with MPN can be a deteriorating factor for unexpected thromboembolism. Hence, HIT should be included in differential diagnosis lists for MPN patients who develop thrombocytopenia and multiple thrombosis after heparin administration, rather than relying on platelet transfusions without further diagnostic procedures.
A 66-year-old male was diagnosed with polycythemia vera (PV) in September 200X. Although exsanguination was regularly performed, acute myelogenous leukemia was detected in November 200X+3. Following complete remission, non-myeloablative bone marrow transplantation from an HLA-matched sibling donor was conducted in February 200X+4. The ABO blood group was determined to be a major-minor mismatch. Engraftment was achieved on Day 20. Although acute GVHD was confirmed to be a maximum of grade 2, systemic treatment was not required. The stage of chronic GVHD was also confirmed to be limited. Blood-type transition to the donor's blood type was confirmed on Day 577. Immunosuppressive therapy was discontinued on Day 628. On Day 1,697, blood group typing was incidentally performed and demonstrated heterogeneous blood groups. Bone marrow puncture was performed on the same day. While there was no recurrent tumor, the sample was a mixed chimera consisting of 79.6% of cells from the recipient and 19.6% of cells from the donor. Rejection was noted on Day 1,931. However, there has been no relapse, and the patient has remained negative for the JAK2 gene mutation. While it is difficult to detect relapse-free rejection in patients with long-term remission after transplantation, follow-up involving blood-group investigation may be necessary.