In allogeneic peripheral blood stem cell transplantation, it is essential to accurately predict stem cell yield before collection in order to minimize burden on the donor and to ensure optimal cell dose for recipients. Therefore, we retrospectively examined allogeneic peripheral blood stem cell collection in 92 healthy donors, and analyzed factors that affect stem cell collection yield. Donors included 32 women (34.8%), and median age and platelet count before G-CSF administration were 41.5 years (14-61) and 24.7 × 10⁴/μl (13.9-41.0). Median ratio of actual G-CSF dose to the standard dose according to the package insert was 96.3% (56.4-109.0). Median blood throughput and CD34⁺ cell yield on day 1 of collection (day 4 of G-CSF initiation) were 10 l (4.5-18) and 1.96 × 10⁸ cells (0.43-6.23), and 14 patients (15.2%) required collection for at least 2 days. Older age, lower platelet count before starting G-CSF administration, and lower G-CSF dose in donors were associated with a significantly reduced yield of CD34⁺ cells. Our results suggest the importance of administering an adequate dose of G-CSF, and that reliable yield prediction based on pre-collection factors may help reduce the donor burden by preventing extension of the collection schedule.

The patient was a 63-year-old man with non-small cell lung cancer. He was treated with nivolumab as second-line therapy. On the 68th day, nivolumab was discontinued due to pneumonitis. On the 111th day, rash, liver dysfunction and pneumonitis were observed and administration of systemic steroid was started. On the 115th day, the sudden progression of anemia required blood transfusion. The irregular antibody test and direct antiglobulin test were positive. The antibody dissociation test showed non-specificity of autoantibodies. On ZZAP treatment, his blood type was B, Rh blood type was CcDee, and no alloantibodies were identified. He was diagnosed with autoimmune hemolytic anemia (AIHA) and was transfused with a total of 12 units of weakly aggregation-reactive and E-antigen-negative red blood cells. The hemolytic anemia gradually improved with steroid pulse therapy. AIHA as an immune-related adverse event is typically severe and requires blood transfusion, which in turn requires the prompt determination of blood type and securing of red blood cell products with low reactivity.

Although the use of IgA-free blood products for IgA-deficient patients is recommended, transfusion countermeasures for non-IgA-deficient patients with anti-IgA antibodies have not been established. Here, we report a patient with anti-IgA antibodies who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen (HLA) -matched unrelated donor using washed platelet products and removal of donor plasma from the bone marrow. The case patient was a 48-year-old man who had primary myelofibrosis and no history of allergy, blood transfusion, or surgery. Anaphylaxis appeared during platelet transfusion 9 days after his first transfusion. Although there was no IgA deficiency, IgG-type anti-IgA antibodies were detected in the pre-transfusion sample. However, the antibody acquisition mechanism was unclear. No adverse reactions to blood transfusion were seen with the use of washed platelet products. Although it was an ABO-matched unrelated allogeneic transplant, no anaphylactic reactions or side effects were seen with stem cell infusion by removal of donor plasma from bone marrow. After transplantation, donor-type hematopoiesis occurred, and the anti-IgA antibody titer decreased with time. Even with non-IgA-deficient patients with anti-IgA antibodies, removal of donor plasma from bone marrow and preparation of washed blood products is important in ensuring safe transplantation.