Impact of screening and exclusion of high anti‐A titer donors on the risk of hemolytic anemia with intravenous immunoglobulin treatment: A hospital‐based cohort study in the US

(3%) and MPL (3%). Interestingly, it has been hypothesized that MDS with ring sideroblasts (MDS-RS) can transform into MDS/MPN-RS-T with acquisition of the JAK-2 mutation. Poor prognostic factors in MDS/MPN-RS-T include older age (>80), low Hb (<8 g/dl), abnormal cytogenetics, the presence of SETBP-1 or ASXL-1 mutations and the absence of SF3B1 or JAK-2 mutations. It is interesting to compare outcomes and variables between MDS/MPN-RS-T and its sister conditions MDS-RS and essential thrombocythemia (ET). A recent study has shown that survival in MDS/MPN-RS-T significantly exceeds that of MDS-RS (76 months versus 63 months) and compares poorly with survival in ET (115 months). Thrombotic events in MDS/MPN-RS-T and ET were shown to exceed those of MDS-RS, which may be expected considering the disease characteristics. Rates of transformation to AML were similar in the two MDS subtypes but lower in ET, the myeloproliferative counterpart. This case is noteworthy as MDS/MPN-RS-T has a relatively low transformation rate to AML, with a leukemic transformation rate per 100 years of 1.8. A recent paper described two cases; both were patients who were aged greater than 70 years and had been diagnosed with MDS/MPN-RS-T at least two years prior to transformation. One patient had cytogenetics exhibiting clonal evolution, with 7q deletion detected in the marrow following transformation, and died from neutropenic sepsis with chemotherapy; the second did not have clonal evolution and was undergoing chemotherapy at the time of publication. Another case report involved a 70-year-old patient who died from AML transformed from MDS/MPN-RS-T; this case involved the development of a monosomy 7 clone in the leukemic marrow. The refractoriness of the transformed AML in our case to multiple lines of chemotherapy also serves to highlight the aggressive nature of the disease. In summary, we describe a case of MDS/MPN-RS-T with transformation to treatment-refractory AML highlighted by the presence of trisomy 13 and resistant thrombocytosis. Although transient, our patient’s relative “response” to oral busulfan was unexpected but does suggest that this therapy may be clinically useful in similar cases.