Pure Red Cell Aplasia with Del(20q) Sensitive for Immunosuppressive Treatment.

Pure red cell aplasia (PRCA) is a rare syndrome that only affects the erythroid lineage. It is defined by a normocytic, normochromic anemia with a marked reticulocytopenia and severe reduction or absence of erythroid precursors in the bone marrow. Treatment of primary, idiopathic PRCA is immunosuppressive therapy. Although it is rare, isolated cytogenetic abnormalities can be seen in PRCA, and abnormal karyotype is associated with poor response to immunosuppressive therapy and poor prognosis. We describe a 77-year-old male with primary, idiopathic PRCA and a deletion of chromosome 20q, del(20q), in the bone marrow cells. He was successfully treated with immunosuppressive therapy and became transfusion-independent. The same cytogenetic abnormality has also been described in a few other reports; taken together, these observations suggest that del(20q) may represent a recurrent cytogenetic abnormality in PRCA. Our case report clearly illustrates that even patients with primary PRCA and an abnormal karyotype can respond to immunosuppression and become transfusion-independent.

Splenic tyrosine kinase (SYK) inhibitors and their possible use in acute myeloid leukemia.

INTRODUCTION: Splenic tyrosine kinase (SYK) is a non-receptor tyrosine kinase. It is important for downstream signaling from several cell surface receptors, including Fc receptors, complement receptors and integrins. SYK can have either oncogenic or tumor suppressor activity in human malignancies. Recent studies suggest that SYK inhibition may have an antileukemic effect in human acute myeloid leukemia (AML). AREAS COVERED: Relevant publications were identified through literature searches in the PubMed database. We searched for (i) original articles describing the results from clinical studies of SYK inhibition; (ii) published articles describing the importance of SYK in human malignancies, especially AML. EXPERT OPINION: SYK is important for the downstream signaling from several cell surface receptors. There is also a crosstalk between SYK and signaling initiated through ligation of Toll like receptors, and SYK is thereby linked with the NFκB mediated transcriptional regulation. SYK activation will also influence PI3K-Akt-mTOR signaling. Several of these signaling events are important for survival and proliferation of primary human AML cells. In the present review we describe and discuss the role of SYK in human AML, and these data suggest that SYK inhibition is a possible therapeutic strategy in human AML.