Acute kidney injury secondary to thrombotic microangiopathy associated with idiopathic hypereosinophilic syndrome: a case report and review of the literature.

BACKGROUND: Renal involvement in idiopathic hypereosinophilic syndrome is uncommon. The mechanism of kidney damage can be explained as occurring via two distinct pathways: (1) thromboembolic ischemic changes secondary to endocardial disruption mediated by eosinophilic cytotoxicity to the myocardium and (2) direct eosinophilic cytotoxic effect to the kidney. CASE PRESENTATION: We present a case of a 63-year-old Caucasian man who presented to our hospital with 2 weeks of progressively generalized weakness. He was diagnosed with idiopathic hypereosinophilic syndrome with multiorgan involvement and acute kidney injury with biopsy-proven thrombotic microangiopathy. Full remission was achieved after 8 weeks of corticosteroid therapy. CONCLUSION: Further studies are needed to investigate if age and absence of frank thrombocytopenia can serve as a prognostic feature of idiopathic hypereosinophilic syndrome, as seen in this case.

Characterization of purine-rich element binding protein B as a novel biomarker in acute myelogenous leukemia prognostication.

Acute myelogenous leukemia (AML) is an aggressive hematologic cancer characterized by infiltration of proliferative, clonal, abnormally differentiated cells of myeloid lineage in the bone marrow and blood. Malignant cells in AML often exhibit chromosomal and other genetic or epigenetic abnormalities that are useful in prognostic risk assessment. In this study, the relative expression and novel single-stranded DNA (ssDNA) binding function of purine-rich element binding proteins A and B (Purα and Purß) were systematically evaluated in established leukemia cell lines and in lineage committed myeloid cells isolated from patients diagnosed with a hematologic malignancy. Western blotting revealed that Purα and Purß are markedly elevated in CD33+ /CD66b+ cells from AML patients compared to healthy subjects and to patients with other types of myeloid cell disorders. Results of in silico database analysis of PURA and PURB mRNA expression during hematopoiesis in conjunction with the quantitative immunoassay of the ssDNA-binding activities of Purα and Purß in transformed leukocyte cell lines pointed to Purß as the more distinguishing biomarker of myeloid cell differentiation status. Purß ssDNA-binding activity was significantly increased in myeloid cells from AML patients but not from individuals with other myeloid-related diseases. The highest levels of Purß activity were detected in myeloid cells from primary AML patients and from AML patients displaying other risk factors forecasting a poor prognosis. Collectively, these findings suggest that the enhanced ssDNA-binding activity of Purß in transformed myeloid cells may serve as a unique and measurable phenotypic trait for improving prognostic risk stratification in AML.