Circulating Cd34+ cell count differentiates primary myelofibrosis from other Philadelphia-negative myeloproliferative neoplasms: a pragmatic study.

A high number of circulating CD34+ cells has been advocated to distinguish primary myelofibrosis from other Philadelphia-negative myeloproliferative neoplasms. We re-evaluated the diagnostic interest of measuring circulating CD34+ cells in 26 healthy volunteers and 256 consecutive patients at diagnosis for whom a myeloproliferative neoplasm was suspected. The ROC curve analysis showed that a number of CD34+ <10/µl excludes the diagnosis of primary myelofibrosis with a sensitivity of 97 % and a specificity of 90 % (area under the curve: 0.93 [0.89-0.98]; p < 0.001). Patients with PMF harboring a CALR mutation had more circulating CD34+ cells than patients with either a JAK 2 or MPL mutation (p = 0.02 and p < 0.01, respectively). These results suggest that this fast, simple, non-invasive, and standardized test is of particular interest to exclude the diagnosis of primary myelofibrosis.

[A subacute dementia: Inflammatory cerebral amyloid angiopathy]. / Une démence rapidement progressive: l'angiopathie amyloïde cérébrale subaiguë inflammatoire.

We report a case of inflammatory cerebral amyloid angiopathy (CAA) that led to rapid cognitive decline, seizures, visual hallucinations, hyperproteinorrachia and right hemispheric leukopathy. Brain biopsy gave the diagnosis of CAA. Although no inflammatory infiltrate was found in the biopsy sample, corticosteroids led to a regression of the radiological lesions without significant clinical improvement. CAA is a rare disease, defined by lesions of classical cerebral amyloid angiopathy and perivascular infiltrates in contact with the affected vessels. In cases of rapidly progressive dementia associated with leukopathy, inflammatory amyloid angiopathy should be considered as cognitive disorders may improve after immunosuppressive therapy.