Efficacy of ruxolitinib in the treatment of relapsed/refractory large granular lymphocytic leukaemia

Large granular lymphocytic (LGL) leukaemia is a rare chronic lymphoproliferative disorder characterized by an expansion of cytotoxic T or NK cells. Despite a usually indolent evolution, most patients will require a treatment over the course of the disease because of cytopenia or symptomatic associated autoimmune disorders. First-line treatment is based on immunosuppressive agents, namely cyclophosphamide, methotrexate and ciclosporin. However, relapses are frequent, and there is no consensus on the management of relapsed/refractory patients. The implication of the JAK/STAT pathway in the pathogenesis of this disease has prompted our group to propose treatment with ruxolitinib. A series of 21 patients who received this regimen is reported here. Ten patients (47.6%) were refractory to the three main immunosuppressive drugs at the time of ruxolitinib initiation. Ruxolitinib yielded an overall response rate of 86% (n = 18/21), including 3 complete responses and 15 partial responses. With a median follow-up of 9 months, the median response duration was 4 months. One-year event-free survival and 1-year overall survival were 57% and 83% respectively. Mild side effects were observed. Biological parameters, notably neutropenia and anaemia, improved significantly, and complete molecular responses were evidenced. This study supports ruxolitinib as a valid option for the treatment of relapsed/refractory LGL leukaemia.

Raman scattering as a characterization tool for epitaxial GaN thin films grown on sapphire by turbo disk metal-organic chemical vapor deposition

Thin layers of GaN, a few micrometers thick, grown on sapphire substrate, are the basic structure in the rapidly developing GaN-based blue optoelectronics devices. We are looking for nondestructive, effective, and convenient characterization tools for GaN/sapphire. Ordinary Raman scattering measurements have limited use because strong Raman signals from the sapphire substrate overwhelm the GaN Raman features. We describe two techniques for making commercial laser Raman systems serve as convenient characterization tools for GaN/sapphire. One uses a near right-angle laser beam incidence, and the other uses microscope lens focusing. In these two ways the detected GaN Raman signals are much stronger than sapphire features, and correct assignments can be made quickly.