Plasma exchanges for severe acute neurological deterioration in patients with IgM anti-myelin-associated glycoprotein (anti-MAG) neuropathy.

Monoclonal IgM anti-myelin-associated glycoprotein (MAG) antibody-related peripheral neuropathy (anti-MAG neuropathy) is predominantly a demyelinating sensory neuropathy with ataxia and distal paresthesia. The clinical course of anti-MAG neuropathy is usually slowly progressive making difficult the identification of clear criteria to start a specific treatment. Although no consensus treatment is yet available, a rituximab-based regimen targeting the B-cell clone producing the monoclonal IgM may be proposed, alone or in combination with alkylating agents or purine analogs. However, in some rare cases, an acute and severe neurological deterioration can occur in few days leading to a rapid loss of autonomy. In these cases, a treatment rapidly removing the monoclonal IgM from the circulation might be useful before initiating a specific therapy. We report successful treatment with plasma exchanges (PE) in four patients presenting with acute neurological deterioration. PE allowed a dramatic and rapid neurological improvement in all patients. PE are safe and may be useful at the initial management of these cases of anti-MAG neuropathy.

Pre-transplant donor CD4- invariant NKT cell expansion capacity predicts the occurrence of acute graft-versus-host disease.

Clinically useful pre-transplant predictive factors of acute graft-versus-host-disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-SCT) are lacking. We prospectively analyzed HSC graft content in CD34+, NK, conventional T, regulatory T and invariant natural killer T (iNKT) cells in 117 adult patients before allo-SCT. Results were correlated with occurrence of aGVHD and relapse. In univariate analysis, iNKT cells were the only graft cell populations associated with occurrence of aGVHD. In multivariate analysis, CD4- iNKT/T cell frequency could predict grade II-IV aGVHD in bone marrow and peripheral blood stem cell (PBSC) grafts, while CD4- iNKT expansion capacity was predictive in PBSC grafts. Receiver operating characteristic analyses determined the CD4- iNKT expansion factor as the best predictive factor of aGVHD. Incidence of grade II-IV aGVHD was reduced in patients receiving a graft with an expansion factor above versus below 6.83 (9.7 vs 80%, P<0.0001), while relapse incidence at two years was similar (P=0.5).The test reached 94% sensitivity and 100% specificity in the subgroup of patients transplanted with human leukocyte antigen 10/10 PBSCs without active disease. Analysis of this CD4- iNKT expansion capacity test may represent the first diagnostic tool allowing selection of the best donor to avoid severe aGVHD with preserved graft-versus-leukemia effect after peripheral blood allo-SCT.

[Vascular myeloproliferative neoplasm with normal cell blood count: Exploration and medical management]. / Les syndromes myéloprolifératifs d'expression vasculaire à numération normale : comment les explorer ?

UNLABELLED: Negative BCR ABL myeloproliferative neoplasm (MPN) such as polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (MFP) are clonal hematological malignancies and may lead to a high risk of venous, arterial or microcirculatory thrombosis. Atypical sites of thrombosis can sometimes reveal the neoplasm disorder. Their diagnoses are a major issue because of the propensity to develop acute myeloid leukemia and/or myelofibrosis. The acquired JAK2V617F variant (Janus kinase 2; 9p24) is a prevalent MPN and also a sensitive marker for PV diagnosis (95% positive mutation), but not specific since found in approximately 50% of patients with ET and MFP. PATIENT AND METHODS: We present a diagnostic and a therapeutic approach based on one patient with microcirculatory ischemic manifestations in the toes, and who had strictly normal cell blood counts and was positive for JAK2V617F mutation: thrombotic risk factor evaluation; bone marrow biopsy; red cell adhesion assays. These experimental assays are promising for the development of new therapeutics in MPN; they assess red cell adherence to the vascular endothelium after the phosphorylation of Lu/BCAM subsequent to a positive JAK2V617F mutation. RESULTS: Compared with controls, our patient exhibited increased Lu/BCAM receptor phosphorylation and red blood cell adhesion. CONCLUSION: This development may lead to improved care for patients with thrombotic manifestations, normal blood cell counts, and a positive JAK2V617F mutation: multidisciplinary management, including regular hematological monitoring, could lead to the introduction of a cytoreductive treatment.