Positive predictive value of CD200 positivity in the differential diagnosis of chronic lymphocytic leukemia.

BACKGROUND: The role of CD200 in the differential diagnosis of chronic lymphocytic leukemia (CLL) and classical mantle cell lymphoma (MCL) is well established. Its role in the differential diagnosis of CLL and other lymphoproliferative disorders (LPD) is less clear, in particular its positive predictive value (PPV). MATERIALS AND METHODS: We conducted a systematic review of the use of CD200 in the differential diagnosis of CLL, MCL, and other predominantly leukemic, typically CD103-negative LPD. With the results, we then derived a curve to determine the PPV based on the prevalence of the disorders included in the differential diagnosis. RESULTS: Of 43 publications screened, 27 were included in the systematic review (5,764 patients). The median CD200 positivity rate in all studies and the percentage of CD200-positive (pooled) patients was 100% and 95% (3,061/3,208) in CLL, 4 and 8% (86/1112) in MCL and 56 and 62% (425/689) in other LPD. CONCLUSION: CD200 is suboptimal for the differential diagnosis of CLL and disorders other than nodal MCL.

Flow Cytometry in the Differential Diagnosis of CD10-Positive Nodal Lymphomas.

BACKGROUND: Differences between follicular lymphoma (FL) and diffuse large B-cell lymphoma/high-grade B-cell lymphoma (DLBCL/HGBL) by flow cytometry are underexplored. METHODS: We retrospectively assessed flow cytometry results from 191 consecutive lymph node biopsies diagnosed with FL or DLBCL/HGBL. RESULTS: The only parameters that differed between the 2 groups in the derivation cohort were forward scatter and side scatter (P < 10-6; area under the curve [AUC], 0.75-0.8) and %CD23 (P = .004; area under the receiver characteristic operating curve, 0.64). However, since light scatter characteristics did not distinguish between grade 3 FL and DLBCL/HGBL, we set out to develop a model with high sensitivity for the exclusion of the latter. Several models, including FS and %CD23, were tested, and 2 models showed a sensitivity of >0.90, with negative predictive values of ≥0.95, albeit with low specificity (0.45 to 0.57). CONCLUSION: Two simple models enable the exclusion of DLBCL/HGBL with a high degree of confidence.

Dabigatran for catastrophic antiphospholipid syndrome.

: Vitamin K antagonists (VKA) remain the treatment of choice for catastrophic antiphosphilipid syndrome (CAPS). However, when VKAs do not work for a specific patient, direct oral anticoagulants (DOAC) may be a valid therapeutic alternative. We present a patient with a psychiatric disorder and CAPS who was noncompliant to VKA and low-molecular-weight heparin. He was started on dabigatran and has remained thrombosis-free for 8 years. Due to CAPS he has developed progressive renal failure but dabigatran levels were within the expected range. In conclusion, this case report provides anecdotic evidence that dabigatran may be of use in patients with high-risk APS in whom VKA are not an option.

Indications and use of, and incidence of major bleeding with, antithrombotic agents in myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) and antithrombotic medication both increase the risk of bleeding. We set out to analyze the prevalence of use, indications and bleeding risk of antithrombotic therapy in patients with MDS in a retrospective, single-center study including all patients with MDS with >20 × 109/L platelets. 193 patients (59% male, median age 75 years) were included; 122 did not receive antithrombotic treatment, 51 received antiplatelet agents and 20 received anticoagulants. The cumulative incidence of major bleeding was higher in both the antiplatelet group (11.8% at 4 years, 95% confidence interval [95%CI]: 4.7-22.3%) and the anticoagulation group (21.2% at 4 years, 95%CI 6-42.5%) than in the control group (2.8% at 4 years 95%CI: 0.7-7.3%). The prevalence of use of antithrombotic medication in this cohort of patients with MDS was high and bleeding risk was increased in these patients.