A significant proportion of classic Hodgkin lymphoma recurrences represents clonally unrelated second primary lymphoma.

Despite high cure rates in classic Hodgkin lymphoma (cHL), relapses are observed. Whether relapsed cHL represents second primary lymphoma or an underlying T-cell lymphoma (TCL) mimicking cHL is underinvestigated. To analyze the nature of cHL recurrences, in-depth clonality testing of immunoglobulin (Ig) and T-cell receptor (TCR) rearrangements was performed in paired cHL diagnoses and recurrences among 60 patients, supported by targeted mutation analysis of lymphoma-associated genes. Clonal Ig rearrangements were detected by next-generation sequencing (NGS) in 69 of 120 (58%) diagnoses and recurrence samples. The clonal relationship could be established in 34 cases, identifying clonally related relapsed cHL in 24 of 34 patients (71%). Clonally unrelated cHL was observed in 10 of 34 patients (29%) as determined by IG-NGS clonality assessment and confirmed by the identification of predominantly mutually exclusive gene mutations in the paired cHL samples. In recurrences of >2 years, ∼60% of patients with cHL for whom the clonal relationship could be established showed a second primary cHL. Clonal TCR gene rearrangements were identified in 14 of 125 samples (11%), and TCL-associated gene mutations were detected in 7 of 14 samples. Retrospective pathology review with integration of the molecular findings were consistent with an underlying TCL in 5 patients aged >50 years. This study shows that cHL recurrences, especially after 2 years, sometimes represent a new primary cHL or TCL mimicking cHL, as uncovered by NGS-based Ig/TCR clonality testing and gene mutation analysis. Given the significant therapeutic consequences, molecular testing of a presumed relapse in cHL is crucial for subsequent appropriate treatment strategies adapted to the specific lymphoma presentation.

Functional platelet defects in children with severe chronic ITP as tested with 2 novel assays applicable for low platelet counts.

Immune thrombocytopenia (ITP) is an autoimmune disease with a complex heterogeneous pathogenesis and a bleeding phenotype that is not necessarily correlated to platelet count. In this study, the platelet function was assessed in a well-defined cohort of 33 pediatric chronic ITP patients. Because regular platelet function test cannot be performed in patients with low platelet counts, 2 new assays were developed to determine platelet function: first, the microaggregation test, measuring in platelets isolated from 10 mL of whole blood the platelet potential to form microaggregates in response to an agonist; second, the platelet reactivity assay, measuring platelet reactivity to adenosine diphosphate (ADP), convulxin (CVX), and thrombin receptor activator peptide in only 150 µL of unprocessed whole blood. Patients with a severe bleeding phenotype demonstrated a decreased aggregation potential upon phorbol myristate acetate stimulation, decreased platelet degranulation following ADP stimulation, and a higher concentration of ADP and CVX needed to activate the glycoprotein IIbIIIa complex compared with patients with a mild bleeding phenotype. In conclusion, here we have established 2 functional tests that allow for evaluation of platelet function in patients with extremely low platelet counts (<10(9)). These tests show that platelet function is related to bleeding phenotype in chronic ITP.

Risk stratification of patients with pulmonary embolism based on pulse rate and D-dimer concentration.

To enable outpatient treatment of a selected group of patients with pulmonary embolism (PE), insight in the determinants of adverse clinical outcome is warranted. We have identified risk factors for serious adverse events (SAE) within the first 10 days of acute PE. We have retrospectively analysed data of 440 consecutive patients with acute PE. Collected data included age, gender, medical history, blood pressure, pulse rate and D-dimer concentration. The variables associated with SAE in the first 10 days in univariate analysis (p<0.15) have been included in a multivariate logistic regression model (backward conditional, p out >0.10). In 440 patients with acute PE, 20 SAEs occurred in a 10-day follow-up period. Pulse rate > or = 100 beats per minute (bpm) (OR, 6.85; 95%CI 1.43-32.81) and D-dimer concentration > or = 3,000 microg/ml (OR, 5.51; 95%CI 0.68-44.64) were significantly related to the SAEs. All SAEs were predicted by a pulse rate > or = 100 bpm and/or a D-dimer concentration > or = 3,000 microg/ml. Older age, gender, history of venous thromboembolism (VTE), heart failure, chronic obstructive pulmonary disease, cancer or a systolic blood pressure < 90 mm Hg had no significant influence on short term SAEs. Pulse rate and D-dimer concentration can be used to identify patients with acute PE, who are at risk for adverse clinical outcome during the first 10 days of hospitalisation. Outpatient treatment of PE-patients with a pulse rate > or = 100 bpm and/or a D-dimer concentration > or = 3,000 microg/ml has to be discouraged.