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Many hyperplasias and lymphomas of marginal zone B-cells are associated with infection. We identified six children and one adolescent with cervical lymphadenopathy showing prominent polyclonal nodal marginal zone hyperplasia ( pNMZH) and four adolescents with monoclonal paediatric nodal marginal zone lymphoma ( pNMZL). The clonality status was assessed using BIOMED-2- IG PCR analysis. Haemophilus influenzae was identified in all six cases of pNMZH that could be tested by direct culture ( N = 3) or a very sensitive PCR for the H. influenzae gyrase gene in frozen materials ( N = 5). H. influenzae was not detected in three pNMZLs and 28 non-specific reactive cervical lymph nodes of age-matched controls, except for a single control node that was obtained during oropharyngeal surgery for a cleft palate showing very low copy numbers of H. influenzae. pNMZH patients were younger than pNMZL patients (median age 12 versus 21 years). pNMZH showed a prominent nodular appearance with variable fibrosis without acute inflammation. Within the nodules, the expanded germinal centres and variably sized marginal zones were colonized by activated B-cells with weak expression of IgD and lack of CD10 and/or BCL6 expression. Some areas showed skewed light chain expression in plasma cells (4/5 cases lambda). In four cases tested, this was confirmed by flow cytometry for surface Ig (3/4 cases lambda). In contrast, pNMZL showed more extensive expansion of marginal zones by centrocytoid cells and often expression of BCL2 protein. Several H. influenzae strains are known to interact with the constant part of IgD on human B-cells, leading to their polyclonal proliferation and activation. We speculate that in vivo stimulation of IgD+ marginal zone B-cells by this bacterium may be implicated in this particular lymphadenopathy that should be distinguished from monoclonal pNMZL. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Epstein-Barr virus lymphoproliferative disease (EBV-LPD) following allogeneic stem cell transplantation (allo-SCT) has a poor prognosis. We used a sensitive real-time polymerase chain reaction (PCR) assay for quantitative detection of EBV-DNA in plasma and serially measured EBV-DNA levels to assess the response to treatment in allo-SCT recipients with EBV-LPD. Fourteen allo-SCT recipients with EBV-LPD who received a T cell-depleted (TCD) sibling (n = 5) or matched unrelated donor (n = 9) graft were monitored from the time of EBV-LPD diagnosis, during therapy and assessment of clinical response. Seven patients had complete responses of EBV-LPD to therapy, of whom 21% (3 out of 14) survived beyond 6 months from EBV-LPD diagnosis. Clinically responding patients showed a rapid decline of EBV-DNA plasma levels within 72 h from the start of therapy. In contrast, all clinical non-responders showed an increase of EBV-DNA levels. Absolute EBV-DNA levels at the time of EBV-LPD diagnosis did not predict for response, but the pattern of EBV-DNA levels within 72 h from the start of therapy (> 50% decrease versus increase) strongly predicted for clinical response (P = 0·001). Quantitative monitoring of EBV-DNA levels from the start of and during therapy for EBV-LPD rapidly and accurately predicts for response to therapy as early as within 72 h. It may thus provide a powerful tool to adjust and select treatment in individuals with EBV-LPD following allo-SCT. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PHT) occurs in approximately 30% of adults with sickle cell disease (SCD) and is an independent risk factor for early death. In this study, we aimed to determine the value of general laboratory testing, plain chest radiography, electrocardiography (ECG), high-resolution computer tomography (HRCT) of the thorax, pulmonary function testing, and plasma N-terminal brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP) in patients with SCD-related PHT. A cohort of 85 ambulatory sickle cell patients were prospectively screened for PHT with echocardiography (defined as a tricuspid regurgitation flow velocity of > or =2.5 m/sec). All patients were systematically evaluated by the aforementioned diagnostic tests comparing patients with and without PHT. The prevalence of PHT was 41% in HbSS/HbSbeta(0)-thalassemia patients and 13% in HbSC/HbSbeta(+)-thalassemia patients. No statistically significant differences were detected in ECG, chest radiography, HRCT, and pulmonary function testing between patients with and without PHT. The degree of anemia and renal dysfunction, but not the presence of PHT, were the most important determinants of plasma (NT-pro)BNP levels. The performed imaging and functional studies do not seem to be of value in identifying etiological conditions (such as airflow obstruction or parenchymal lung disease) nor do they offer clues to the presence of mild PHT in SCD., (Copyright 2008 Wiley-Liss, Inc.)