The role of lymphoid tissue SPARC in the pathogenesis and response to treatment of multiple myeloma.

Background: Despite the significant progress in the treatment of multiple myeloma (MM), the disease remains untreatable and its cure is still an unmet clinical need. Neoplastic transformation in MM is initiated in the germinal centers (GCs) of secondary lymphoid tissue (SLT) where B cells experience extensive somatic hypermutation induced by follicular dendritic cells (FDCs) and T-cell signals. Objective: We reason that secreted protein acidic and rich in cysteine (SPARC), a common stromal motif expressed by FDCs at the origin (SLTs) and the destination (BM) of MM, plays a role in the pathogenesis of MM, and, here, we sought to investigate this role. Methods: There were 107 BM biopsies from 57 MM patients (taken at different time points) together with 13 control specimens assessed for SPARC gene and protein expression and compared with tonsillar tissues. In addition, regulation of myeloma-promoting genes by SPARC-secreting FDCs was assessed in in vitro GC reactions (GCRs). Results: SPARC gene expression was confirmed in both human primary (BM) and secondary (tonsils) lymphoid tissues, and the expression was significantly higher in the BM. Sparc was detectable in the BM and tonsillar lysates, co-localized with the FDC markers in both tissues, and stimulation of FDCs in vitro induced significantly higher levels of SPARC expression than unstimulated controls. In addition, SPARC inversely correlated with BM PC infiltration, ISS staging, and ECOG performance of the MM patients, and in vitro addition of FDCs to lymphocytes inhibited the expression of several oncogenes associated with malignant transformation of PCs. Conclusion: FDC-SPARC inhibits several myelomagenic gene expression and inversely correlates with PC infiltration and MM progression. Therapeutic induction of SPARC expression through combinations of the current MM drugs, repositioning of non-MM drugs, or novel drug discovery could pave the way to better control MM in clinically severe and drug-resistant patients.

Classification of Monocytes, Promonocytes and Monoblasts Using Deep Neural Network Models: An Area of Unmet Need in Diagnostic Hematopathology.

The accurate diagnosis of chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML) subtypes with monocytic differentiation relies on the proper identification and quantitation of blast cells and blast-equivalent cells, including promonocytes. This distinction can be quite challenging given the cytomorphologic and immunophenotypic similarities among the monocytic cell precursors. The aim of this study was to assess the performance of convolutional neural networks (CNN) in separating monocytes from their precursors (i.e., promonocytes and monoblasts). We collected digital images of 935 monocytic cells that were blindly reviewed by five experienced morphologists and assigned into three subtypes: monocyte, promonocyte, and blast. The consensus between reviewers was considered as a ground truth reference label for each cell. In order to assess the performance of CNN models, we divided our data into training (70%), validation (10%), and test (20%) datasets, as well as applied fivefold cross validation. The CNN models did not perform well for predicting three monocytic subtypes, but their performance was significantly improved for two subtypes (monocyte vs. promonocytes + blasts). Our findings (1) support the concept that morphologic distinction between monocytic cells of various differentiation level is difficult; (2) suggest that combining blasts and promonocytes into a single category is desirable for improved accuracy; and (3) show that CNN models can reach accuracy comparable to human reviewers (0.78 ± 0.10 vs. 0.86 ± 0.05). As far as we know, this is the first study to separate monocytes from their precursors using CNN.

Prevalence of α-Thalassemia in the Egyptian Population.

Hemoglobinopathies are the most common monogenic diseases in the world, causing many health problems worldwide. In Egypt, thalassemia is the most common cause of chronic hemolytic anemia and correlated with significant morbidity and mortality. One thousand Egyptian newborns were screened to detect α-thalassemia (α-thal) deletions using polymerase chain reaction (PCR)-based DNA analysis of cord blood samples. Ninety-one cases (9.1%) of the studied samples were proved to have at least one of the α genes deleted and 851 cases (85.1%) were normal by PCR analysis, while 58 samples (5.8%) failed to be amplified so further DNA analysis could not be done. In the studied group with α gene deletions, we found different types including silent carriers with only one α-globin gene deleted (3.1%), α-thal trait with two α-globin genes deleted (4.2%), Hb H disease with three α-globin genes deleted (1.8%) and no cases carrying Hb Bart's disease with loss of four α-globin genes. We determined the deletional spectrum of α-thal, which might be used in the future for molecular investigations of the disease in susceptible patients in our population.

MEFV gene mutations in Egyptian children with Henoch-Schonlein purpura.

BACKGROUND: Due to an increased frequency of vasculitis in FMF patients, many investigators have studied MEFV mutations in patients with HSP. The aim of the study is to investigate the frequency and clinical significance of MEFV mutations in Egyptian children with Henoch-Schonlein purpura (HSP). Investigating MEFV mutations in controls may help in estimating the prevalence of MEFV mutation carrier rate in Egyptian children. METHODS: The study enrolled 90 individuals, sixty children with Henoch-Schonlein purpura (HSP), together with 30 sex-and age-matched apparently healthy controls. The entire study group was screened for 12 common MEFV mutations using a reverse hybridization assay of biotinylated PCR products. RESULTS: Patients with HSP had a significantly higher frequency of MEFV mutations (61.7%), when compared to the apparently healthy control population (36.7%). V726A was the most frequent mutation with an allelic frequency of 10.8%. Ninety- one percent of patients with MEFV mutations were heterozygous for one mutation, while 8.1% had a compound heterozygous MEFV gene mutations. The mutation V726A, followed by E148Q, were the leading mutations, present in 16.6% and in 13.3% of controls. CONCLUSIONS: MEFV mutations may be related to HSP susceptibility in children. The mutations were not associated with any clinical and laboratory manifestations. Screening for MEFV mutations in larger number of HSP children may be beneficial to evaluate any possible relationship between certain types of MEFV mutations and HSP, and compare the HSP MEFV mutations to the types of MEFV mutations associated with FMF.

Study of 22 Egyptian patients with Diamond-Blackfan anemia, corticosteroids, and cyclosporin therapy results.

OBJECTIVE: Diamond-Blackfan anemia is a rare congenital hypoproliferative anemia of infancy and early childhood. Treatment with corticosteroids is commonly used, but with limited success. Trials with cyclosporin-A (CSA) are not frequently reported. Therefore, in this study we analyzed our results in the management of this rare disease by different medical treatments. DESIGN: The results of 22 patients diagnosed at our Hematology Center in the New Cairo University Children's Hospital during the period 1991-2001 were retrospectively analyzed. Our patients first received prednisolone (2 mg/kg/d) for different courses according to their response. Since the year 2000, the steroid nonresponders received CSA (3-12 mg/kg/d) for 6 months unless treatment complications developed. RESULTS: The age at the onset of the disease ranged from 1 to 24 months (median: 2.5 months). The mean values of the hemoglobin, the reticulocyte count, and the myeloid/erythroid ratio at the onset of the disease were 4.75 +/- 1.79 g/dL, 0.14 +/- 0.16, and 39.4 +/- 27.08, respectively. Patients received prednisolone from 0.25 to 10 years (median: 2 years). Ten patients were nonresponders (45.5%), and 5 patients (22.7%) responded to corticosteroid therapy. Two of 5 responders are off treatment with a hemoglobin level of >9 g/dL, and 3 of 5 are currently corticosteroid-dependent. Of 10 patients not responding to steroids, 8 received CSA for 6 months. Four patients (50%) responded to CSA therapy. A significant positive association was found between CSA dose and response. CONCLUSION: CSA therapy should be tried in steroid-resistant Diamond-Blackfan anemia patients before blood transfusion or corticosteroid therapy complications are instituted.