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Objective: To assess the capability of seven reference medical laboratories to detect BCR::ABL1 p210 transcription levels and to compare the results among those laboratories. Methods: The interlaboratory comparison was carried out in two stages. The samples were prepared by the reference laboratory. The quantitative values of BCR::ABL1 p210 of the comparison samples covered 0.001%-0.01%, 0.01%-0.1%, 0.1%-1%, 1%-10% and>10% in each stage. Real-time quantitative PCR (RT-PCR) and dPCR (digital PCR) were used to examine the samples. The conversion factor (CF) was calculated and validated for each laboratory. Results: In the RT-PCR comparison, one laboratory was failed to detect BCR::ABL1 p210 in fourteen samples at the first stage. The results of the other six laboratories were qualified with the bias <±1.2 folds (-0.133-0.338) and 95% limits of agreement within ±5 folds (upper limit 0.147-0.785, lower limit -0.770--0.109), and the corresponding CF values were calculated and validated. In the dPCR comparison, one laboratory did not report results at the second stage. The results of the other six laboratories were qualified with the bias <±1.2 folds (-0.026-0.267) and 95% limits of agreement within±5 folds (upper limit 0.084-0.991, lower limit -0.669--0.135), and the corresponding CF values were calculated and validated. The samples with BCR::ABL1 p210 quantitative values of 0.01%-0.1%, 0.1%-1%, 1%-10% and >10% could be detected by both RT-PCR and qPCR. When the quantitative value of BCR::ABL1 p210 was 0.001%-0.01%, the detection rate of dPCR was higher than that of RT-PCR (85.56% vs. 68.00%). Conclusions: A good consistency is present among various laboratories. The quantitative value of BCR::ABL1 p210 is comparable among laboratories as shown by the CF value conversion. For quantitative detection of BCR::ABL1 p210 deep molecular reaction, dPCR has a higher positive detection rate and more advantages than RT-PCR. To ensure the accuracy and reproducibility of the BCR::ABL1 p210 test, it is imperative for every laboratory to enhance their daily quality control practices.

Objective: To investigate the mutational features of the immunoglobulin heavy chain variable region (IgHV) gene in patients with chronic lymphocytic leukemia (CLL) using immunophenotypic and molecular genetic methods. Methods: The laboratory results of 266 CLL patients who underwent IgHV gene examination at Sino-US diagnostics laboratory from February 2020 to February 2021 were analyzed for the IgVH mutational status and presence of specific IgVH fragments. In addition, their immunophenotypic, molecular, chromosomal karyotypic, and FISH profiles were investigated and correlated with the IgVH mutational status. Results: Among 266 patients, 172 were male and 94 were female, with a media age of 67 years (20-82 years).There were more patients with mutated IgHV (m-IgHV) than unmutated IgHV (un-IgHV) (69.2%∶30.8%). There was association of VH family and the presence of gene fragments: the overall incidence of VH families including VH3 family (142/266, 53.4%), VH4 family (75/266, 28.2%), and VH1 family (34/266, 12.8%) was about 95%, among which the proportion of VH4-34 (26/266, 9.8%), VH3-23 (25/266, 9.4%), VH3-7 (24/266, 9.0%), and VH4-39 (16/266, 6.0%) was about 35%. VH3-20 and VH3-49 only occurred in un-IgHV ( P <0.05). In addition, the expression rates of CD38 (26.3% vs. 3.0%), CD79b (71.1%∶45.5%) and 11q deletion (25.5%∶5.3%) were higher in un-IgHV, and single trisomy 12 (37.9%∶5.6%) were more commonly found in m-IgHV ( P <0.05). MYD88 was one of the major mutation genes in m-IgHV, while ATM had the highest mutation rate in un-IgHV. Conclusion: CLL patients have differential expression in terms of IgHV gene mutations, correlating to their immunophenotype and genetics characteristics.

Objective: To analyze the genetic landscape of 52 fusion genes in patients with de novo acute lymphoblastic leukemia (ALL) and to investigate the characteristics of other laboratory results. Methods: The fusion gene expression was retrospectively analyzed in the 1 994 patients with de novo ALL diagnosed from September 2016 to December 2020. In addition, their mutational, immunophenotypical and karyotypical profiles were investigated. Results: In the 1 994 patients with ALL, the median age was 12 years (from 15 days to 89 years). In the panel of targeted genes, 15 different types of fusion genes were detected in 884 patients (44.33%) and demonstrated a Power law distribution. The frequency of detectable fusion genes in B-cell ALL was significantly higher than that in T-cell ALL (48.48% vs 18.71%), and fusion genes were almost exclusively expressed in B-cell ALL or T-cell ALL. The number of fusion genes showed peaks at<1 year, 3-5 years and 35-44 years, respectively. More fusion genes were identified in children than in adults. MLL-FG was most frequently seen in infants and TEL-AML1 was most commonly seen in children, while BCR-ABL1 was dominant in adults. The majority of fusion gene mutations involved signaling pathway and the most frequent mutations were observed in NRAS and KRAS genes. The expression of early-stage B-cell antigens varied in B-cell ALL patients. The complex karyotypes were more common in BCR-ABL1 positive patients than others. Conclusion: The distribution of fusion genes in ALL patients differs by ages and cell lineages. It also corresponds to various gene mutations, immunophenotypes, and karyotypes.

Objective: To investigate the clinicopathologic features of patients with high-grade B-cell lymphomas (HGBL) that have rearrangements of MYC, bcl-6 and bcl-2. Methods: One hundred and fifty-eight B-cell lymphomas patients from Institute of Hematology and Blood Diseases Hospital from January 2016 to April 2017 were detected by fluorescence in situ hybridization (FISH) with double color split-apart probes. Results: Among 158 B-cell lymphomas, 3 cases with MYC, bcl-2 and bcl-6 rearrangements were identified, 1 of which also had CCND1/IgH translocation. All three patients were of older age, with poor prognostic parameters, multiple organs involvements, elevated LDH and advanced-tumor stage. Two of the three patients were treated with high-intensity chemotherapy and had no remission with an overall survival of 9 months and 11 months respectively. One patient had follow-up with no treatment. Histologically, all three cases showed a spectrum of morphologic features. Although initially categorized as lymphoblastic lymphoma, diffuse large lymphoma and mantle cell lymphoma respectively, two cases were associated with germinal center B-cell (GCB) immunophenotype and 1 case with non-GCB immunophenotype. They had a high proliferation index as assessed by immunostaining for Ki-67 (60%-90%). Conclusions: MYC(+) bcl-2(+) bcl-6(+) HGBL is an aggressive disease with multiple organ involvement, high serum LDH levels, advanced stage disease, poor prognosis and shorter patient survival. The diagnosis should be made by histopathology combined with FISH analysis. Its separation from other types of B cell large cell lymphoma is of clinical importance.

Objective: To study the clinicopathologic features of plasma cell myeloma(PCM) with bone marrow fibrosis (MF). Methods: The clinicopathologic data of 175 cases of newly diagnosed PCM patients were retrospectively analyzed. Based on reticular fiber staining, these cases were divided into PCM-MF and non-PCM-MF groups. Results: Sixty-three cases were PCM-MF(36%), 112 were non-PCM-MF (64%). No statistical difference in gender, age, hemoglobin level, platelet counts, the classification of immunoglobulin, ISS staging, immunohistochemical phenotypes and genetic features was found between PCM-MF and non-PCM-MF groups ( P >0.05). Compared to non-PCM-MF group, lactate dehydrogenase (LDH)level and renal impairmentrate were higher in PCM-MF group ( P <0.05). The degree of bone marrow hyperplasia, the percentage of myeloma cells and cells with plasmablastic morphology were significantly higher in PCM-MF group( P <0.05). Conclusion: The higher LDH level, renal impairment rate, and more significant bone marrow hyperplasia, proliferation of plasma cells and plasmablastic myeloma cells infiltration indicate poor prognosis of PCM-MF patients.

Objective: To characterize the molecular profile in patients with Ph negative myeloproliferative neoplasms (MPN) by exploring 49 gene mutations., Methods: Targeted gene sequencing were performed to analyze 49 MPN-associated genes in 51 patients with Ph negative MPN, of which CARL (exon 9), NPM1 (exon 12) and CEBPA (TAD, BZIP domains) were investigated by using Sanger sequencing simultaneously, while FLT3-ITD was assessed by PCR method., Results: Mutations were detected in 73.5% (36/49) of genes, and the mutational rates of JAK2-V617F, CALR (exon 9) and MPL were 60.8%(31/51), 7.8%(4/51) and 7.8%(4/51) respectively, whereas the mutational rates of ASXL1, SETBP1, and SF3B1 were around 10%. In addition, 96.1% (49/51) of patients harbored at least one mutation, and more than half of the patients (52.9%, 27/51) possessed 3 or 4 gene mutations. The amount of gene mutations was significantly higher in patients with JAK2-V617F mutation than those without JAK2-V617F or CALR (exon 9) mutation (P<0.05). The last finding was that there was no statistically significant difference in the amount of mutations among four MPN subtypes (PV, ET, PMF, and MPN-U)., Conclusion: Most patients with Ph negative MPN possesses three or more gene mutations, with various mutational profiles.

Objective: To investigate pathologic and differential diagnostic features of pediatric Burkitt lymphoma (BL)., Methods: A total of 20 cases of pediatric BL were retrospectively reviewed for their clinical and pathologic profiles. Bone marrow aspiration specimens were available in all cases and bone marrow biopsies were available for immunohistochemical study in 18 cases. Flow cytometry study was available in 16 cases. MYC translocation by FISH method was performed in 11 cases., Results: Atypical lymphocytes with cytoplasmic vacuoles were found in bone marrow smears in all 20 cases and peripheral blood films in all 19 available cases. The bone marrow biopsies showed infiltration by uniform medium-sized atypical lymphocytes with multiple small nucleoli but without the starry-sky pattern in all 18 cases. Immunohistochemistry showed the following results in all 18 cases: positive for CD20, PAX-5, CD10, CD34 and TdT, but negative for bcl-2 and CD3 with Ki-67 > 95%.Flow cytometry showed CD19+CD20+CD10+FMC7+CD22+TdT-CD3- in 16 cases, including κ+ in 8 cases, λ+ in 7 cases, and κ-λ- in 1 case. MYC gene rearrangement by FISH was observed in 10 of the 11 cases., Conclusions: The histopathology of BL is distinct, including atypical lymphocytes with cytoplasmic vacuoles in bone marrow aspirate, lack of starry-sky patternin bone marrow biopsy. Generally, the diagnosis should be made with a combined immunophenotype and FISH approach. Pediatric BL must be distinguished from DLBCL and B-cell lymphoma, unclassifiable, which has intermediate features between DLBCL and Burkitt lymphoma.