MATERIALS AND METHODS: We searched for FL-LP in our institution from 2000 to 2018 and characterised the neoplastic cells by flow cytometry, immunohistochemistry and fluorescence in situ hybridization. Thirteen (6.1%) of 212 FL cases were FL-LP, all de novo neoplasms. The leukaemic cells were small in 12 cases and large in one. All had concurrent FL, mostly (92%; 12/13) low-grade. The single case with large leukaemic cells had a concurrent primary splenic low-grade FL and a double-hit large B-cell lymphoma in the marrow.
RESULTS: CD10 was expressed in the leukaemic cells in 38% (5/13) cases by flow cytometry and in 77% (10/13) cases in tumours (p= 0.0471). IGH/BCL2 reciprocal translocation was identified in 85% (11/13) cases. Most patients were treated with chemotherapy. In a median follow-up time of 36 months, nine patients were in complete remission. The 2- and 5-year survival rates were at 100% and 83%, respectively. In this study, we characterised a series of de novo FL-LP in Taiwan. All patients had concurrent nodal and/or tissue tumours, which might suggest that these patients seek medical help too late.
CONCLUSION: The lower CD10 expression rate by flow cytometry than by immunohistochemistry might be due to different epitopes for these assays. Alternatively, loss of CD10 expression might play a role in the pathogenesis of leukaemic change. The clinical course of FL-LP could be aggressive, but a significant proportion of the patients obtained complete remission with chemotherapy.
METHODOLOGY: Parallel virology was used to investigate the phenotypes of duck and mosquito-derived isolates of TMUV. Molecular biology and bioinformatics methods were employed to investigate the genetic characteristics and evolution of TMUV.
PRINCIPAL FINDINGS: The plaque diameter of duck-derived isolates of TMUV was larger than that of mosquito-derived isolates. The cytopathic effect (CPE) in mammalian cells occurred more rapidly induced by duck-derived isolates than by mosquito-derived isolates. Furthermore, duck-derived isolates required less time to reach maximum titer, and exhibited higher viral titer. These findings suggested that poultry-derived TMUV isolates were more invasive and had greater expansion capability than the mosquito-derived isolates in mammalian cells. Variations in amino acid loci in TMUV E gene sequence revealed two mutated amino acid loci in strains isolated from Malaysia, Thailand, and Chinese mainland compared with the prototypical strain of the virus (MM1775). Furthermore, TMUV isolates from the Chinese mainland had six common variations in the E gene loci that differed from the Southeast Asian strains. Phylogenetic analysis indicated that TMUV did not exhibit a species barrier in avian species and consisted of two lineages: the Southeast Asian and the Chinese mainland lineages. Molecular traceability studies revealed that the recent common evolutionary ancestor of TMUV might have appeared before 1934 and that Malaysia, Thailand and Shandong Province of China represent the three main sources related to TMUV spread.
CONCLUSIONS: The current broad distribution of TMUV strains in Southeast Asia and Chinese mainland exhibited longer-range diffusion and larger-scale propagation. Therefore, in addition to China, other Asian and European countries linked to Asia have used improved measures to detect and monitor TMUV related diseases to prevent epidemics in poultry.