Search

Importance: Ovine pulmonary adenomatosis (OPA) and maedi-visna disease (MVD) are chronic and progressive infectious diseases in sheep caused by Jaagsiekte sheep retrovirus (JSRV) and maedi-visna virus (MVV), respectively. Objective: To investigate the pathological changes and conduct viral gene analysis of OPA and MVD co-occurrence in Inner Mongolia, China. Methods: Using gross pathology, histopathology, immunohistochemistry, ultrastructural pathology, PCR, and sequence analysis, we investigated the concurrent infection of JSRV and MVV in 319 Dorper rams slaughtered in a private slaughterhouse in Inner Mongolia, in 2022. Results: Of the 319 rams included, 3 showed concurrent JSRV and MVV infection. Gross lung pathology showed diffuse enlargement, consolidation, and greyish-white miliary nodules on the lung surface; the trachea was filled with a white foamy fluid; hilar and mediastinal lymph nodes were significantly enlarged. Histopathology results revealed typical OPA and MVD lesions in the lung tissue. Immunohistochemical results were positive for JSRV envelope protein (Env) in the tumor cells and MVV CA in alveolar macrophages. Transmission electron microscopy showed several virions and autophagosomes in the lung tissue, severely damaged mitochondria, and the induced mitophagy. Nucleotide sequences obtained for JSRV env and MVV gag showed the highest homology with the Inner Mongolian strains of JSRV env (JQ837489) and MVV gag (MW248464). Conclusions and Relevance: Our study confirmed that OPA and MVD co-occurrence and identified the pathological changes in Inner Mongolia, China, thereby providing references for the identification of concurrent JSRV and MVV infections. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the efficacy and safety of trastuzumab biosimilar (HLX02) in combination with pertuzumab and chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) after progression of trastuzumab. Materials and Methods: In this prospective, single-arm, phase II study, patients with HER2-positive MBC after progression of trastuzumab received pertuzuamb, HLX02, and chemotherapy in Beijing Cancer Hospital from March 2020 to December 2022. The primary endpoint was progression-free survival (PFS), and secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. The study was registered with ClinicalTrials.gov (NCT05188495). Results: A total of 45 patients were included in this study. Twelve patients (26.7%) were treated in second-line and 33 patients (73.3%) were in third-line and later setting. Eighty percent and 15.5% patients had previously received pyrotinib/lapatinib and T-DM1, respectively. With a median follow-up of 24.4 months (range, 1.2 to 43.9 months), the median PFS was 7.6 months (95% confidence interval, 4.3 to 10.9), OS was not reached, the ORR was 31.1%, and DCR was 91.1%. The treatment was well tolerated. Conclusion The combination of trastuzumab biosimilar HLX02, pertuzumab, and chemotherapy exhibited promising efficacy and a favorable safety profile as second- and beyond-line treatment in HER2-positive MBC. [ABSTRACT FROM AUTHOR]

Accurately distinguishing HER2-2+ tumors from HER2-0/1+ tumors via immunohistochemistry (IHC) is still very challenging. HER2 IHC 2+ is considered to indicate moderate expression and is easier to distinguish, with more reliable results in previous and current clinical practice. We focused on HER2-2+ patients and evaluated the switch in HER2 status between primary and paired recurrent disease patients to evaluate the discordance of HER2-2+ expression. We included patients who were HER2-2+ of primary or rebiopsy tumor samples, to evaluate the evolution of HER2-2+ expression. In the cohort with a total of 159 patients with HER2-2+ expression in either primary tumor or locoregional/distant metastasis samples, 44.0% had HER2-2+ in primary tumor and 88.8% in recurrent disease. Among patients with primary and recurrent HER2-2+ breast cancers, 18.5% and 15.2% of the patients, respectively, had HER2 gene amplification via ISH. The overall rate of discordance in HER2 IHC results was 67.1%. Among primary HER2-2+ patients, 74.6% were maintained in the HER2-2+ cohort at the recurrence. The discordance was mostly driven by patients switching from HER2-2+ to HER2-1+ (64.7%). Among HER2-2+ recurrent patients, discordance in the IHC results was mostly driven by switching from HER2-0 to HER2-2+ (47.1%). When HER2-low was added to the analysis, the overall rate of HER2 discordance was 40.4%. The proportion of patients with discordant HER2 expression was significantly greater among HR-positive patients than negative patients (44.1% vs. 21.7%, p=0.062). HER2 expression in primary and recurrent breast cancer samples was highly unstable. Discordance was more frequently observed in the HR-positive population. [ABSTRACT FROM AUTHOR]