A Multicenter Study of Clinicopathology and Immunohistochemical Distinction between Adult and Pediatric Large B-Cell Lymphoma.

Introduction: Pediatric DLBCL is considered a homogenous group and has superior outcomes compared to adults. This study investigated the clinical pathology and immunohistochemical distinction between adult and pediatric large B-cell lymphoma. Methods: A cross-sectional study of 314 NHLs with the morphology of diffuse pattern, large B-cell, and CD20 expression was investigated. Results: Of 314 cases, there were 6 cases of pleomorphic MCL (all in adults), 19 cases of Burkitt lymphoma (all in children), and 289 cases of DLBCL. Pediatric DLBCL had many striking differences: More frequency in extra-nodal sites; a higher proportion of centroblastic morphology; a predominance of GCB-type; a high proliferation rate; an infrequency of Bcl2 protein expression, and a lack of double-expresser lymphoma. Conclusions: Our study demonstrated the significant biological differences between adult and pediatric DLBCL.

Immunohistochemical expression of anaplastic lymphoma kinase in neuroblastoma and its relations with some clinical and histopathological features.

BACKGROUND: Anaplastic lymphoma kinase (ALK) mutations have been identified as a prominent cause of some familial and sporadic neuroblastoma (NB). ALK expression in NB and its relationship with clinical and histopathological features remains controversial. This study investigated ALK expression and its potential relations with these features in NB. METHODS: Ninety cases of NB at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam from 01/01/2018 to 12/31/2021, were immunohistochemically stained with ALK (D5F3) antibody. The ALK expression and its relations with some clinical and histopathological features were investigated. RESULTS: The rate of ALK expression in NB was 91.1%. High ALK expression (over 50% of tumor cells were positive with moderate-strong intensity) accounted for 65.6%, and low ALK expression accounted for 34.4%. All the MYCN-amplified NB patients had ALK immunohistochemistry positivity, most cases had high ALK protein expression. The undifferentiated subtype of NB had a lower ALK-positive rate than the poorly differentiated and differentiated subtype. The percentages of ALK positivity were significantly higher in more differentiated histological types of NB (p = .024). There was no relation between ALK expression and: age group, sex, primary tumor location, tumor stage, MYCN status, clinical risk, Mitotic-Karyorrhectic Index, prognostic group, necrosis, and calcification. CONCLUSIONS: ALK was highly expressed in NB. ALK expression was not related to several clinical and histopathological features. More studies are needed to elucidate the association between ALK expression and ALK gene status and to investigate disease progression, especially the oncogenesis of ALK-positive NB.

Immunohistochemical expression in idiopathic inflammatory myopathies at a single center in Vietnam.

BACKGROUND: The identification of idiopathic inflammatory myopathies (IIMs) requires a comprehensive analysis involving clinical manifestations and histological findings. This study aims to provide insights into the histopathological and immunohistochemical aspects of IIMs. METHODS: This retrospective case series involved 56 patients diagnosed with IIMs at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, from 2019 to 2023. The histology and immunohistochemical expression of HLA-ABC, HLA-DR, C5b-9, Mx1/2/3, and p62 were detected. RESULTS: We examined six categories of inflammatory myopathy, including immunemediated necrotizing myopathy (58.9%), dermatomyositis (DM; 23.2%), overlap myositis (8.9%), antisynthetase syndrome (5.4%), inclusion body myositis (IBM; 1.8%), and polymyositis (1.8%). The average age of the patients was 49.7 ± 16.1 years, with a female-to-male ratio of 3:1. Inflammatory cell infiltration in the endomysium was present in 62.5% of cases, perifascicular atrophy was found in 17.8%, and fiber necrosis was observed in 42 cases (75.0%). Rimmed vacuoles were present in 100% of cases in the IBM group. Immunohistochemistry showed the following positivity rates: HLA-ABC (89.2%), HLA-DR (19.6%), C5b-9 (57.1%), and Mx1/2/3 (10.7%). Mx1/2/3 expression was high in DM cases. p62 vacuole deposits were noted in the IBM case. The combination of membrane attack complex and major histocompatibility complex I helped detect IIMs in 96% of cases. CONCLUSIONS: The diagnosis of IIMs and their subtypes should be based on clinical features and histopathological characteristics. Immunohistochemistry plays a crucial role in the diagnosis and differentiation of these subgroups.

Characteristics of Immunogenicity against SARS-CoV-2 in a Community-Based Model of Care during the Fourth Wave of COVID-19 Outbreak in Ho Chi Minh City.

PURPOSE: Although some immune protection from close contact with individuals who have coronavirus disease 2019 (COVID-19) has been documented, there is limited data on the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals who were in lockdown with confirmed COVID-19 cases. This study investigated immunogenicity against SARS-CoV-2 in household members and people who lived near home-quarantined patients with COVID-19. MATERIALS AND METHODS: This cross-sectional study was conducted during the community-based care that took place during lockdowns in District 10, Ho Chi Minh City, Vietnam from July to September 2021. SARS-CoV-2 antibody levels were determined in index cases of COVID-19, household contacts, and a no-contact group from the same area. RESULTS: A total of 770 participants were included (355 index cases, 103 household contacts, and 312 no contacts). All index cases were unvaccinated, but >90% of individuals in the household and no-contact groups had received ≥1 vaccine dose. SARS-CoV-2 neutralizing antibodies (Nabs) were present in >77% of unvaccinated index cases versus 64%/65.4% in the household/no-contact groups (p=0.001). Antibody concentrations in unvaccinated index cases were significantly higher than those in household contacts and no contacts, with no difference between the latter groups. In all cases, antibody levels declined markedly ≥6 weeks after infection, and failed to persist beyond this time in the household and no-contact groups. CONCLUSION: Community-based care may have helped to create community immunogenicity, but Nabs did not persist, highlighting a need for vaccination for all individuals before, or from 6 weeks after, infection with SARS-CoV-2.

Intra-Articular Calcaneus Osteoid Osteoma With an Ankle Varus and a Red-Brown Synovial Fluid in the Affected Joint, a Case Report.

Background: Only one article described ankle varus as a typical symptom in the late stage of the intra-articular osteoid osteoma of the calcaneus. And the red-brown color of synovial fluid in the affected joint hasn't been reported. This report shows a patient with intra-articular osteoid osteoma of the calcaneus who had the 2 above symptoms. Case presentation: A 39-year-old man had left ankle pain and the diagnosis was delayed for 20 months. At the late stage, the ankle was gradually varus. In our hospital, the withdrawal of the subtalar joint gave a red-brown synovial fluid. Together with the typical lesion on MRI, the diagnosis of intra-articular osteoid osteoma of the calcaneus was made. An open operation was performed for treatment. In the procedure, the red-brown synovial fluid was exuded. A specimen was harvested for biopsy confirming osteoid osteoma. Conclusions: It is still essential that intra-articular calcaneal osteoid osteoma should be considered in patients with prolonged pain and varus of the ankle. The red-brown synovial may be used as a finding for diagnosis.

A study of pathological characteristics and BRAF V600E status in Langerhans cell histiocytosis of Vietnamese children.

BACKGROUND: Langerhans cell histiocytosis (LCH) is more common in children than adults and involves many organs. In children, the BRAF V600E mutation is associated with recurrent and high-risk LCH. METHODS: We collected paraffin blocks of 94 pediatric LCH patients to detect BRAF V600E mutation by sequencing. The relationship between BRAF V600E status and clinicopathological parameters were also critically analyzed. RESULTS: BRAF V600E mutation exon 15 was detected in 45 cases (47.9%). Multiple systems LCH showed a significantly higher BRAF V600E mutation rate than a single system (p=.001). No statistical significance was evident for other clinical characteristics such as age, sex, location, risk organs involvement, and CD1a expression. CONCLUSIONS: In Vietnamese LCH children, the proportion of BRAF V600E mutational status was relatively high and related to multiple systems.

Activated platelet-rich plasma improves adipose-derived stem cell transplantation efficiency in injured articular cartilage.

INTRODUCTION: Adipose-derived stem cells (ADSCs) have been isolated, expanded, and applied in the treatment of many diseases. ADSCs have also been used to treat injured articular cartilage. However, there is controversy regarding the treatment efficiency. We considered that ADSC transplantation with activated platelet-rich plasma (PRP) may improve injured articular cartilage compared with that of ADSC transplantation alone. In this study, we determined the role of PRP in ADSC transplantation to improve the treatment efficiency. METHODS: ADSCs were isolated and expanded from human adipose tissue. PRP was collected and activated from human peripheral blood. The effects of PRP were evaluated in vitro and in ADSC transplantation in vivo. In vitro, the effects of PRP on ADSC proliferation, differentiation into chondrogenic cells, and inhibition of angiogenic factors were investigated at three concentrations of PRP (10%, 15% and 20%). In vivo, ADSCs pretreated with or without PRP were transplanted into murine models of injured articular cartilage. RESULTS: PRP promoted ADSC proliferation and differentiation into chondrogenic cells that strongly expressed collagen II, Sox9 and aggrecan. Moreover, PRP inhibited expression of the angiogenic factor vascular endothelial growth factor. As a result, PRP-pretreated ADSCs improved healing of injured articular cartilage in murine models compared with that of untreated ADSCs. CONCLUSION: Pretreatment of ADSCs with PRP is a simple method to efficiently apply ADSCs in cartilage regeneration. This study provides an important step toward the use of autologous ADSCs in the treatment of injured articular cartilage.