Analytical validation of quantitative immunohistochemical assays of tumor infiltrating lymphocyte biomarkers.

Tumor infiltrating lymphocytes (TIL), especially T-cells, have both prognostic and therapeutic applications. The presence of CD8+ effector T-cells and the ratio of CD8+ cells to FOXP3+ regulatory T-cells have been used as biomarkers of disease prognosis to predict response to various immunotherapies. Blocking the interaction between inhibitory receptors on T-cells and their ligands with therapeutic antibodies including atezolizumab, nivolumab, pembrolizumab and tremelimumab increases the immune response against cancer cells and has shown significant improvement in clinical benefits and survival in several different tumor types. The improved clinical outcome is presumed to be associated with a higher tumor infiltration; therefore, it is thought that more accurate methods for measuring the amount of TIL could assist prognosis and predict treatment response. We have developed and validated quantitative immunohistochemistry (IHC) assays for CD3, CD8 and FOXP3 for immunophenotyping T-lymphocytes in tumor tissue. Various types of formalin fixed, paraffin embedded (FFPE) tumor tissues were immunolabeled with anti-CD3, anti-CD8 and anti-FOXP3 antibodies using an IHC autostainer. The tumor area of stained tissues, including the invasive margin of the tumor, was scored by a pathologist (visual scoring) and by computer-based quantitative image analysis. Two image analysis scores were obtained for the staining of each biomarker: the percent positive cells in the tumor area and positive cells/mm2 tumor area. Comparison of visual vs. image analysis scoring methods using regression analysis showed high correlation and indicated that quantitative image analysis can be used to score the number of positive cells in IHC stained slides. To demonstrate that the IHC assays produce consistent results in normal daily testing, we evaluated the specificity, sensitivity and reproducibility of the IHC assays using both visual and image analysis scoring methods. We found that CD3, CD8 and FOXP3 IHC assays met the fit-for-purpose analytical acceptance validation criteria and that they can be used to support clinical studies.

Ventilator-induced coagulopathy in experimental Streptococcus pneumoniae pneumonia.

Pneumonia, the main cause of acute lung injury, is characterised by a local pro-inflammatory response and coagulopathy. Mechanical ventilation (MV) is often required. However, MV can lead to additional injury: so-called ventilator-induced lung injury (VILI). Therefore, the current authors investigated the effect of VILI on alveolar fibrin turnover in Streptococcus pneumoniae pneumonia. Pneumonia was induced in rats, followed 48 h later by either lung-protective MV (lower tidal volumes (LV(T)) and positive end-expiratory pressure (PEEP)) or MV causing VILI (high tidal volumes (HV(T)) and zero end-expiratory pressure (ZEEP)) for 3 h. Nonventilated pneumonia rats and healthy rats served as controls. Thrombin-antithrombin complexes (TATc), as a measure for coagulation, and plasminogen activator activity, as a measure of fibrinolysis, were determined in bronchoalveolar lavage fluid (BALF) and serum. Pneumonia was characterised by local (BALF) activation of coagulation, resulting in elevated TATc levels and attenuation of fibrinolysis compared with healthy controls. LV(T)-PEEP did not influence alveolar coagulation or fibrinolysis. HV(T)-ZEEP did intensify the local procoagulant response: TATc levels rose significantly and levels of the main inhibitor of fibrinolysis, plasminogen activator inhibitor-1, increased significantly. HV(T)-ZEEP also resulted in systemic elevation of TATc compared with LV(T)-PEEP. Mechanical ventilation causing ventilator-induced lung injury increases pulmonary coagulopathy in an animal model of Streptococcus pneumoniae pneumonia and results in systemic coagulopathy.

Hemangiopericytoma of the sella mimicking pituitary adenoma: case report and review of the literature.

OBJECTIVE: Hemangiopericytoma (HPC) is a potentially malignant vascular neoplasm that in rare cases presents as a primary intracranial lesion, where most often it is meningeal in origin. Hemangiopericytoma arising within the sella turcica is an even more sporadic event. To our knowledge, only 9 cases of HPC presenting as a sellar or suprasellar mass have been reported in the literature. Often, these cases can mimic and be mistaken for a pituitary adenoma. MATERIAL AND METHODS: We report a case of an 18-year-old woman presenting with a sellar mass which was thought both clinically and radiologically to be a pituitary adenoma. RESULTS: Based on histologic, immunohistochemical and electron-microscopic studies, the diagnosis of sellar HPC was made. CONCLUSION: Hemangiopericytoma should be considered in the differential diagnosis of sellar or suprasellar masses.

Anaplastic large cell lymphomas presented as bone lesions: a clinicopathologic study of six cases and review of the literature.

Non-Hodgkin's lymphomas uncommonly present as bone lesions. Most of these tumors are diffuse large B-cell lymphomas. Anaplastic large cell lymphoma (ALCL) presented as bone lesions is exceedingly rare. In this study, we describe six cases of ALCL that presented as solitary or multiple bone lesions. The average patient age was 33 years (range, 4 to 63 years) and the male to female ratio was 2:1. Fever and localized bone pain were the most frequent presenting symptoms. Radiologic examinations revealed osteolytic lesions in all cases, with three (50%) being multiple lesions and five (83%) involving the axial bones. All patients were initially assessed to have only bone involvement. Staging studies revealed mild cervical lymphadenopathy in one patient and no evidence of extraskeletal disease in the other five patients. Histologically, there was diffuse infiltration of one or more bones by large pleomorphic lymphoma cells. Immunohistochemical studies showed all six neoplasms were positive for CD30, EMA, and granzyme B. One case was of T-cell lineage, positive for CD3. One case was positive for the T-cell-associated antigen CD4. The remaining four cases were of null-cell type. In-situ hybridization for EBV was performed in five cases; all were negative. Despite the relatively low International Prognostic Index (IPI) of these patients (mean, 1.67; range, 1 to 3), the overall prognosis was relatively poor: three of six died of disease within 2 years of diagnosis, and two of six were alive with evidence of disease (follow-up, 6 mo to 2 years). Thus, compared to their nodal counterparts, ALCLs that present as bone lesions are distinguished by their uniform expression of EMA and granzyme B, and a relatively poor clinical outcome. Our results also suggest that ALK-1 expression in this clinical setting is not a favorable prognostic indicator.

Flow cytometric detection of CD79a expression in T-cell acute lymphoblastic leukemias.

We evaluated the lineage specificity of CD79a in acute leukemias using 3-color flow cytometry in 58 consecutive cases. A panel of cell-surface antigens, including myeloid-associated markers, B-cell-associated markers, and T-cell-associated markers, was used. All cases of acute myeloid leukemia were CD79a-, whereas all cases of B-lineage acute lymphoblastic leukemia (ALL) were CD79a+. Three of 8 cases of T-cell ALL showed variable CD79a expression, indicating the presence of a blast subset expressing a relatively high level of CD79a. We investigated the clinical and pathologic characteristics of these 3 cases. All 3 cases had L1 or L2 morphology and expressed surface CD3. None of the other B-cell-associated markers were positive, although 1 case expressed CD13 and CD33. Uncommon random karyotypic abnormalities were identified in all 3 cases. Molecular studies demonstrated monoclonal gene rearrangement of T-cell receptor gamma in 2 of 3 cases. All 3 patients were 18 years old or younger; 1 patient did not enter remission, and 1 had disease relapse in 8 months. Our findings provide further support for the existence of a subset of T-cell ALL coexpressing CD3 and CD79a. Further study of the clinical and biologic significance of this subset may be warranted.