Importance Four assays have been registered with the FDA to detect PD-L1 to enrich for patient response to anti-PD-1/PD-L1 therapies. The tests use four separate PD-L1 antibodies on two separate staining platforms and have their own scoring systems which raises questions about their similarity and potential cross-utilization. Objective We compared the performance of four PD-L1 platforms, including two FDA-cleared assays and two laboratory developed tests (LDTs). Design Four serial histology sections from 90 archival NSCLCs were distributed to three sites that performed the following IHCs: 1) 28-8 antibody on Dako Link 48; 2) 22c3 antibody on Dako Link 48; 3) SP142 antibody on Ventana Benchmark; and 4) E1L3N antibody on Leica Bond. Slides were scanned and scored by thirteen pathologists by estimating the percentage of malignant and immune cells expressing PD-L1. Intraclass correlation coefficients (ICC) and paired and mixed effects statistical analyses were performed to compare antibodies and pathologists scoring of tumor and immune cells. Results The SP142 Ventana assay was an outlier with a significantly lower mean score of PD-L1 expression in both tumor and immune cells. Pairwise comparisons showed the 28-8 and E1L3N were not significantly different, but that 22c3 showed a slight but statistically significant reduction in tumor cell labeling. Evaluation of ICC between antibodies to quantify inter-assay variability using the average of thirteen pathologists scores for tumor shows very high concordance between antibodies for tumor cell scoring (0.813) and lower levels of concordance for immune cell scoring (0.277). When examining inter-pathologists variability for any single antibody, the concordance between pathologists’ reads for tumor ranged from ICC of 0.83 to 0.88 for each antibody while the ICC from immune cells for each antibody ranged from 0.17 to 0.23. Conclusions The assay using the SP142 antibody is a clear outlier detecting significantly less tumor cell and immune cell PD-L1 expression. Antibody 22c3 shows slight yet statistically significantly lower staining than either 28-8 or E1L3N, but this significance is only detected when using the average of thirteen pathologist scores. Pathologists show excellent concordance when scoring tumor cells stained with any antibody, but poor concordance for scoring immune cell staining.

Inflammatory myofibroblastic tumors (IMTs) are neoplastic mesenchymal proliferations featuring an inflammatory infiltrate composed primarily of lymphocytes and plasma cells. The myofibroblastic cells in some IMTs contain chromosomal rearrangements involving the ALK receptor tyrosine-kinase locus region (chromosome band 2p23). ALK-which is normally restricted in its expression to neural tissues-is expressed strikingly in the IMT cells with 2p23 rearrangements. We now report a recurrent oncogenic mechanism, in IMTs, in which tropomyosin (TPM) N-terminal coiled-coil domains are fused to the ALK C-terminal kinase domain. We have cloned two ALK fusion genes, TPM4-ALK and TPM3-ALK, which encode ϳ95-kd fusion oncoproteins characterized by constitutive kinase activity and tyrosylphosphorylation. Immunohistochemical and molecular correlations, in other IMTs, implicate non-TPM ALK oncoproteins that are predominantly cytoplasmic or predominantly nuclear, presumably depending on the subcellular localization of the ALK fusion partner. Notably, a TPM3-ALK oncogene was reported recently in anaplastic lymphoma, and TPM3-ALK is thereby the first known fusion oncogene that transforms, in vivo, both mesenchymal and lymphoid human cell lineages. (Am J Pathol 2000, 157:377-384)

No abstract

Clin. Invest. 1994.93:1298-1306

IHC scoring correlates with FISH and may be a useful algorithm in testing ALK+ by FISH in non-small cell lung carcinoma, similar to human epidermal growth factor-2 testing in breast cancer. Further study is needed to validate this approach.

Pulmonary vascular medial hypertrophy in primary pulmonary hypertension (PPH) is mainly caused by increased proliferation and decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Mutations of the bone morphogenetic protein (BMP) receptor type II (BMP-RII) gene have been implicated in patients with familial and sporadic PPH. The objective of this study was to elucidate the apoptotic effects of BMPs on normal human PASMCs and to examine whether BMP-induced effects are altered in PASMCs from PPH patients. Using RT-PCR, we detected six isoforms of BMPs (BMP-1 through -6) and three subunits of BMP receptors (BMP-RIa, -RIb, and -RII) in PASMCs. Treatment of normal PASMCs with BMP-2 or -7 (100-200 nM, 24-48 h) markedly increased the percentage of cells undergoing apoptosis. The BMP-2-mediated apoptosis in normal PASMCs was associated with a transient activation or phosphorylation of Smad1 and a marked downregulation of the antiapoptotic protein Bcl-2. In PASMCs from PPH patients, the BMP-2- or BMP-7-induced apoptosis was significantly inhibited compared with PASMCs from patients with secondary pulmonary hypertension. These results suggest that the antiproliferative effect of BMPs is partially due to induction of PASMC apoptosis, which serves as a critical mechanism to maintain normal cell number in the pulmonary vasculature. Inhibition of BMP-induced PASMC apoptosis in PPH patients may play an important role in the development of pulmonary vascular medial hypertrophy in these patients.

Immunoglobulin (Ig)G4-related sclerosing disease (ISD) (also called IgG4-related systemic disease, IgG4-related disease or hyper-IgG4 disease) is a recently described systemic fibroinflammatory disease associated with elevated circulating levels of IgG4.Although initial descriptions of this disorder focused on its pancreatic presentation (autoimmune pancreatitis), it has become apparent that ISD is a systemic disease with many facets. The lesion of ISD is characterised by lymphoplasmacytic inflammation, fibrosis, phlebitis and increased numbers of IgG4-positive plasma cells. The disease can either be localised to one or two organs, or be present with diffuse multi-organ disease. Furthermore, lesions in different organs can present simultaneously or metachronously. In the thorax, lesions associated with ISD have been described in the lung parenchyma, airways and pleura, as well as the mediastinum.Data published to date suggest that ISD may account for a portion of various fibroinflammatory conditions of unknown cause encountered in the chest, including inflammatory pseudotumours, idiopathic interstitial pneumonias, fibrosing mediastinitis, inflammatory pleural lesions and, occasionally, airway disease.Some aspects of pulmonary manifestations attributed to ISD remain controversial and additional studies are needed to clarify the relationship along with the increasing relevance of this disorder to pulmonary medicine.

Background: Limited data exist regarding the population-based epidemiology of idiopathic pulmonary fi brosis (IPF). The objective of the study was to describe the trends in the incidence, prevalence, and clinical course of IPF in the community. Methods:We conducted a population-based study of adult patients with IPF in Olmsted County, Minnesota, from 1997 to 2005. Two methods were used to identify IPF cases, as defi ned by the 2002 American Thoracic Society/European Respiratory Society consensus statement: (1) usual interstitial pneumonia (UIP) on a surgical lung biopsy specimen or a defi nite UIP pattern on a high-resolution CT image (narrow criteria) and (2) UIP on a surgical lung biopsy specimen or a defi nite or possible UIP pattern on CT image (broad criteria). Results: Of 596 patients screened for the possibility of pulmonary disease or pulmonary fi brosis over 9 years of follow-up, 47 cases had IPF. Of these, 24 met the narrow criteria. The age-and sex-adjusted incidence was 8.8/100,000 and 17.4/100,000 person-years, for narrow and broad criteria, respectively. The age-adjusted incidence was higher in men than in women, and among patients aged 70-79 years. During the study period, the incidence of IPF decreased ( P , .001). On December 31, 2005, the age-and sex-adjusted prevalence was 27.9/100,000 and 63/100,000 persons by narrow and broad criteria, respectively. Thirty-seven patients experienced a total of 53 respiratory exacerbations (26 IPF related, 27 non-IPF related), and 34 (72%) patients died. The primary cause of death was IPF related in 16 (47%) patients. Median survival for narrow-criteria and broad-criteria incidence cases was 3.5 and 4.4 years, respectively. Conclusions: The incidence of IPF in Olmsted County decreased over the study period. Nonprimary IPF respiratory exacerbations are as frequent as primary IPF respiratory exacerbations and an important cause of death.CHEST 2010; 137( 1 ):129-137Abbreviations: ATS/ERS 5 American Thoracic Society and European Respiratory Society; HRCT 5 high-resolution computed tomography; IPF 5 idiopathic pulmonary fi brosis; REP 5 Rochester Epidemiology Project; UIP 5 usual interstitial pneumonia