Telomere Shortening, Regenerative Capacity, and Cardiovascular Outcomes.

RATIONALE: Leukocyte telomere length (LTL) is a biological marker of aging, and shorter LTL is associated with adverse cardiovascular outcomes. Reduced regenerative capacity has been proposed as a mechanism. Bone marrow-derived circulating progenitor cells are involved in tissue repair and regeneration. OBJECTIVE: Main objective of this study was to examine the relationship between LTL and progenitor cells and their impact on adverse cardiovascular outcomes. METHODS AND RESULTS: We measured LTL by quantitative polymerase chain reaction in 566 outpatients (age: 63±9 years; 76% men) with coronary artery disease. Circulating progenitor cells were enumerated by flow cytometry. After adjustment for age, sex, race, body mass index, smoking status, and previous myocardial infarction, a shorter LTL was associated with a lower CD34+ cell count: for each 10% shorter LTL, CD34+ levels were 5.2% lower (P<0.001). After adjustment for the aforementioned factors, both short LTL (

Diagnostic Utility of PD-L1 Expression in Lung Adenocarcinoma: Immunohistochemistry and RNA In Situ Hybridization.

BACKGROUND: Programmed death receptor and programmed death ligand (PD-L1) are immunoregulatory proteins. Nonsmall cell lung cancer bypasses the immune system through the induction of protumorigenic immunosuppressive changes. The better understanding of immunology and antitumor immune responses has brought the promising development of novel immunotherapy agents like programmed death receptor checkpoint inhibitors. The aim of this study was to investigate the expression of PD-L1 in lung adenocarcinoma (ADC), comparing 2 different technologies: immunohistochemistry (IHC) by 2 methods versus RNA in situ hybridization (RISH). METHODOLOGY: In total, 20 cases of ADC of the lung and 4 samples of metastatic colon ADC were selected. Evaluation of PD-L1 expression was performed by IHC and RISH. RISH was performed using RNAscope. Both methods were scored in tumor cells and quantified using combined intensity and proportion scores. RESULTS: Eight of 20 (40%) lung ADC and 2 of 4 (50%) colon ADC were positive for PD-L1 with Cell Signaling IHC, and 65% lung ADC were positive by Dako IHC (13/20). All 4 cases of colon ADC were negative. When evaluated by RISH, 12 lung ADC (60%) and 1 colon ADC (25%) were PD-L1 positive. CONCLUSIONS: RNAscope probes provide sensitive and specific detection of PD-L1 in lung ADC. Both IHC methods (Cell Signaling and Dako) show PD-L1 expression, with the Dako method more sensitive (40% vs. 65%). This study illustrates the utility of RISH and Cell Signaling IHC as complementary diagnostic tests, and Food and Drug Administration approved Dako IHC as a companion diagnostic test.

Double staining: diagnostic utility in non-small cell lung carcinoma in the era of tissue conservation.

INTRODUCTION: In an era of precision medicine distinguishing pulmonary squamous cell carcinoma (SQCC) from adenocarcinoma (ADC) is vital for treatment. Immunohistochemical (IHC) staining for p40, p63 and Cytokeratin 5 (CK5) are useful for SQCC, while TTF-1 and Napsin-A can be used for confirming ADC. Fine needle aspiration (FNA) cell blocks (CB) have limited tissue, hence, double IHC staining is helpful for tissue conservation for molecular analysis. MATERIALS AND METHODS: Thirty six confirmed lung SQCC and 45 ADC CB were selected for IHC. Double staining was performed with p40/CK5 and p63/CK5 on all SQCC, and with TTF-1/Napsin-A on all ADC. Results were positive if at least 5% of malignant cells were immunoreactive for the antigen. RESULTS: P40/CK5 had (92%) sensitivity, (100%) specificity, (100%) positive predictive value (PPV), (91%) negative predictive value (NPV) and an overall diagnostic accuracy of (96%). By contrast, P63/CK5 double stains showed (92%) sensitivity, (80%) specificity, (85%) PPV, (89%) NPV and (86%) overall diagnostic accuracy, respectively. TTF-1/Napsin A staining for ADC showed a sensitivity of 80%, specificity of 96%, PPV of 97%, NPV of 71% and accuracy of 85%. CONCLUSION: P40/CK5 double stain has higher specificity, PPV, NPV, and overall accuracy than P63/CK5 double stain in the diagnosis of lung SQCC. TTF-1/Napsin-A double staining is a valuable marker with high specificity, PPV, and diagnostic accuracy in diagnosing lung ADC. The usage of P40/CK5 and TTF-1/Napsin-A as a panel can be recommended for characterizing non-small cell carcinoma (NSCC) of the lung and for conserving tissue for molecular testing.

Parafibromin, APC, and MIB-1 Are Useful Markers for Distinguishing Parathyroid Carcinomas From Adenomas.

BACKGROUND: Differentiation of parathyroid carcinoma (PC) from parathyroid adenoma (PA) relies solely on the pathologic determination of invasion of surrounding structures and/or distant metastasis. Parathyroid lesions with atypical histologic features with no demonstration of invasion or metastasis present a diagnostic dilemma. Different authors report a parafibromin and adenomatous polyposis coli (APC) loss or reduction in PC cases. High proliferative activity of MIB-1 and increased galectin 3 expression are reported in PC. There is no clear cutoff for the sensitivity, specificity, or predictive value for all these markers. METHODS: The immunohistochemical expression of parafibromin, APC, MIB-1, and galectin 3 was studied in 73 adenomas, 21 PCs, and 3 atypical adenomas. The presence or absence of each marker was identified through the use of a comprehensive scoring system based on multiplying the percentage of tumor cells stained (0 to 100) and the staining intensity (0 to 3) on each biopsy. The highest score that any slide could reach was 300. A cutoff of >100 was used to consider the specimen positive for parafibromin, APC, or galectin 3 staining. MIB-1 proliferation indices were calculated using image cytometry; proliferation indices >5% were considered positive. RESULTS: We identified parafibromin loss in 7/21 (33%) carcinomas and 1/73 (1%) adenomas. Loss of APC was seen in 20/21 (95%) carcinomas and 38/73 (52%) adenomas. MIB-1 indices were elevated in 18/21 (86%) carcinomas. MIB-1 indices were <5% in all (100%) adenomas. MIB-1 indices were elevated in 2/3 (67%) atypical adenomas. CONCLUSIONS: Our study presents a clear cutoff to determine the practicality of using parafibromin, APC, and MIB-1 as immunohistochemical markers to differentiate between PCs and PAs. Loss of parafibromin and a high MIB-1 index are both independently sensitive and specific markers for the diagnosis of PC. Loss of APC was only specific for PC. This panel of markers provides a novel, useful approach in the diagnosis and differentiation of PCs from PAs.