Determining PD-L1 expression in head and neck squamous cell carcinoma using immunohistochemistry.

Background: Advanced head and neck squamous cell carcinoma (HNSCC) has limited treatment options. Programmed death-ligand1 (PD-L1) expressed by tumor cells interacts with PD-1 receptor on T lymphocytes leading to immune evasive response and survival advantage. Therapy with immune check-point inhibitors target PD-1/PD-L1 blockade inducing tumor regression. Immunohistochemistry (IHC) for PD-L1 expression enables patient selection for immunotherapy and may be considered a potential predictor of clinical response. Methods: A retrospective analysis of IHC for PD-L1 expression using manual laboratory developed technique (LDT) with antibody clone 22C3 (Dako) in 93 cases of HNSCC. PD-L1 expression was correlated with age, gender, tumor site, grade and stage. Results: PD-L1 IHC was performed in 93 cases and immunopositivity was noted in 59 (63.4%) cases. High expression with combined proportion score (CPS) ≥50 was seen in 15 (16.1%) cases and low expression with CPS ≥1 expression was seen in 44 (47.3%) cases. An almost-perfect interobserver agreement was noted by two pathologists for PD-L1 IHC expression (Cohen's kappa coefficient = 0.910). No statistically significant correlation was noted between PD-L1 score and patient demographics, tumor site, grade or stage. Conclusion: Detection of PD-L1 status by IHC enables identification of HNSCC patients eligible for future targeted immunotherapy.

Interesting post-mortem findings in a H1N1 influenza-positive pneumonia patient.

Reports of histopathological findings in a patient infected with H1N1 influenza virus are limited in the literature, although many deaths have occurred because of this viral infection. In an otherwise healthy individual with no underlying co-morbid conditions, this virus passes off as a very mild disease. However, it can be fatal in the presence of underlying risk factors. Here, we present the autopsy findings of a patient who died of H1N1 infection, but who was apparently healthy with no predisposing ailments. The autopsy revealed chronic kidney disease and caseating granulomatous lymphadenitis in addition to the known classical diffuse alveolar damage picture seen in this condition. These underlying co-morbidities may provide greater insight and a better understanding of this infection.

Interesting post-mortem findings in a H1N1 influenza-positive pneumonia patient

Reports of histopathological findings in a patient infected with H1N1 influenza virus are limited in the literature, although many deaths have occurred because of this viral infection. In an otherwise healthy individual with no underlying co-morbid conditions, this virus passes off as a very mild disease. However, it can be fatal in the presence of underlying risk factors. Here, we present the autopsy findings of a patient who died of H1N1 infection, but who was apparently healthy with no predisposing ailments. The autopsy revealed chronic kidney disease and caseating granulomatous lymphadenitis in addition to the known classical diffuse alveolar damage picture seen in this condition. These underlying co-morbidities may provide greater insight and a better understanding of this infection.