Arcane apoptosis in appendicitis: clue to COVID-19 in children or coincidence?

We had observed increased apoptosis in two appendixes in children who developed acute appendicitis after COVID-19 infection. We wondered if this was a chance finding or was causal. To investigate whether increased apoptosis was indicative of COVID-19 infection and if the appendix was involved in COVID-19, we evaluated H&E-stained slides of 12 consecutive cases of acute appendicitis in children (6 with past/current COVID-19, 6 negative on PCR). SARS-CoV-2 immunohistochemistry was performed on sections on the Leica BOND-III platform using Severe Acute Respiratory Syndrome (SARS) nucleocapsid mouse monoclonal antibody at 1:100 dilution (catalogue #MA1-7404; Thermo Fisher Scientific) following antigen retrieval, as previously described.1 To determine apoptosis, we used immunofluorescence-based labelling with rabbit polyclonal caspase-3 (1:500 dilution; ab4051, Abcam UK) and visualised the localised protein using a laser scanning confocal microscope (DMi8, Leica Microsystems, Germany), as described previously.2 Positivity was graded based on intensity and number as...
Source: Journal of Clinical Pathology - Category: Pathology Authors: Tags: COVID-19 PostScript Source Type: research