Laboratory biosafety measures in receiving, preparation and processing of pathology specimens in suspected and positive coronavirus infection

COVID-19, caused by SARS-CoV-2 virus which is declared as a pandemic by the WHO on March 2020 has made a huge difference in the practice and daily activities of the laboratory services. There are high chances of receiving potentially infectious samples to the laboratory for various tests. Authors propose a few biosafety measures in the preparation and processing of various pathology specimens received to the lab during this pandemic time in correlation with guidelines given by WHO. These safety measures aim at protecting and safe guarding the laboratory staff, trainees, and pathologists by minimizing the exposure to COVID-19.

Langerhans cell histiocytosis of liver

Langerhans cell histiocytosis (LCH) is a rare disorder of unknown etiology caused by proliferation of Langerhans cells. It can involve single organ system to multi organ systems and clinical presentation is variable depending on the organ involved and have different prognosis. LCH is common in children when compared to adults. Hepatic involvement in adults is relatively rare. Liver involvement has considerable impact on survival rates. Histopathology and immunohistochemistry provide the definitive diagnosis. Authors report a case of Langerhans cell histiocytosis in a young adult with hepatic involvement.

Vascular anatomy of strictured small bowel.

Aim: To investigate the role of ischemia in the pathogenesis of small bowel strictures. Methods: Vascular anatomy of 39 small bowel strictures was studied using modified Spalteholtz method. Ten normal small bowel segments were studied as controls. Results: 71.8% of small bowel strictures showed block in the mesenteric vessels (p=0.008). Subset analysis of tuberculous strictures showed block in the mesenteric vessels in 70.8% of strictures (p=0.0098). Conclusions: Ischemia plays a significant role in the pathogenesis of small bowel strictures. Mesenteric vasculopathy has a significant association with tuberculous strictures of the intestine.

Absence of Mycobacterium avium ss paratuberculosis-specific IS900 sequence in intestinal biopsy tissues of Indian patients with Crohn’s disease.

Background and Objective The role of Mycobacterium avium ss paratuberculosis (MAP) in the etiopathology of Crohn’s disease (CD) remains controversial, because of conflicting reports demonstrating the presence of MAP-specific insertion sequence from intestinal biopsy tissues of patients clinically diagnosed for the disease. The present study was carried out to investigate the presence of MAP DNA in the intestinal tissues of CD patients to ascertain the relevance of MAP in Indian patients with CD. Methods Patients diagnosed as CD at our institute were recruited. Healthy individuals without inflammatory bowel disease served as controls. Mucosal biopsy specimens were collected from ileum and colon in duplicates and subjected to histopathological examination and polymerase chain reaction (PCR) amplification. Total DNA (81 CD patients, 85 healthy individuals) and total RNA (12 CD patients, 12 healthy individuals) isolated from tissue specimens was used for amplification of MAP-specific IS900 by nested PCR. Results MAP-specific IS900 DNA and RNA could not be detected by nested PCR in the intestinal tissues of any patient with CD. Conclusion Our results do not support the etiological role of MAP in the pathogenesis of CD in Indian patients.