Specimen Collection Recommendations for Pathologic Evaluation of Hepatitis
Pathogens that cause hepatitis may be distributed focally or sparsely in the liver, despite extensive inflammatory infiltrates in the involved tissues. Because hepatitis can occur in the context of systemic diseases or as a manifestation of a primary infection involving another organ systems, collecting multiple representative portions of hepatic tissue, as well as tissue samples from any other organ system with inflammatory cell infiltrates or other findings suggestive of infection, ensures the best chance of detecting the causative agent.
Performance of specific immunohistochemical, molecular, or other assays will be determined using clinical and epidemiologic information provided by the submitter and the histopathologic features identified in the submitted tissue specimens.
Electron microscopy (EM) may provide important diagnostic information and in this context, samples preserved for EM may also be submitted for potential evaluation. Please refer to CDC’s Infectious Diseases Laboratory Test Directory, Test Order Code entry for Transmission Electron Microscopy (EM) Evaluation for Possible Infectious Etiologies (CDC-10559) for detailed information on acceptable specimens and specimen submission instructions.
Collection of Tissue Specimens
The preferred specimens include a minimum of 2 formalin-fixed paraffin-embedded (FFPE) blocks of involved hepatic tissue or, for autopsies only, representative formalin-fixed wet tissues.
Specific guidelines for these samples include:
- Multiple fragments of liver tissue involved by inflammatory infiltrates
If hepatitis is identified in the context of a fatal systemic illness and an autopsy is performed, representative tissues should be included from any other organ showing significant microscopic pathology.
