Pediatric Acute Liver Failure & Aplastic Anemia
Aplastic anemia is most commonly seen with infections such as infectious hepatitis, EBV, CMV, parvovirus B19, and HIV. However, there is a correlation between I-PALF and increased risk of developing aplastic anemia (AA) and early signs of bone marrow dysfunction. There are similarities between AA and I-PALF as they are more immune-driven processes involving CD8+ T-cells and high levels of inflammatory cytokines. AA is a well-described condition that may develop concomitantly with acute hepatitis (hepatitis-associated aplastic anemia (HAAA)) or following liver transplant in patients with fulminant liver failure. The first report of AA after ALF was in 1987 by Stock et al. Further cases have described it primarily in pediatric patients with I-PALF (Itterbeek et al. 2002). Mechanistic studies of HAAA have described immunologic dysregulation as the main pathogenesis: activated CD8+ T cells are cytotoxic to myelpoietic bone marrow cells, T-cell clones are formed early on in acute hepatitis, these clones attack similar target antigens including hepatocytes and myeloid cells(Ikawa et al. 2013).