Langerhans Cell Histiocytosis or Acute Cellular Rejection?

Area of Science:

• Immunopathology
• Transplant Medicine
• Oncology

Background:

• Langerhans cell histiocytosis (LCH) is a rare disorder involving dendritic cell infiltration, potentially causing organ dysfunction.
• A liver transplant recipient developed cholangiopathy, raising the question of whether observed Langerhans cells (LC) indicated acute cellular rejection (ACR) or recurrent LCH.

Purpose of the Study:

• To differentiate between acute cellular rejection (ACR) and recurrent Langerhans cell histiocytosis (LCH) in liver allografts.
• To evaluate the specificity of CD1a and CD207 immunostaining for diagnosing recurrent LCH in post-transplant cholangiopathy.

Main Methods:

• Immunohistochemical analysis using CD1a and CD207 antibodies was performed on a liver transplant patient with suspected recurrent LCH.
• A comparative analysis was conducted on 14 additional patient samples with acute cellular rejection (ACR).

Main Results:

• Among 15 samples, 80% showed positive staining for CD1a and/or CD207.
• Four samples (26.7%), including the index case, exhibited co-expression of both markers in bile duct epithelium and surrounding tissue.
• Six samples (40%) showed staining for only one marker.

Conclusions:

• Immunostaining for CD1a and CD207 identifies Langerhans cells (LC) in damaged bile ducts, even in the absence of suspected LCH.
• The co-expression of CD1a and CD207 is not specific to recurrent LCH in liver allografts.
• The presence of CD1a+/CD207+ cells alone is insufficient to confirm recurrent LCH in the context of post-transplant liver disease.