Jacalin, another marker for histiocytes in paraffin-embedded tissues

Area of Science:

• Biochemistry
• Immunohistochemistry
• Pathology

Background:

• Jacalin is a lectin known to bind D-galactose.
• Histiocytes and macrophages play crucial roles in immune responses and tissue homeostasis.
• Accurate identification of these cells is vital for diagnosing various inflammatory and neoplastic conditions.

Purpose of the Study:

• To evaluate the utility of jacalin as a marker for histiocytes and macrophages in formalin- and alcohol-fixed tissues.
• To determine the binding specificity of jacalin in different reactive and neoplastic cellular contexts.
• To assess the potential of jacalin in differential diagnosis of histiocyte-related disorders.

Main Methods:

• Testing jacalin on 75 samples of formalin- and alcohol-fixed tissues.
• Utilizing immunohistochemistry on paraffin-embedded tissue sections.
• Observing and documenting jacalin binding patterns in various cell types and pathological conditions.

Main Results:

• Consistent cytoplasmic staining of histiocytes was observed in reactive sinus histiocytosis, macrophages in follicular hyperplasia, tuberculosis granulomas, and osteoclast-like giant cells in breast carcinoma.
• No significant jacalin binding was detected in eosinophilic granulomas, giant cell tumors, malignant fibrous histiocytomas, Hodgkin's disease, melanomas, nevi, or signet ring cell carcinomas.
• Jacalin demonstrated specific reactivity with free histiocytes/macrophages but not with fixed histiocytes or associated tumors.

Conclusions:

• Jacalin serves as a reliable marker for free histiocytes and macrophages.
• Jacalin's lack of reactivity with fixed histiocytes and certain tumors aids in differentiating histiocyte-mimicking lesions.
• Jacalin shows promise as a diagnostic tool in histiocyte-related pathology.