Tamm-Horsfall protein in lymph nodes

Area of Science:

• Nephrology
• Immunology
• Pathology

Background:

• Tamm-Horsfall protein (THP) is primarily found in renal tubules.
• The presence and role of THP outside the renal tubules, particularly in relation to renal tumors, are not well understood.

Purpose of the Study:

• To investigate the presence and origin of amorphous material found in lymph nodes associated with renal tumors.
• To determine if this material is Tamm-Horsfall protein and understand its pathway into lymph nodes.

Main Methods:

• Histochemical and immunohistochemical analysis of lymph node biopsies and resected kidneys.
• Microscopic examination of renal tubules, casts, and lymphatics.

Main Results:

• Amorphous, waxy material identical to THP was identified in the peripheral sinuses of lymph nodes adjacent to renal tumors.
• THP was also detected within renal tubules, tubular casts, and intrarenal lymphatics in the affected kidneys.
• THP was confined to the compressed residual kidney tissue and absent in the tumors themselves.

Conclusions:

• THP can escape from renal tubules into the interstitium, potentially causing inflammation.
• THP gains access to intrarenal lymphatics and regional lymph nodes, which may be relevant for antibody responses in patients with renal tumors.