Trauma and inflammation modulate lymphocyte localization in vivo: quantitation of tissue entry and retention using indium-111-labeled lymphocytes

Abstract

Objective: Determine the in vivo localization pattern of indium-111-labeled lymphocytes after a standardized extremity injury or standardized laparotomy and after sterile inflammation of the central nervous system.

Design: Prospective animal study with concurrent controls.

Setting: Animal research laboratory.

Subjects: Male Lewis rats weighing 150-175 g.

Interventions: Indium-111-labeled splenic lymphocytes were injected into animals after a standardized hind limb trauma or laparotomy and after induction of sterile central nervous system inflammation.

Measurements and main results: Lymphoid and non-lymphoid organs were removed at fixed intervals after lymphocyte injection and the proportion of injected lymphocytes/gram of tissue was determined using a quantitative radionuclide calculation. Results from treated animals were compared with results from untreated control animals. Muscle injury caused early localization of lymphocytes to injured hind limbs, liver, and spleen compared with controls, whereas laparotomy decreased lymphocyte localization in the thymus and colon. Encephalitis increased localization to the central nervous system with no effect on other tissues.

Conclusions: These results identify a sensitive method to track in vivo leukocyte localization and specifically demonstrate that lymphocyte localization is altered in both traumatic and nontraumatic models of inflammation.