Which two markers were evaluated for mucosal expression in GI biopsies from cats with small cell GI lymphoma versus inflammatory bowel disease?

• A. TNF-α and IL-6
• B. NF-κB and infiltrating CD11b+ immune cells
• C. NF-κB and CD3+ T cells
• D. TLR4 and CD21

Answer: (B)

The two markers focus on different aspects of the mucosal immune environment that help distinguish inflammatory vs neoplastic processes in the feline GI tract. NF-κB is a key transcription factor that drives a wide range of inflammatory genes and is activated in many inflammatory conditions as well as in cancer-associated inflammation. Infiltrating CD11b+ immune cells identify innate myeloid cells, such as macrophages and neutrophils, whose presence reflects the degree and pattern of mucosal inflammation and cellular recruitment.

In cats with small cell GI lymphoma versus inflammatory bowel disease, evaluating both NF-κB activity and CD11b+ cell infiltration provides a complementary view: NF-κB indicates active inflammatory signaling within the mucosa, while CD11b+ infiltration reflects the extent of innate immune cell recruitment. The combination can reveal a mucosal signature more consistent with neoplastic lymphoid infiltration in lymphoma versus the prominent myeloid-driven inflammation seen in IBD, making these two markers the most informative pair for comparing these two conditions.