Table 1.

Comparing the levels of complement C4d, factor D and ficolin B by Immunohistochemical staining (IHC) from the ankles of WT, FCN B^−/− and MASP-2/sMAp^−/− mice with CAIA

Complement	1 Mice		1 Mice
	WT	FCN B−/−	WT	MASP-2/sMAp−/−
2 C4d	Low level	Low level	Low level	Negative
3 fD	Very high level	Low level	Very high level	Medium level
4 FCN B	Very high level	Negative	Very High level	Very high level

¹Ankle joints formalin fixed, paraffin-embedded sections from the C57BL WT (littermates) and FCN B^−/− and WT (littermates) and MASP-2/sMAp^−/− mice with collagen antibody induced arthritis (CAIA) were used for the IHC detecting the presence of membrane bound/and or in the cytoplasm of C4d deposition, fD deposition and FCN B deposition. CAIA was induced in these mice as mentioned in the Materials and Methods.

²C4d classical pathway C4d component.

³fD = factor D alternative pathway component.

⁴FCN B = ficolin B lectin pathway component. An ordinal scoring was method used i.e. Negative = no staining of any cell was seen compared with the positive control at a specific antibody dilution, low level = few cells positive (less than 15) in the synovium, cartilage and adipose cells were positive, medium = some cells positive (from 15–30) in the synovium, cartilage and adipose cells were positive, and very high level = many cells positive (more than 30) in the synovium, on the cartilage surface and adipose cells were clearly visible. An antigen retrieval method was consistently used to detect all three antigens on paraffin-embedded tissue sections. All slides were scored blindly by a trained IHC personal. Specific dilutions used of each primary antibody has been mentioned in the Materials and Methods.