Complement and cell mediated cytotoxicity by antiendothelial cell antibodies in Takayasu's arteritis.
OBJECTIVE
To study complement and cell mediated cytotoxicity by antiendothelial cell antibodies (AECA) in Takayasu's arteritis (TA).


METHODS
Complement dependent cytotoxicity (CDC) and antibody dependent cellular cytotoxicity (ADCC) of AECA positive/negative TA sera were investigated by colorimetric MTT and 51Cr release assays, respectively, using human umbilical vein endothelial cells (HUVEC) as targets.


RESULTS
Seven of 12 (58%) sera positive for IgG and/or IgM AECA exhibited CDC in comparison to none of the 13 AECA negative sera (p = 0.0052). The median value of CDC of the AECA positive group was 14% (range 13-21%) and that of the AECA negative group was 1% (p = 0.0012). Interleukin 1beta (10 U/ml) treatment of HUVEC resulted in enhancement in CDC of 6 of the 7 AECA positive cytotoxic sera, the median enhancement being 17% (range 7-29%). Tumor necrosis factor-alpha (100 U/ml) treatment of the targets resulted in a median enhancement by 36% (range 25-55%) in the CDC of 3 of these 7 sera. No sera exhibited ADCC at any of the effector:target ratios tested (10:1 to 100:1).


CONCLUSIONS
AECA in TA mediate CDC against endothelial cells and may have a pathogenic role in the perpetuation of vascular damage in this disease.
Tripathy
N K
NK
Department of Immunology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
Upadhyaya
S
S
Sinha
N
N
Nityanand
S
S
D000906:Antibodies / Q000032:analysis*; D000920:Antibody-Dependent Cell Cytotoxicity; D003165:Complement System Proteins / Q000032:analysis*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D013625:Takayasu Arteritis / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D000906:Antibodies; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D003165:Complement System Proteins