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Complement and cytokine response in acute T hrombotic T hrombocytopenic P urpura

2013; Wiley; Volume: 164; Issue: 6 Linguagem: Inglês

10.1111/bjh.12707

1365-2141

John‐Paul Westwood, Kathryn Langley, Edward Heelas, Samuel J. Machin, Marie Scully,

Blood groups and transfusion

Summary Complement dysregulation is key in the pathogenesis of atypical H aemolytic U raemic S yndrome (a HUS ), but no clear role for complement has been identified in T hrombotic T hrombocytopenic P urpura ( TTP ). We aimed to assess complement activation and cytokine response in acute antibody‐mediated TTP . Complement C 3a and C 5a and cytokines (interleukin ( IL )‐2, IL ‐4, IL ‐6, IL ‐10, tumour necrosis factor, interferon‐γ and IL‐17a) were measured in 20 acute TTP patients and 49 remission cases. Anti‐ ADAMTS 13 immunoglobulin G ( I g G ) subtypes were measured in acute patients in order to study the association with complement activation. In acute TTP , median C 3a and C 5a were significantly elevated compared to remission, C 3a 63·9 ng/ml vs. 38·2 ng/ml ( P < 0·001) and C5a 16·4 ng/ml vs. 9·29 ng/ml ( P < 0·001), respectively. Median IL ‐6 and IL ‐10 levels were significantly higher in the acute vs. remission groups, IL ‐6: 8 pg/ml vs. 2 pg/ml ( P = 0·003), IL‐10: 6 pg/ml vs. 2 pg/ml ( P < 0·001). C3a levels correlated with both anti‐ ADAMTS 13 I g G ( r s = 0·604, P = 0·017) and IL‐10 ( r s = 0·692, P = 0·006). No anti‐ ADAMTS 13 I g G subtype was associated with higher complement activation, but patients with the highest C 3a levels had 3 or 4 I g G subtypes present. These results suggest complement anaphylatoxin levels are higher in acute TTP cases than in remission, and the complement response seen acutely may relate to anti‐ ADAMTS 13 I g G antibody and IL ‐10 levels.