CD40LG and lung disorder: We also compared the new predictive progression model with the 5 independent risk factors (pulmonary disease, age, IgM, CD16 + /CD56 + NK cells and AST), and the C-index for the prediction of progression was 0.5432 ± 0.034, 0.639 ± 0.052, 0.683 ± 0.044, 0.647 ± 0.050 and 0.716 ± 0.036, respectively (see Additional file 7: Table S2).