{Reference Type}: Multicenter Study {Title}: Prognosis and long-term outcomes in type I cryoglobulinemia: A multicenter study of 168 patients. {Author}: Ghembaza A;Boleto G;Bommelaer M;Karras A;Javaugue V;Bridoux F;Alyanakian MA;Molinier Frenkel V;Ghillani-Dalbin P;Musset L;Barete S;Roosweil D;Choquet S;Le Joncour A;Mirouse A;Lipsker D;Faguer S;Vieira M;Cacoub P;Biard L;Saadoun D; ; {Journal}: Am J Hematol {Volume}: 98 {Issue}: 7 {Year}: 2023 07 4 {Factor}: 13.265 {DOI}: 10.1002/ajh.26944 {Abstract}: Type I cryoglobulinemia (CG) accounts for 10%-15% of all cryoglobulinemias and are exclusively seen in clonal proliferative hematologic conditions. In this multicenter nationwide cohort study, we analyzed the prognosis and long-term outcomes of 168 patients with type I CG (93 (55.4%) IgM and 75 [44.6%] IgG). Five- and 10-year event-free survivals (EFS) were 26.5% (95% CI 18.2%-38.4%) and 20.8% (95% CI 13.1%-33.1%), respectively. In multivariable analysis, factors associated with poorer EFS were renal involvement (HR: 2.42, 95% CI 1.41-4.17, p = .001) and IgG type I CG (HR: 1.96, 95% CI 1.13-3.33, p = 0.016), regardless of underlying hematological disorders. IgG type I CG patients had higher cumulative incidence of relapse (94.6% [95% CI 57.8%-99.4%] vs. 56.6% [95% CI 36.6%-72.4%], p = .0002) and death at 10 years (35.8% [19.8%-64.6%] vs. 71.3% [54.0%-94.2%], p = .01) as compared to IgM CG, respectively. Overall, complete response of type I CG at 6 months was 38.7%, with no significant difference between Igs isotypes. In conclusion, renal involvement and IgG CG were identified as independent poor prognostic factors of type I CG.