Correspondence n engl j med 375;11 nejm.org September 15, 2016 excluded for right-sided pulmonary-vein diameters greater than 26 mm. In the trial, 98.9% of all pulmonary veins were isolated at the index procedure in the cryoballoon group, as compared with 97.9% in the radiofrequency group. In the cryoballoon group, 100% of the left common pulmonary veins (28 of 28) and 92% of the right middle pulmonary veins (12 of 13) were isolated at the index procedure. In the radiofrequency group, 77% of the left common pulmonary veins (30 of 39) and 48% of the right middle pulmonary veins (11 of 23) were isolated at the index ablation.Currently, prescreening of pulmonary-vein anatomical features is not required. More important, the cryoballoon group has shown significantly fewer reinterventions and rehospitalizations than the radiofrequency group, 3 and these patient-relevant disease-burden characteristics should be considered when making the decision about what type of catheter ablation should be performed.

Immunization with CL-14-trypomastigotes generates efficient humoral and cellular responses against infective challenge. Herein, we investigated the relevance of these mechanisms in vivo. Immunization with live CL-14-trypomastigotes protected only part of beta2m(-/-) mice but efficiently protected perforin-knockout mice. Fixed CL-14-trypomastigotes could successfully immunize BALB/c, though live trypomastigotes lowered the requirements for doses and time intervals. Post-immune depletion of CD4 or CD8 subsets did not affect protection conferred by immunization, but switched the production of anti-Trypanosoma cruzi antibodies to IgG2a. Sublethal irradiation partially broke the resistance of immune mice, leading to development of late parasitemia. Passive serum transfer from immune mice conferred protection to nai;ve mice. Our results indicate that presentation of cytosolic antigens by MHC class I molecules is involved in the generation of immunity and suggest that the humoral response contributes to a great extent to keep CL-14-immunized mice protected against infective challenge.