Transbronchial cryobiopsy alone versus combined with traditional forceps biopsy for acute cellular rejection in lung transplant recipients. A diagnostic randomized trial.

BACKGROUND

Transbronchial lung biopsy is routinely performed to identify acute cellular rejection (ACR) in lung transplant recipients (LTRs). This trial evaluates the clinical value of forceps and cryobiopsies versus cryobiopsies as a standalone diagnostic tool.

METHODS

In this randomized trial, LTRs were randomly assigned to receive either 2 cryobiopsies (cryobiopsy group) or a combination of 5 forceps- and 2 cryobiopsies (combined group). The primary outcome was the diagnostic yield to detect ACR; the secondary outcome was the incidence of ACR. We conducted a paired, intraindividual comparison in the combined group alongside interindividual comparisons.

RESULTS

A total of 80 LTRs were randomly assigned to the cryobiopsy group ( = 40) or the combined group ( = 40) with 90 and 87 procedures performed, respectively. The diagnostic yield for ACR in the cryobiopsy group was similar to the combined group (95.6% vs 97.7%,  = 0.430). The sole use of cryobiopsies did not lead to a lower ACR incidence compared to the combined group (10% vs 17.2%, risk ratio 2.21 [95% confidence interval (CI) 0.67-7.29];  = 0.190). Adverse events did not differ between the 2 groups (60.9% vs 57.5%,  = 0.655). The pneumothorax rate was overall 1.7%. There were no deaths or occurrences of severe bleeding.

CONCLUSIONS

Cryobiopsies did not detect lower ACR than the combined group and can be used as primary and standalone diagnostic tools for histologic assessment of ACR without requiring forceps biopsies.