A survey of clinical laboratories in the Netherlands regarding pre-analytical conditions of renin measurements to prevent cryoactivation

Abstract

Background

Exposure of plasma to low temperatures induces the conversion of prorenin to renin, causing falsely elevated levels of renin. This also happens at storage temperatures of −20°C. Our survey evaluated the pre-analytical procedures used by clinical laboratories in the Netherlands for renin testing and assessed their awareness of recent studies on cryoactivation and their impact on pre-analytical procedures.

Methods

A nine-question online survey about pre-analytical conditions for renin measurements in clinical laboratories was distributed by the Foundation for Quality Assessment in Medical Laboratory Diagnostics (SKML) to 106 clinical laboratories in the Netherlands participating in the external quality assessment scheme for hormone measurements.

Results

Of the 42 labs that responded, pre-analytical practices varied considerably. Time limits for sample receipt ranged from none (31%, n = 13) to <4 h (57%, n = 24) or >4 h (5%, n = 2). Most laboratories transported and centrifuged samples at room temperature (90% and 93%; n = 38 and 39). Storage conditions differed: 79% (n = 33) stored at −20°C, 17% (n = 7) at −80°C, 2% (n = 1) at −40°C, and 2% (n = 1) at room temperature. Twenty-two respondents (52%) were aware of recent literature, and 8 (36%) had changed or planned to change procedures accordingly. Overall, only eight laboratories (19%) followed all recommended steps to minimize cryoactivation.

Conclusions

This survey shows considerable inconsistency in pre-analytical procedures of renin testing in clinical laboratories in the Netherlands. Despite moderate awareness of recent evidence, implementation of optimal preanalytical procedures remains limited. The survey results show that guidelines and scientific evidence have not been fully implemented, and that awareness of the latest evidence does not directly lead to a change in practice.