Hi Angela,

My colleagues and I at UCSF published a letter to Clinical Chemistry on this topic some time ago:

Canfell, P.C., Binder, S.R. and Khayam-Bashi, H. “Pediatric Reference Intervals for Normetanephrine/Metanephrine (Letter).” Clinical Chemistry 1986; 32:222-223.

As you appreciate, this kind of study is very hard to perform, which is why there have been few efforts to repeat it. The method used was GC/MS, which in my hands agreed with HPLC within 15-20%, so this offers some guideline as to what you might expect. The advantage of metanephrines for spot urine is that output and stability do not depend on pH, so I believe you are making the right move.

Regards,

Steven R. Binder
Director, Technology Development
Clinical Diagnostics Group
Bio-Rad Laboratories
4000 Alfred Nobel Drive
Hercules CA 94547
Phone : 510-741-4603
e-mail: [log in to unmask]

From: Kremmyda Angela <[log in to unmask]>
To: <[log in to unmask]>
Date: 03/28/2011 08:32 AM
Subject: Urine mets to creatinine ratio
Sent by: Clinical biochemistry discussion list <[log in to unmask]>

Dear all,

We are about to move from measuring urine catecholamines to (urine) metanephrines for screening for phaeo. Currently we ask for spot urine(s) and use the ratio to creatinine and we’d like to keep it like that for the metanephrines (instead of having 24 h urine collections). Our problem is there is no reference range provided by the manufacturer for the ratio and we’re finding it very difficult to find any other data. Are there any users out there that use the ratio to creatinine and would be willing to share their normal range? Our method is HPLC.
Any help would be very welcome (we are getting a bit desperate…).

Thanks in anticipation

Angela

Angela Kremmyda
Senior Biochemist

Dept of Clinical Biochemistry
Royal Shrewsbury Hospital
Mytton Oak Road
Shrewsbury
SY3 8XQ

Tel: 01743 261158
Fax: 01743 261159

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