Measurement of GFR by Cr51-EDTA clearance

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Measurement of GFR by Cr51-EDTA clearance

Photo Cyril Chantler

Professor Sir Cyril Chantler, was one of the first paediatric nephrologists in the UK. From 1973 he directed  the world famous paediatric nephrology unit at Guy’s Hospital. He later became a major figure in national clinical and academic leadership.

But in the late 1960s when he was plain Cyril Chantler, a young paediatric trainee, he completed and published research which has had a seminal influence on clinical nephrology. He developed and validated the measurement of plasma clearance of intravenously infused Cr51-EDTA as a measurement of GFR. It was intentionally designed for use in children in whom timed urine collections to allow calculation of creatinine clearance as a surrogate for GFR were impossibly unreliable. But it became a routine part of clinical care in adults and children whenever accurate GFR measurement was required.

The story behind this important development is best told by Cyril Chantler himself in words taken from an interview he gave for Kidney Research UK in 2018. It is a story which reflects the serendipity which often underlies research progress, and the relaxed approach to ‘health and safety’ often taken in clinical research in that era. And we hear about Norman Veall (not a nephrologist), Cyril’s supervisor who was a remarkable and colourful figure.

 

“There were almost no paediatric nephrologists in the UK in the 1960s. If I wanted to be a  paediatric nephrologist, I thought there was one particular problem which we had to deal with. I remember discussing this with Martin Barratt[1], who was an important friend of mine for many years.  It seemed to me that you couldn’t be the specialist of an organ whose function you couldn’t measure. Most kidney function tests depended on timed urine samples, and the one thing you cannot get from babies and young children is timed urine samples. So we needed to measure glomerular filtration rate, and we needed another way of doing it. 

              I had to pass the adult Membership (MRCP) and I trained as an adult doctor for some years before went into paediatrics. When I was in the middle of working for Membership, I got a job for nine months, working for  Norman Veall, who was head of the MRC medical isotopes unit.  I did an MD project measuring glomerular filtration rate by injecting radioactive chromium EDTA and measuring its decay from the blood.

Norman had read in ‘Science’ the use of chromium51-EDTA  as a tumour marker in sheep., and he thought it may be excreted by the kidney. And it was then I went to work for him. We got very highly radioactive chromium51 to chelate to EDTA, by putting it into little bottles and boiling it in a domestic pressure cooker on a Bunsen burner. It turns a nice violet colour when it is chelated. My job was then to run it through Sephadex columns to make sure there was no free radioactivity, and measure its protein binding, which I did. And then one day he said, ‘Well, that seems about right’, and drew up 10 cc’s, and said ‘would I inject it into his arm’. I said ‘Well, shouldn’t you try it on say a dog first, and he said, ‘ thought you were interested measuring kidney function in children’. So I injected it into him and took blood samples and he injected into me the next day. And I did that about nine more times. So we worked out how to use it, and it proved to be very successful[2]. I can remember him pipetting this highly radioactive chromium51 in the laboratory, while smoking a cigarette in a cigarette holder. And I said to him ‘Norman, aren’t there rules about this sort of thing’. And he said, ‘Yes Cyril, there are – and the rules are written by people like me, for people like you!’

The MRC then  agreed to fund me again, so I went to work in the Institute of Child Health, to apply Cr-51EDTA clearance to children with a variety of different renal diseases.

Cr-51EDTA clearance gave us accurate measurement of GFR but could not be an every day clinical test. And Martin (Barratt), I remember, in a pub near Great Ormond Street[3]  , working out on the back of a beer mat, the relationship between body surface area and muscle mass, which is the key to understanding how you can use plasma creatinine as a surrogate  for glomerular filtration rate[4]. ‘

 

Norman Veall

“Norman Veall was the father of nuclear medicine in this country, ‘Veall & Vetter’, was at that time the bible of nuclear medicine.  He had an unusual career path! He had left school at 16 and joined the Air Ministry Meteorological Office. He then went as a technician to the Cavendish Laboratory in Cambridge Rutherford laboratory. At the outbreak of the Second World War he was sent as a technician to Canada to work on the atom project, during his time there he took an external BSc degree at the University of London in physics. His actual exam script was convoyed to London, because there were no photocopiers – imagine if the convoy had been torpedoed, he’d have had to sit it again! Anyhow, the only degree he ever had was a BSc in physics. After the Second World War, he came back to the UK and was working at Harwell when Chapman Pincher wrote his book on the atom spies. Norman had a few pages all to himself in Pincher’s book because when he was interviewed, he was asked ‘Did you give any secrets to the enemy?’ And he said ‘No, he didn’t because he hadn’t known any. But that, if he had, he would have given them to the enemy because he thought  information about  the atom bomb was too dangerous not to be shared.’ Well, that might have been an honest answer, but it wasn’t quite the answer wanted by the powers that be!  So he left Harwell and went to the Hammersmith Hospital, and then to Guy’s, where I did my project with him.’ 

 

 

 

 

[1] Martin Barratt (1936-2014), professor of paediatric nephrology at Great Ormond Street Hospital.

[2] Glomerular filtration rate measurement in man by the single injection methods using 51Cr-EDTA.Chantler C, Garnett ES, Parsons V, Veall N. Clin Sci. 1969 Aug;37(1):169-80. Estimation of glomerular filtration rate from plasma clearance of 51-chromium edetic acid. Chantler C, Barratt TM. Arch Dis Child. 1972 Aug;47(254):613-7

[3] Very probably the Lamb on Conduit Street, the nearest pub to Great Ormond Street  Hospital and the Institute of Child Health

[4] Estimation of glomerular filtration rate from plasma creatinine concentration in children.

Counahan R, Chantler C, Ghazali S, Kirkwood B, Rose F, Barratt TM. Arch Dis Child. 1976 Nov;51(11):875-8

 

Last Updated on April 5, 2023 by neilturn