Professor John Soothill

Great Ormond Street immunologist specialising in allergies

Falstaffian in stature, enthusiastically explaining his latest idea before another came bubbling up in its place, John Soothill lived for his investigative medicine and encouraged countless others to share his energetic pursuit of answers to nature's many questions.

John Farrar Soothill, immunologist and paediatrician: born London 20 August 1925; Lecturer in Experimental Pathology, Birmingham University 1956-65; Hugh Greenwood Professor of Immunology, Institute of Child Health 1965-85 (Emeritus); married 1951 Brenda Thornton (three sons, one daughter); died Axminster, Devon 23 September 2004.

Falstaffian in stature, enthusiastically explaining his latest idea before another came bubbling up in its place, John Soothill lived for his investigative medicine and encouraged countless others to share his energetic pursuit of answers to nature's many questions.

In his long career as a leading paediatrician, working notably in the field of immunology and child allergies, he taught three future vice-chancellors and over 30 professors. He never thought of guarding research as his own; rather it was his only instinct to share and discuss until the way forward became clear.

John Soothill was born in 1925 in Blackheath, south-east London, but brought up in Norfolk, his father being Medical Officer of Health in Norwich. Educated at the Leys School in Cambridge, he went up to Christ's College, Cambridge, to read Medicine, and thence to Guy's Hospital. At school he had his own boat on the Broads and when the Leys was evacuated during the Second World War to Pitlochry in Perthshire took up mountaineering.

As he completed his houseman's stint at Guy's he met his future wife, Brenda, who was finishing her own studies at the Royal Academy of Music before becoming a professional violinist. Qualifying in 1946, he did his two years' military service which took him to Germany. On his return he jumped at the opportunity of a year in Chicago on a Fulbright Scholaship, where his work concentrated on renal research and the newly acquired technique of renal biopsy that was to lead to renal transplants.

Back in England, he took up a position at Birmingham University in the Experimental Pathology Department. He and his wife settled into an idyllic lock-keeper's house, somewhat dilapidated to begin with, but there was nothing John could not fix given his embrace of DIY. Home-making was followed by rearing their family, a daughter first followed by three sons - all of whom have made distinguished careers in science, Mary as a statistician based in Oxford working on childhood cancer epidemiology, James as a consultant microbiologist at Great Ormond Street Hospital for Sick Children, Peter as Professor of Maternal and Foetal Medicine at Bristol University, Charles as Vice-President of Alstom Power Technology Centre in Leicester.

John Soothill spent nine years at Birmingham, before he was head-hunted by Great Ormond Street Hospital. In 1965, he became the first Hugh Greenwood Professor of Immunology, at the Institute of Child Health. To begin with his department numbered but two, himself and the experimental scientist brought with him from Birmingham.

From the outset, Soothill insisted that, although the clinical experience at Great Ormond Street was almost exclusively caring for very sick children, ordinary children and their common diseases should not be neglected. Thus he would lead his department into the root causes of asthma, the allergy components of eczema, the origins of hay fever. While on death-threatening conditions such as leukaemia he was no less intent, he was able to demonstrate the vital role played by the innate immune system (that which underpins the acquired system).

Allergies were first identified by the Austrian paediatrician Clemens von Pirquet in 1906. He and other pioneers developed the theory that the body was reacting to a foreign protein. It was John Soothill who refined this line of conjecture by showing that severe cases of allergy arise due to exposure of the immature immune system in a baby during the first six months.

In order to identify precisely those food or foods which trigger reactions, he instigated "dietary avoidance". A hit list was compiled of possible allergic sources in a list of foods: the child would then be refused all of them and, once his or her condition was stabilised, the foods would be reintroduced one by one until the identity of the causal food was established.

Another pioneer field which held Soothill's attention was the "boy in the bubble" syndrome, which he was the first to name formally. The general cause of immunodeficiency had been determined in 1952, and the syndrome had been personified in the affecting case of David Vetter, the Texas boy born in 1971 who lived his 12-year life in a protective bubble. But it wasn't until 1975, at a World Health Organization conference in Geneva, that Soothill named it severe combined immunodeficiency syndrome.

"Scid" can often cause death in a child before the age of two if it goes undetected. Soothill identified two distinct groups and demonstrated the syndrome's genetic origin. As to treatment, recent advances in bone-marrow transplant offer patients a better chance of recovery.

A constant stream of student doctors passed through Soothill's hands, many of them from overseas. He might seem forbidding at first encounter, but they warmed to his enthusiastic energy and the selfless way in which he allowed them space to pursue their own work. Always on the move, announcing his presence by his deep baritone boom, he would never pass one by in the corridor without a detailed update of work in progress, the latest development, a new line of pursuit. They would be asked back to parties at his home in Hampstead Garden Suburb that were famous for their generosity, the music and the opportunity to meet leading medical personalities from all over the world.

With A.R. Hayward and C.B.S. Wood, Soothill was the editor of the textbook Paediatric Immunology (1983).

John Soothill retired early at the age of 60, declaring that the most fertile minds were young minds and he would make way for the next generation, handing over his work for them to carry forward. He continued his clinical work with children for another five years. But he and his wife soon became busier than ever in retirement, sailing, swimming in the sea and above all making music together.

John Skinner