Professor Sir John Dacie

Founding father of haematology in Britain

John Vivian Dacie, haematologist: born London 20 July 1912; pathologist, Emergency Medical Service 1939-42; Senior Lecturer in Clinical Pathology, then Reader in Haematology, Postgraduate Medical School (later Royal Postgraduate Medical School) 1946-56, Professor of Haematology 1957-77 (Emeritus); President, British Society for Haematology 1964; FRS 1967; President, Royal College of Pathologists 1973-75; Chairman, Medical and Scientific Advisory Panel, Leukaemia Research Fund 1975-85; Kt 1976; President, Royal Society of Medicine 1977-78; married 1938 Margaret Thynne (two sons, two daughters, and one son deceased); died London 12 February 2005.

John Dacie was a founding father and for decades the unchallenged leader and teacher of haematology in Britain. He played an important role in the development of academic haematology and established the concept that the specialist haematologist should be proficient in both laboratory investigations and clinical management of patients with blood diseases.

Dacie demonstrated a remarkable ability to solve the most complex problems of diagnosis by critical assessment of the laboratory data and he was able to extract maximum information about a patient's clinical state from the microscopic appearances of a blood film.

The training programme which he directed at the Royal Postgraduate Medical School of London University, based at Hammersmith Hospital, was unrivalled, and greatly influenced the practice of haematology in the UK as well as overseas, attracting the most able young graduates. He instilled in them the need for high standards in research and clinical work and the highest level of technical proficiency in the laboratory.

Dacie was born in Putney, London, in 1912. He went to King's College School in Wimbledon, thence to King's College Hospital Medical School, London, where he graduated in 1935. After a brief period in the wards, he joined the clinical pathology laboratory as a postgraduate student under the nutritionist R.C. McCance. In 1937, as the recipient of an MRC Studentship, he spent six months in (Dame) Janet Vaughan's department at the then Postgraduate Medical School and under her influence he began a study of anaemia, especially the haemolytic anaemias, which would continue throughout his career.

For the second half of his Studentship he went to Manchester Royal Infirmary, to the department of Dr John Wilkinson, where he investigated a patient with a rare chronic haemolytic anaemia descriptively termed paroxysmal nocturnal haemoglobinuria (PNH). He studied the in vitro behaviour of the patient's blood and he developed a specific diagnostic test at the same time as a similar study was being undertaken in Boston by Hale Ham.

During the Second World War, Dacie served in the RAMC, reaching the rank of lieutenant-colonel. On his demobilisation, in 1946, he was appointed as Senior Lecturer in Clinical Pathology in the Postgraduate Medical School (later the Royal Postgraduate Medical School) at Hammersmith Hospital, and in 1957 he was appointed by London University to the first Chair of Haematology to be established in the UK.

Over the following 40 years he investigated many patients with PNH. In 1962 he postulated that it occurred as a result of an attempt at regeneration by a damaged bone marrow, leading to a somatic mutation with production of a new clone of abnormal stem cells with an unusual biological advantage which enables them to crowd out and replace the normal stem cells, and to produce red blood cells with the PNH defect. In recent times there has been increasing evidence to support this theory and there have been important implications in the observation for understanding the biopathology of leukaemia and other disorders.

From careful case studies, morphology and relatively simple laboratory procedures, Dacie contributed to the understanding of other blood diseases, especially various types of haemolytic anaemia. He published and lectured extensively on these topics, continuing his interest in them long after he had formally retired.

During his academic years he published over 170 scientific papers. His major undertaking was Haemolytic Anaemias: the first edition of this unique treatise appeared in 1954, whilst the third edition was published in five volumes, the first in 1985, and the final one was completed in 1998, a magnum opus which is a fitting memorial to his intellect and to the breadth of his scientific and technical knowledge of the subject, and also to his scholarly style of writing, perhaps reminiscent of Anthony Trollope, an author whom he greatly admired.

His expertise was not restricted to haemolytic anaemias, and although he did not personally treat patients with leukaemia, he was a master in diagnosing the type of leukaemia from their morphology. In due course he became Chairman of the Leukaemia Research Fund and helped to direct fundamental studies in this field.

Dacie enjoyed working in the laboratory, and devising simple tests to assist in diagnosis and research. He never felt quite at home with the advancing development of automated instruments and computers in the laboratory, but time and again he was able to demonstrate his mastery in diagnosis with much simpler manual procedures.

His appreciation of the role of the laboratory led him to publish a short treatise entitled Practical Haematology (1950); later, co-authored with S.M. Lewis, this expanded into Dacie and Lewis' Practical Haematology, which has been translated into several languages, becoming the standard textbook on the subject in many countries, and is now in its ninth edition.

Dacie's influence on haematology was further extended by his distinguished editorship of the British Journal of Haematology, which was launched by Blackwell's in 1955, with Dacie its first editor. His dedication and insistence on an impeccable standard ensured that the journal quickly acquired an international reputation. When he relinquished the editorship in 1962 he remained as chairman of the editorial board, providing valued advice to the six editors who successively took up the mantle.

Dacie was elected FRCP in 1956 and FRS in 1967, and knighted in 1976. He was a foundation Fellow of the Royal College of Pathologists and President of the college in 1973-75. He was President of the Royal Society of Medicine in 1977-78. He was one of the founders of the British Society for Haematology, and its President in 1964. He was also President of the European-African Division of the International Society of Haematology for its Congress in London in 1975.

In setting the highest professional standards for himself and others, Dacie tended to be somewhat authoritarian in his role as a committee chairman, but he was always fair-minded. Within his department he was outstanding in his respect of academic freedom for his staff and research fellows. He would guide but would never take over, and he would not have his name attached to any paper if he had not made a significant contribution and been personally responsible for its writing.

At home he had a passion for music, gardening and entomology. He was especially pleased to invite selected visitors to inspect his display of Lepidoptera. Although this was just a hobby, he had mastered it with scholarly and scientific aptitude; with ever-increasing zeal he made sure that his net accompanied him on his holidays and in spare moments during professional visits and lecture tours. He was proud to have become a member of the British Entomological Society, with three papers published in the Entomologists' Record.

John Dacie married Margaret Thynne in 1938 and they had five children, two becoming doctors; one son predeceased him. For over 60 years Margaret gave him total companionship and support in his endeavours, extending even to accompanying him on moth-hunting expeditions at dawn on Wimbledon Common, whilst, when his retirement had deprived him of a secretary, she found time to type all his writings on their faithful Remington typewriter (not for him the newfangled word processor).

For some years after retirement he continued to pursue his hobbies with characteristic enthusiasm, erudition and technical proficiency. More recently, he restricted himself to the role of proud grandfather, listening to music, and he admitted to watching television snooker.

Mitchell Lewis