Jan 25, 2021

In memoriam: Arthur Leznoff

Clinical Immunology & Allergy
Dr. Arthur Leznoff

Dr. Arthur Leznoff, former Division Head of Clinical Immunology and Allergy at St. Michael’s Hospital, passed away on Jan. 15, 2021. He joined St. Michael’s as a staff physician in 1971, and up until the time of the merger with the Wellesley Hospital, Dr. Leznoff was the Head of the Division of Allergy and Clinical Immunology; he retired in 2005. Dr. Leznoff completed medical school at McGill University, general internal medicine residency in Chicago and allergy and immunology training in Montreal.

Over the course of his career, Dr. Leznoff was highly regarded throughout the University of Toronto and the country for his expertise in clinical immunology and his leadership in the development of the field as an academic specialty. In 1976, he was promoted to associate professor and won the Gerald Wong Award for being an outstanding undergraduate teacher in the Department of Medicine in 1996 and the Squires Award for his overall educational contribution in 2003. In 2005, Dr. Leznoff received the title of Honorary Consultant at St. Michael’s from the Medical Advisory Committee.


Reflections from Dr Leznoff’s close colleagues and friends:

Dr. Arthur Leznoff was the epitome of the kind, caring and knowledgeable physician: a true gentleman. He was well-respected by colleagues, trainees and patients alike. I came to know him as a teacher, mentor, colleague, and, over the years, a dear friend.

He completed medical school at McGill, did residency training in Chicago, and began his career in Montréal. In addition to a busy practice in clinical immunology and allergy, he was active in teaching and research, with publications covering many different aspects in his field. Early in his career he focused on histoplasmosis in Montréal, made important contributions regarding the safety of long-term corticosteroid use in asthma, and respiratory disease in grain elevator workers. He moved to Toronto and joined St. Michael's Hospital in the early 1970s where he became Head of our division for many years. He contributed to the recognition of chronic urticaria as an autoimmune phenomenon, and with others, reported its association with autoimmune thyroid disease. His contributions in chronic urticaria and hereditary angioedema continued throughout his career.  He developed expertise in treating inflammatory ocular disorders, and later, his research focused on multiple chemical sensitivity (now known as idiopathic environmental intolerance), showing that in many cases, symptoms were not due to toxicity, but to anticipatory anxiety and hyperventilation.

My first contact with Dr. Leznoff was in undergraduate medical school, when he gave a few lectures on allergy and immunology. He always swore to the class that there would be an exam question on cross-reactivity between aspirin and NSAIDs, so we would always remember this important fact, and he was true to his word. The question always appeared on the exam every year he lectured on the subject. Later, it was an honest and detailed discussion with him that made me decide to choose Allergy and Immunology as a specialty, and to work at St. Michael's Hospital when I finished my training, where I was lucky enough to join him in clinical practice and research endeavors.

Other former trainees will remember his famous "weed walks", when we were taken outdoors to identify various allergenic plants, and how we were instructed to collect pollens outside our homes to identify under the microscope. Lunch always involved a banana and some tea, and there was a bag of sesame snaps in his desk drawer, the latter routinely offered to residents, while discussing cases. The bulletin board above his desk was filled with pictures of grandchildren, and there were discussions of planning holidays with his beloved wife, Ruth, visiting family in Vancouver and Florida. The trip from his office in the old Annex building on Shuter Street to the outpatient clinic on 4 CC invariably involved a foray up the oddly spaced stairs in the main part of the hospital, which he habitually took two at a time.

I always remember him with white hair, and a somewhat grandfatherly appearance, often with a mischievous twinkle in his eye when telling one of his many jokes or anecdotes.  He forever spoke and moved at a measured, deliberate pace which never wavered, and betrayed the lightning- fast wit, intelligence and encyclopedic knowledge behind the soft-spoken appearance. Throughout his life he maintained an active interest in his chosen profession and remained current with new developments in the molecular and cellular underpinnings of his clinical practice.

A true gentleman, he will be missed by family, friends, colleagues and patients.

— Dr. Karen Binkley

I first Dr Leznoff when I came on staff at Toronto General Hospital in 1977 and very well remember how kind and welcoming he was at that time and up until the last time I saw him at a meeting shortly before the pandemic.

He was an integral member of the Gage Research Institute (that later became part of the Dalla Lana Department of Public Health) in the 1970s-1990s, contributing to a combined inter-hospital, allergy and respirology clinic approach to asthma management and research. He also developed a strong interest in symptoms attributed to occupational allergy and had a regular clinic in the occupational medicine division of St Michael’s Hospital.

— Dr. Susan Tarlo