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Professor Sir Peter Lachmann, FRS, FMedSci 1931 – 2020

The BSI was saddened to learn about the recent death of our Honorary Member, Professor Sir Peter Lachmann. He had been a member of the British Society for Immunology for over 15 years, making significant contributions to the field over decades.


Professor Sir Peter Lachmann died peacefully and at home on 26 December 2020. With his passing we have lost a giant of UK Immunology, a polymath with encyclopaedic knowledge and expertise crossing most areas of science, but who always considered himself an immunologist.

Best known for his seminal contributions to understanding of the complement system, an unfashionable backwater of immunology for much of his early career, Peter always sought to marry lab observations to clinical disease. In the 1960s and 1970s, he showed the importance of complement dysregulation in diverse autoimmune diseases, demonstrated the clinical impact of different complement deficiencies and showed the importance of nephritic factors, autoantibodies targeting the complement enzymes, as triggers for complement dysregulation in disease. In an early example of ‘bedside-to-bench’ research, he used these clinical observations to guide experiments that formed the basis of his ‘C3 tickover hypothesis’, published with little fanfare in the BSI’s house journals, Immunology and Clinical & Experimental Immunology in 1973 and 1975 respectively. These discoveries changed understanding of how complement was activated and amplified, key to its roles in disease and critical for current efforts at therapeutic modulation in disease.

More recently, Peter was also involved in the discovery and characterisation of CD59; I was fortunate enough to collaborate with him on these studies and learned much from the experience. True to form, when the ‘landmark’ paper on our CD59 work was ready for publication, Peter decided that Immunology was the right journal because the right people read it! Peter ‘retired’, in 1997 but continued to lead a small research team focused on therapeutic modulation of the amplification loop of complement, a highly productive period that included cofounding a company in his ninth decade.

Peter was an inspiration and mentor to many, including me. Indeed, I first ‘properly’ encountered Peter in 1984 when he travelled to Cardiff to examine my PhD – I was terrified! After four hours of interrogation, he called a truce, slapped me on the back and said ‘that was fun’ – and I think he meant it! He was hugely supportive of students, junior staff and fellows and would always be ready with advice, a letter of support or a dose of mentoring of the ‘old school’ kind. He was a delight to debate with (as long as you didn’t expect to win), a font of knowledge and incredibly generous with his time and patronage. His contributions at conferences (remember those?) were legendary – always installed in the front row and ready with ‘killer’ questions or comments that cut to the heart of the issue, but also the first to offer advice, support and a pat on the back at the coffee break.

There was much more to Peter than his research. A shrewd politician, he made significant and lasting changes to UK Science. Notable among many was his role in establishing the Academy of Medical Sciences – appointed in 1998 as first President, he set the Academy on the path to its current position as a world-leading Medical Sciences Academy.

Peter will be greatly missed by many in the UK immunology community and beyond. I have lost a friend and mentor of over 35 years. I look forward to celebrating this great life with the many others he touched over his remarkable career when circumstances allow.

Paul Morgan