Smoking is associated with chronic kidney disease, presumably through its association with general vascular disease but also because smoking transiently increases blood pressure and decreases GFR. So that’s a good reason to quit but a recent article in the American Journal of Kidney Disease by Nogueira and colleagues examined the association between smoking and transplant outcomes in people receiving a living donor transplant. Both transplant and patient survival in smokers was lower than in non-smokers and transplant loss was significantly higher in current smokers. Intriguingly, the risk of acute rejection early after transplant was higher in smokers.
Over the past 25 years since I was a transplant registrar, immunosuppressive regimes have evolved and there’s been a dramatic reduction in acute rejection rates. Unfortunately, long term transplant survival has not improved to the same extent. Many factors contribute to diminished long term transplant outcomes, including chronic allograft nephropathy, recurrence of original disease, hypertension and viral infections: additionally, death with a functioning transplant due to, for instance, smoking related vascular disease should also be considered a poor transplant outcome and remains a major challenge for kidney care.
Some other studies have also found that smoking is a associated with decreased transplant survival and some have shown that in smokers there is increased fibrosis changes in the small arteries of the kidney transplant. It’s not clear how smoking increases acute rejection but that does pose several difficult management questions; for example should we intensify the early immunosuppressive regime in smokers or should we perform management biopsies early to detect sub-clinical rejection? If we intensify immunosuppressive regimes, patients may pay the price later with more infectious complications or even cancers.
There’s some good data to show better outcomes in people who quit smoking prior to transplantation and on the day that it was reported that the smoking ban in the United Kingdom led to a greater than 2% fall in heart attack rates in its first year, these reports on kidney disease and transplantation mean that we should intensify our efforts to counsel people with kidney disease about smoking and provide tangible support and encouragement for patients to enrol in smoking cessation schemes which have considerable success even in long term smokers.
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