From Structure to Function: The Organ Replacement Concept of the Kidney

Kidney transplantation is of particular interest from today’s perspective because it was with the kidney that organ transplantation resumed after 1945. In the early phase of transplant surgery, however, kidney transplants were an exception, because most transplants were done with organs of internal secretion. Like the adrenal gland, the kidney was one of the organs that had already been associated with a specific clinical picture in the context of pathological anatomy in the first half of the nineteenth century. When Richard Bright described an organ disease of the kidney for the first time in 1827, the combination of clinical observations with postmortem autopsy led him to associate a specific set of symptoms with specific structural changes in the organ.

Clinicians, however, had to deal with the functional dimension of the disease: their patients suffered from the clinical consequences of kidney failure, such as edemas and symptoms of uremia. In the last decade of the nineteenth and in the early twentieth centuries, doctors and scientists approached kidney diseases with the same functional methods they had used with success for diseases of the stomach or the heart. Function-related terms such as “kidney insufficiency” or “kidney failure” entered the discussion on Bright’s disease, and animal models served for research into the functional aspects of kidney diseases. In their experiments, scientists at first still focused mainly on the microscopic examination of tissues. This kind of “experimental pathology” lost its leading role after 1910 when functional diagnosis and laboratory analysis came to the fore. The newly introduced “clearance” concept made the degree of kidney failure quantifiable, and eventually an elevated serum creatinine level became synonymous with kidney disease, which was no longer equated primarily with shrunken organ tissue but with the loss of organ function. Ideas on kidney disease thus followed the contemporary shift of interest from structure to function.

It was also for functional reasons that the first kidney transplants were performed. At first, however, it was not the organ’s excretory function that raised hopes for a replacement therapy. In the 1890s some researchers tried to understand the kidney’s function and its diseases by attributing them to a hypothetical internal secretion of the organ.