In 1914, Volhard and Fahr (1) described the first-ever classification of glomerular diseases. It was simple: inflammatory, degenerative, or related to arteriosclerosis (Table 1). Since then, diseases of the glomerulus have always held a special place of interest for nephrologists. On closer inspection, the science and knowledge of the glomerulus have revealed much of the beauty and complexity of this structure. From the 1900s to 2021, we have come a long way with advances in genetics in the discovery of APOL1 polymorphisms associated with focal segmental glomerulosclerosis (FSGS), multiple monogenic causes of FSGS and other primary kidney diseases, autoantibodies directed toward the phospholipase A2 receptor and others in membranous nephropathy, newer classifications of membranoproliferative glomerulonephritis (MPGN), novel treatments for lupus nephritis and antineutrophil cytoplasmic antibody (ANCA) vasculitis, defining C3 glomerulonephritis (C3GN), and better understanding of paraprotein-mediated glomerular diseases, and the list goes on and on. In this issue of Kidney News, we highlight some common glomerular diseases and their updated pathophysiology and treatment strategies, but we also highlight some rarer disease states and novel associations with infections and autoimmune diseases.
Here is a countdown of the top 10 reasons why we think nephrologists love the glomerulus:
10 Rapidly progressive glomerular nephrologists (RPGNs) are the immunologists among nephrologists.
9 The epithelial cell of the glomerulus is called the podocyte. Its name is derived from the foot-like projections (pedicels). Maybe glomerular specialists should be called podocytologists.
8 Electron microscopy pictures make great Zoom backgrounds; welcome to the “art” of nephrology.
7 The colorful histopathology slides make us and the nephropathologists smile.
6 You don’t have to worry about the “math” of nephrology; the calculations you do for acid–base and electrolyte disorders don’t haunt you in glomerular diseases.
5 It is ever evolving with newer molecules for treatment, newer diagnostic approaches, and newer disease definitions. (Remember how we changed the MPGN classification and welcomed C3GN?)
4 We stay grounded when we deal with them—old is gold! (A glomerular nephrologist is nothing without the simple humble and oldest tool in nephrology: a urinary examination.)
3 Many times, the glomerular disorder can be successfully treated and remission achieved.
2 Novel treatment options are rapidly emerging to treat various glomerular disorders. By 2030, we may also be using therapeutic agents with names that are hard to pronounce (e.g., namemelongxxxyyzzyAB).
1 Dealing with a glomerular nephrologist is like solving a puzzle: the history, the urine picture, the serology, making a mental differential diagnosis list. Then the curtains rise with the climax of the kidney biopsy, and then the treatment options, and then the response.… It makes us feel like a detective!
Figure above created using BioRender (biorender.com)