Chronic Kidney Disease (CKD): Causes

00:01 So let's talk about some of the most common causes of chronic kidney disease that you're going to encounter.

00:07 And when I do this, I really like to subdivide them into the different parts of the Nephron that are different parts of the kidney that are affected.

00:14 So that includes the tubules and interstitium the vascular component of the kidney the glomerular component of the kidney and then post renal parts of the kidney, which means that there's a process going on anywhere from the renal pelvis to the bladder.

00:30 So we'll start out with the tubules and interstitium.

00:35 So some of the most common diseases that you'll see is polycystic kidney disease.

00:40 Polycystic kidney disease is probably the number one genetic disease that we see in our adult population.

00:47 It's autosomal dominant and it presents again in adulthood.

00:50 It's associated with a PKD 1 + PKD 2 mutations.

00:55 That's poly system one and poly system 2 and what that means is these genes actually encode for cilia on the epithelial cells.

01:05 Again, it's the most common cause of genetic kidney disease that we see certainly in the adult population and it's a disease that really has progression these patients when they're diagnosed with polycystic kidney disease will progress likely to the need of renal replacement therapy.

01:21 Certainly if there are PKD 1 mutation meaning that they're going to need dialysis or transplant and although we do have some therapies available that can slow progression.

01:31 We don't have anything that can cure this disease as of yet.

01:35 Now there's also an autosomal recessive variant and that typically is going to present in childhood So my pediatric Nephrology colleague see these people more common than I do.

01:44 It's also referred to as infantile polycystic kidney disease and that's associated with cystic dilatation of the collecting duct and congenital hepatic fibrosis.

01:52 Most of the time by the time these patients come to me and see me in my clinic.

01:56 They've already been transplanted both with the kidney and liver transplant.

02:00 Another category of tubuleinterstitial diseases that we have to think about are the some of the autoimmune diseases.

02:06 This includes things like Sjogren's syndrome, if you remember Sjogren's syndrome is associated with seckel syndrome, that means dryness.

02:12 So patients will manifest with destructions to the lacrimal and salivary glands and its associated with a polyclonal B Cell Activation.

02:20 Sarcoidosis is another autoimmune disease that we need to worry about that can cause tubule interstitial disease.

02:26 And remember this is really kind of defined by these non non-caseating granulomas as shown in our top figure over here.

02:34 And that bottom figure has a beautiful giant cell that we can see also in sarcoidosis.

02:40 Both of these are really marked by an inflammatory infiltrate in that tubuloininterstitium.

02:46 In the case of Sjogren's syndrome, I tend to get a lympho plasmacyric infiltrate and in the case of sarcoidosis as seen here, I get a lymphocytic infiltrate with these kind of beautiful non-caseating granulomas and those giant cells as well.

03:00 And because of this and because of where these inflammatory infiltrates are our patients often will manifest with tubular dysfunction.

03:10 So another tubulin are still disease to think about is something like reflex nephropathy.

03:15 We can see this in our pediatric population who have vesicle ureter reflux.

03:19 And that means that they have passage of urine from the bladder to the upper urinary tract and although some people will think about this as obstructive uropathy or a post renal disease because that urine is refluxing into that renal pelvis and into the cortex, then we end up having damage and inflammatory infiltrates in that cortical part of the kidney and that's really how that manifests more as tubuloininterstitial disease.

03:41 So again when we see reflux nephropathy this is typically due to inadequate closure of the ureterovesical junction almost seen exclusively in our pediatric population.

03:54 Okay.

03:54 So those are probably some of the most important disease processes that you're going to see in the tubular interstitial category that will present as chronic kidney disease.

04:03 Let's move on to the vascular compartment of our kidney.

04:07 So one of the biggest diseases to really think about is something called hypertensive vasculopathy.

04:14 So this is associated with chronic hypertension or hypertensive nephrosclerosis.

04:18 So very common the number two cause of people being on dialysis in the United States.

04:24 And what we see pathologically is these patients have an intimal thickening and luminal narrowing of their large and small renal arteries and glomerular arterioles.

04:33 We can also see renal vascular disease and we're going to talk about this in our secondary hypertension lecture and this is can be due to either having bilateral or unilateral renal artery stenosis and you can see this image here is actually a renal angiogram of a patient who has fibromuscular dysplasia.

04:49 So they have renal artery stenosis from their fmd and they actually are doing an angiogram where they're doing percutaneous transluminal angioplasty to actually balloon up that area of stenosis, which is one of the treatments for our patients who have fmd.

05:03 And again, we'll talk a little bit more about that when we get to our secondary hypertension lecture.

05:09 Another category of vascular disease is renal atheroembolic disease.

05:13 So we also talked about this in our acute kidney injury lecture.

05:16 But again, what happens here is we have these cholesterol emboli that embolize distally and it's caused by either having coronary, aortic or renal artery manipulation.

05:29 So again, it's also a cause of acute kidney injury, but the unfortunate part is that many of our patients don't recover function and renal atheroembolic disease ends up manisfesting and progressing to chronic kidney disease.

05:43 So let's move on to our next part of the kidney, which is the glomerular part and glomerular diseases.

05:49 So the number 1 common disease in the glimmer of the compartment and actually the most common cause of CKD and end-stage renal disease in the U.S.

05:57 is diabetic nephropathy.

06:00 So we're going to focus a little bit more closely on this later in the lecture.

06:03 But what I want you to notice here in are pathological image.

06:06 This is a patient who has diabetic nephropathy and you can really see what that arrow is pointing to which is a diabetic nodule that means at that mesangial area is actually really filled with mesangial matrix very acellular and patients tend to get a very nodular glomerular sclerosis.

06:25 Other diseases at the glomerulus also manifest with glomerular disease.

06:29 So these are some of our primary diseases and we're going to be talking about these as well as diabetes in our nephritic and nephrotic disease lecture.

06:38 Okay moving on to the last portion is really the post renal portion and we talked a little bit about this before in our AKI lecture, but this really occurs when there's prolonged obstruction of urine anywhere from that renal pelvis to the urethra.

06:54 And when we have prolonged obstruction without intervention, we can actually end up with parenchymal loss in the kidney.

07:01 So you end up losing nephron mass because of that compression for reflux of urine back into that renal pelvis.

07:07 And these are going to include conditions like benign prostatic hyperplasia.

07:13 It's going to include things like urethral strictures chronic obstructive calculi nephrolithiasis or stones in particular these big staghorn calculi that take up the entire renal pelvis or pelvic masses that can cause either intra or extra renal compression of the ureters.