Pediatric Glomerulonephritis

00:01 So let’s focus on what’s happening when we have an abnormal glomerulus and in particular, inflammation of the glomerulus which is glomerulonephritis.

00:11 As you recall from your histopathology, here’s a normal glomerulus and here’s an abnormal glomerulus and you can see it is heavily infiltrated with white blood cells and inflammatory cells.

00:23 So the inflammation of the glomerulus has many potential causes and it can in turn result in hematuria and proteinuria, red blood cell casts and that’s a great way to distinguish between glomerulonephritis and cystitis.

00:41 And sometimes can result in hypertension through abnormal renin secretion or even frank renal failure.

00:50 So glomerulonephritis which is blood and protein coming out, spilling out of the urine through that abnormal glomerulus can be broken down into a few categories.

01:03 It can be acute that usually has red blood cell casts and that acute glomerulonephritis maybe either primary, something wrong with the kidney, or secondary, something wrong systemically.

01:16 Alternatively, glomerulonephritis maybe chronic.

01:19 And in this case often, they are not red blood cell casts and with chronic disease, again this can be either primary or secondary.

01:29 So I want to go through examples of diseases that are either acute, primary and secondary or chronic, primary and secondary.

01:37 So let’s start with acute glomerulonephritis.

01:41 This is the one which often presents with red blood casts.

01:45 We have primary and secondary causes.

01:48 The primary causes include commonly post-strep glomerulonephritis.

01:53 Remember, that treatment of strep throat does not prevent post-strep glomerulonephritis like it does rheumatic fever.

02:01 It could be an infectious glomerulonephritis, basically a pyelonephritis, or it could be IgA nephropathy which is also called Berger’s disease.

02:11 Or it could be membranoproliferative glomerulonephritis or MPGN.

02:16 Secondary causes of acute glomerulonephritis are systemic problems that will acutely cause the kidneys to bleed.

02:26 The most common is Henoch-Schonlein purpura.

02:29 Also, lupus can do it or patients may have polyarteritis nodosa which is a systemic disease that can involve the kidneys.

02:38 Patients may have hemolytic uremic syndrome which absolutely causes renal damage.

02:43 This is what you got after getting bad strains of E. coli.

02:47 Patients may have subacute endocarditis which is flicking little clots which is damaging the kidney and causing acute bleeding.

02:55 Or patients may have something like Goodpasture syndrome which is an inflammation of the basement membrane in the kidney.

03:01 Chronic glomerulonephritis may result in significant bleeding.

03:08 This is an ongoing issue.

03:10 These patients typically don’t have casts and the primary causes include again membranoproliferative glomerulonephritis.

03:19 Patients may have membranous nephropathy.

03:22 They could have focal glomerulosclerosis or they may have mesangial proliferative nephritis.

03:28 Those are all chronic conditions that can cause a primary glomerulonephritis and a primary bleeding in the urine.

03:36 The secondary causes of chronic are the same as the first.

03:40 HSP may become chronic in those unfortunate patients who end up with longstanding renal disease, obviously lupus, polyarteritis nodosa, HUS, subacute endocarditis and Goodpasture syndrome.

03:53 This can all be chronic conditions.

03:55 So the diagnosis of glomerulonephritis, if you suspect it, is not always made by a biopsy.

04:03 We do not require biopsy in patients where there is clear explanation for the disease.

04:08 Examples would be post-strep glomerulonephritis where we knew the child had strep throat two weeks ago or the very obvious situational conditions of hemolytic uremic syndrome and Henoch-Schonlein purpura.

04:22 If you want to know more about these diseases, there are separate lectures on those.

04:26 We generally, for those diseases, target therapy towards the underlying problem as opposed to the kidneys.

04:34 We can check C3 and C4 levels and that can help us distinguish between some causes of glomerulonephritis.

04:43 This is important.

04:45 We typically see low C3 and normal C4 in post-strep glomerulonephritis.

04:53 However, we see low C3 and low C4 in lupus, shunt nephritis and bacterial endocarditis.

05:03 So lupus has a low C3 and low C4 and post-strep glomerulonephritis just a low C3.

05:12 So for those patients where you think it’s post-strep glomerulonephritis, you got a low C3 and a normal C4, that child probably does not require a biopsy.

05:22 The prognosis for glomerulonephritis in general is excellent.

05:28 Some of the diseases end up chronic but that’s the vast minority.

05:32 So 98% of children will make a full recovery whereas 2% will go on to have chronic renal failure or some form of chronic kidney disease.

05:42 That’s a summary of hematuria and glomerulonephritis.

05:46 Thanks for your attention.