Anasarca, swellling & the nephrotic syndrome

Today's Pearls:

1. Swelling

2. An edema framework

3. The nephrotic syndrome

On Monday this week: Cody presented a 65 yo with anasarca. 

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During the exploration of this case we discussed how the description & distribution of swelling changes the differential. 

Pitting Edema: We all know this one when we see it!

Borrowed from : http://www.med-health.net/Edema-Grading.html.

Myxedema: Nonpitting! Occurs due to accumulation of glycosaminoglycans.

Lymphadema: Thickened fibrous skin. Can be upper or lower extremities.

Look for Stemmer's sign: inability to pinch/tent the skin at the base of a digit. This is a sign you are dealing with lymphadema.

 https://www.pinterest.com/pin/677158493948242337/?lp=true 

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An Edema Framework

This flowchart is not exhaustive but does nicely break down the causes of edema by mechanism.

https://accessmedicine.mhmedical.com/content.aspx?bookid=500&sectionid=41026577

Our patient had an albumin of 1.5 and a 24 protein excretion measured at > 4g both consistent with nephrotic syndrome.

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The Nephrotic Syndrome

Edema. Proteinuria (> 3g). Hyperlipidema.

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Focal Segmental Glomerulosclerosis: 

• Incidence of 1 in 100,000
• Pathophysiology: podocytes detach & die leading to ares of sclerosis

Causes:

• Autoimmunologic: host leukocytes produce "factors" that attack the podocyte. Because of this FSGS can recur in patient's who undergo renal transplant (in the transplanted kidney). 
• Genetics: APOL1 gene implicated.
• Hyperfiltration: obesity, solitary kidney, premature birth

Diagnosis: KIDNEY BIOPSY!

Treatment: 

• ACEi
• Steroids

50% of patients will progress to ESRD in 10 years. 😟

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Membranous Glomerulonephritis

• Incidence 1 per 100,000
• Onset between 30 & 50 years of age.

Causes:

• Primary: Anti-PLA2R antibodies attack the podocytes
• Secondary: SLE, hep B, malignancy (***if found patient's need cancer screening***)

Diagnosis: KIDNEY BIOPSY!

Treatment: if primary disease (if secondary, the underlying cause should be treated)

• Initial treatment is conservative (for 6-12 months): ACEi or ARB + Statin
• If diseases is persistent patients will be treated with: Steroids + alkylating agents (cyclophosphamide) or calcineurin inhibitors (cyclosporine or tacrolimus)

Prognosis: 

• Some patients will have spontaneous improvement without aggressive therapy. 
• ~ 75% of patients treated with the above regiments will achieve remission. Of course, relapse does occur. 
• Progression to ESRD is variable.  

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Minimal Change Glomerulopathy 

• Most common cause in children.
• Causes 10-15% of nephrotic syndrome in adults.
• Patients are older, > 65 yrs.

Causes:

• Primary: Anti-PLA2R antibodies attack the podocytes
• Secondary: Hodgkin's, NHL, allergy, infection(syphillis, mycoplasma, ehrlichiosis, strongyloides), meds (NSAIDs, lithium).

Diagnosis: KIDNEY BIOPSY!

Treatment: 

1. Steroids
2. Steroids resistant or relapsing diseases is treated with: mycophenolate mofetil, alkylating agents (cyclophosphamide), rituximab & calcineurin inhibitors (cyclosporine, tacrolimus)

Prognosis: 

• 90% of patients achieve remission with steroids

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Diabetic Nephropathy

• Most common cause of kidney disease worldwide.
• Occurs after many years of disease & is usually proceeded by microalbuminuria.
• Seen with other late stages of diabetic microvascular disease (retinopathy, neuropathy) & macrovascular disease (stroke, MI, PVD)

Diagnosis: Clinical + microalbuminuria testing.

Treatment: 

1. Blood sugar control
2. ACEi or ARB at the maximal tolerated dose

The above information was summarized for learning purposes from MKSAP & Uptodate.


Prepared by: Emma White