Syndromes of Renal Disease

1.       Acute nephritic syndrome

§         Macroscopic or microscopic hematuria (macroscopic is frank blood in the urine, whereas microscopic is when the urine may seem red but you have to spin down the urine to find the RBCs)

§         Edema (mostly periorbital, but also generalized)

§         Oliguria (<400 ml/day)

§         Hypertension (due to Na and H2O retention)

§         Mild to moderate proteinuria (>3.5 g/day) (note: once Dr. Reddi had a patient with a bacterial infection that caused acute nephritic syndrome, and they had very  very high protein in the urine, but normally this disease presents with only mild protein in the urine)

2.       Nephrotic syndrome

§         Proteinuria (>3.5 g/day)

§         Edema

§         Hypoalbuminemia (b/c loss of albumin into urine)

§         Hyperlipidemia

§         Lipiduria (b/c loss of other lipoproteins into urine)

3.       Asymptomatic urinary abnormalities

§         Isolated hematuria (*Dr. Reddi said not to forget this one in our differential diagnoses!)

i.           Caused by 3 more serious diseases that must be referred to the nephrologists:

1.   IgA nephropathy

2.    Alport’s syndrome

3.    thin basement membrane disease

ii.        Patient history and biopsy used to differentiate b/w the 3 conditions.

 

§         Orthostatic proteinuria *

i.  This condition is when a person has high protein in the urine when in the upright position but none in the supine position. (>3.5 g/day)

ii.  Common in young adults (18-30 yrs)

iii.  Diagnosis: Collect urine after patient has been on his feet all day (7am – 7pm) and compare to protein values after sleeping/laying down at night (8pm – 6am)

iv.  Prognosis: Good - this is a benign condition.  No biopsy is needed and no referral needed for a nephrologist!  This is important to document in a patient’s chart so that later on another physician doesn’t waste time, money & resources investigating renal disease if that patient has this benign condition.

4.       Acute renal failure

§         Syndrome characterized by rapid increases in serum creatinine & BUN levels in a few hours or days.

§         This is commonly seen in diabetic patients.

§         Some major causes include prerenal azotemia, intrinsic renal diseases, and urinary tract obstruction.

5.       Chronic Renal Failure (Chronic kidney disease)

§         Unlike acute renal failure, this develops over a much longer time period, like several months to years.

§         Diabetes is the leading cause of this disease.

§         When a patient is at the point in the progression of the disease, they will require dialysis – this is very expensive, so one of our many goals as physicians is to take prevent the progression of kidney disease to such a chronic state that one would require dialysis.

§         As physicians, we should understand the pathophysiology of disease to properly treat it, and prevent progression to end stage diseases such as this one.

6.       Tubulointerstitial diseases (TIDs) aka interstitial renal disease

§       This is a group of clinical disorders that affect mainly the renal tubules & interstitium. (not the glomeruli nor the renal vasculature).

§       The disorders are divided into 2 groups, depending on their morphologic changes & rate of deterioration of renal functions  acute & chronic!  (who would’ve guessed?!)

§       Primary TIDs, caused mostly by antibiotics, may be responsible for 15% of all cases of acute renal failure and 25% of end stage renal disease.

§       Secondary to TIDs is a disease known as focal segmental glomerulosclerosis…don’t worry, we’ll learn more about this very very soon!

7.       Vascular diseases

§        This group of diseases affect the renal vasculature and include:

o       Atherosclerotic renal vascular disease (Aka renal artery stenosis – remember Dr. Gerula talked about this as a cause of secondary hypertension last unit; this is very common, and causes uncontrolled BP that needs 4 or 5 anti-hypertensive medications to control!)

o      Hypertensive renal vascular diseases (hypertensive nephrosclerosis – Dr. Cleveland talked about this one!)

o      Systemic vasculitis (Wegener’s granulomatous disease – mentioned before too; this diseases usually requires lifelong treatment)

o      Microangiopathic diseases (hemolytic uremic syndrome & thrombotic thrombocytopenic purpura TTP – TTP requires plasmasphoresis)

o      Renal vein thrombosis (usually a complication of nepthrotic sydnrome)

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