Question

1. What is the normal range for plasma creatinine for a 70 kg man?

2. If a patient has a plasma [CR] = 3 mg/dL and has reddish-brown urine, what is his probable diagnosis?

3. Explain how plasma [CR] is related to this disorder.

4. What is responsible for the reddish-brown color?

Answer 1

1. Normal range of plasma creatinine in a healthy average man is 0.6-1.2 mg/dL.

2. If a patient has plasma creatinine 3.0 mg/dl and reddish brown urine, he is probably suffering from glomerulonephritis induced acute kidney injury.

3. Glomerulonephritis signifies glomerular inflammation due to immune mediated glomerular injury resulting in many symptoms which are collectively termed as nephritic syndrome. Nephritic syndrome features are : a) Haematuria(blood in urine)

b) Proteinuria (abnormal excretion of excess amount of protein in urine) c) Oliguria (Decrease in urine output)

d) Hypertension

e) Edema

f) Red blood cell cast (Deformed Red blood cell characteristic of glomerulonephritis)

g) Uremia: characterised by elevation in nitrogenous waste products such as blood urea nitrogen and creatinine .

4. Blood and Red blood cell casts in urine give reddish brown color to urine.

Explanation and discussion:

Inflammation of glomerular structure of nephron is termed as glomerulonephritis. Some of the common causes of glomerulonephritis are: 1)Poststreptococcal glomerulonephritis, 2) Systemic lupus erythematosus (SLE), 3) Goodpasture syndrome, 4) Wegner granulomatosis and 5) IgA nephropathy.

Abnormal deposition of immune complexes and failure to clear them is the main mechanism of developing glomerulonephritis causing kidney damage characterised by elevation of serum creatinine. Abnormal elevation of creatinine above the normal range in the absence of preexisting renal pathology is termed as acute kidney injury.

Glomerulonephritis presents as nephritic syndrome which is characterised by:

1) Nephritic range proteinuria- Proteinuria of less than 3.5 gram/ 24 hour

2) Blood and RBC casts giving urine reddish brown or dark brown color also termed as 'cola colored' urine

3) Hypertension

4) Edema - Swelling usually starting around eyes then gradually there is whole body swelling

5) Accumulation of nitrogenous waste products in blood due to renal dysfunction leading to symptoms such as nausea, vomiting, loss of appetite and itching termed as uremia.