Investigations of a case of proteinuria:- Characterization of proteinuria: After diagnosis of proteinuria
by dip stick test, it should be confirmed by quantitative estimation
of 24 hours proteinuria. Further assessment may include
electrophoresis or immunoelectrophoresis to determine the type of
abnormal protein excreted. - Urine analysis: For pus cells (to diagnose U.T. infection), RBCs
and casts (to diagnose glomerular disease), also urine volume
(oliguria or polyuria), pH of urine, specific gravity and test for
glycosuria; and aminoaciduria and B 2 microglobulin (may help in
the diagnosis of tubular disease). - Blood and serologic examination:
a. Kidney function tests: serum creatinine, creatinine clearance,
electrolytes (Na, K, Ca, Po 4 ).
b. Total protein, albumin, cholesterol to diagnose nephrotic
syndrome.
c. Serologic examination e.g. for anti-DNA and complement
component C 3 and C 4 for diagnosis of lupus erythematosus. - Radiologic assessment including:
a. Examination of the kidney for its size, state of parenchyma, the
presence of stone, back pressure change or pyelonephritic
changes. It is achieved through ultrasound examination, plain
X-ray, and IVP (if the kidney function is normal).
b. Investigations to discover malignancy which could be the
etiologic cause of proteinuria e.g. skeletal survey for multiple
myeloma, X-ray chest and bronchogram or CT scan for
bronchogenic carcinoma.