Can urine routine test detect kidney disease?

A routine urine test can actually help us understand kidney problems. If the protein in the urine is too high during a routine urine test, it may indicate the impact of nephritis, kidney disease or high blood pressure, so a routine urine test is naturally essential. Of course, in addition to these examination methods, other clinical symptoms must also be combined to make a clear judgment and clarify the symptomatic treatment of the disease.

1. Inspection significance

The presence of protein in the urine indicates possible kidney problems, which is generally seen in various stages of nephritis, kidney disease, hypertension, renal artery sclerosis, renal tuberculosis, kidney stones, renal amyloid degeneration, etc. In addition to proteinuria, kidney disease generally has other symptoms and signs, such as abnormal kidney color Doppler ultrasound, edema, hypertension, etc. It is recommended to combine clinical symptoms for relevant examinations to clarify the diagnosis and symptomatic treatment.

2. Inspection Methods

(1) Urinalysis: In simple nephropathy, the qualitative urine protein is mostly positive; the 24-hour quantitative urine protein exceeds 0.1 g/kg, and occasionally there is a small amount of red blood cells temporarily. In addition to varying degrees of proteinuria, nephritic nephropathy may also present with microscopic or macroscopic hematuria.

(2) Blood biochemical tests showed hypoproteinemia (serum albumin <30 g/L, infants <25 g/L), an inverted albumin to globulin ratio, and serum protein electrophoresis showed increased globulin; blood cholesterol was significantly increased (>5.7 mmol/L for children and >5.1 mmol/L for infants).

(3) Renal function test: There may be temporary mild azotemia during the oliguria phase, while renal function is usually normal in patients with simple nephropathy. If there is varying degrees of renal insufficiency and elevated blood creatinine and urea nitrogen, it indicates nephritic kidney disease.

(4) Serum complement measurement helps to distinguish simple nephropathy from nephritic nephropathy. The former has normal serum complement, while the latter often has varying degrees of hypocomplementemia and a continuous decrease in C3.

(5) Serum and urine protein electrophoresis can reflect the selectivity of urine protein by detecting the IgG component in urine. It can also distinguish pseudo-massive proteinuria from light-chain proteinuria. If the ratio of gamma globulin to albumin in urine is less than 0.1, it is selective proteinuria (indicating simple nephropathy), and if it is greater than 0.5, it is non-selective proteinuria, indicating nephritic nephropathy.

(6) Serum immunological examination: Detection of antinuclear antibodies, anti-double-stranded DNA antibodies, anti-Sm antibodies, anti-rnp antibodies, anti-histone antibodies, hepatitis B virus markers, rheumatoid factor, circulating immune complexes, etc., to distinguish between primary and secondary nephrotic syndrome.

(7) Detection of proteins related to coagulation and fibrinolysis, such as fibrinogen and factors V, VII, VIII and X, antithrombin III, and urinary fibrin degradation products (FDP), can reflect the body's coagulation state and provide a basis for whether to adopt anticoagulant treatment.