Protein and casts in urine

Introduction Under normal circumstances, due to the filtration of glomerular filtration membrane and the reabsorption of renal tubules, the amount of protein in the urine of healthy people (multiple molecular weight proteins) is very small (less than 150 mg per day) ), when the protein is qualitatively tested, it is negative. In pathological conditions, such as with kidney disease, the filtration of the filtration membrane changes. One of the typical diagnostic criteria for chronic nephritis, purpuric nephritis, lupus nephritis, and diabetic nephropathy is the abnormality of proteinuria and hematuria at the time of routine urine examination, and is highly suspected of kidney disease.

Cause

1, acute glomerulonephritis, various types of chronic glomerulonephritis, IgA nephritis, occult nephritis.

2, secondary to autoimmune diseases such as lupus kidney, diabetic nephropathy, purpuric nephritis, renal arteriosclerosis and so on.

3, urinary tract infection, urinary tract epithelial cell shedding and urinary secretion of mucin.

an examination

Related inspection

Urine sediment tube type examination urine routine urine protein quantification

(1) medical history

Such as history of edema, occurrence of hypertension, history of diabetes, history of allergic purpura, history of drug use in damaged kidneys, history of heavy metal salt poisoning, history of connective tissue disease, history of metabolic diseases and gout attacks.

(B) physical examination of proteinuria

Pay attention to edema and serous effusion, bone and joint examination, degree of anemia and examination of heart, liver and kidney signs.

Fundus examination, normal nephritis, normal or mild vasospasm, chronic nephritis, fundus arteriosclerosis, hemorrhage, exudation, etc. Diabetic nephropathy often has diabetic fundus.

(3) Laboratory examination of proteinuria

Urine protein examination can be divided into qualitative, quantitative and special examinations.

Qualitative inspection

It is best to have morning urine, the morning urine is the strongest, and the orthostatic proteinuria can be ruled out. Qualitative examination is only a screening test, not as an accurate indicator of urine protein content.

2. Quantitative examination of urine protein

3. Urine protein special examination

Urine protein electrophoresis can distinguish between selective proteinuria and non-selective proteinuria. Urine protein electrophoresis of multiple myeloma is helpful for typing.

Radioimmunoassay is helpful in the diagnosis of early renal tubular dysfunction.

Differential diagnosis

Protein and casticular symptoms in the urine need to be distinguished from the following symptoms.

(a) acute glomerulonephritis

After streptococcal infection, edema, hypertension, hematuria, proteinuria, and tubular urine appear.

(two) chronic glomerulonephritis

Edema starts from the lower limbs and spreads from the bottom to the top. It has a long course of disease and is prone to recurrence. In the late stage, renal function damage often occurs, and hypertension is the earliest.

(c) pyelonephritis

Symptoms of systemic infection, low back pain, bladder irritation, and laboratory tests for pyuria.

(4) Systemic lupus erythematosus is an autoimmune disease, hair loss, facial butterfly erythema, oral ulcer, migratory arthritis, photoallergic, Raynaud's phenomenon, and multiple organ damage, especially in the heart and kidney. Loss first.

Its proteinuria is generally more, and some patients appear in the form of nephrotic syndrome.

(5) Multiple myeloma

Older men have a good hair, anemia is heavy and not commensurate with kidney damage. The disease progresses rapidly and is easy to damage kidney function, bone destruction, bone pain, and pathological fracture. Its urine protein is spilled proteinuria.

(6) Others

Severe exercise, microalbuminuria, fever, proteinuria, heart failure, renal congestion, proteinuria, drug poisoning, proteinuria, due to a clear history and corresponding physical examination, general diagnosis is not difficult.

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