Register now or log in to join your professional community.
بروتين يظهر في البول على شكل راسب ابيض عند تسخين البول لدرجة 60 مئوية ويدل عن وجود سرطان multiple myeloma ويعزز هذا الفحص باجراء الترحيل الكهربائي لبروتينات الدم معطيا شكل حرف ام بالانكليزي ويعرف ب M-band
بسبب انتاج بروتين غير سليم يضهر على شكل قطعة احادية النسيله او على شكل سلسله خفيفة
Itis important to diagnosis of multiple myelloma(B cell lymphoma), lymphoblastic leukemia, some bones diseases. itis apper in urine as low molecular weight protein.
Bence-Jones protein in urine used mainly to diagnose and monitor multiple myeloma, a blood cancer. An abnormal Bence-Jones test result is also linked with malignant lymphomas, which are cancers of the lymphatic system
Bence Jones Protein Test
Definition
Bence Jones proteins are small proteins (light chains of immunoblobulin) found in the urine. Testing for these proteins is done to diagnose and monitor multiple myeloma and other similar diseases.
Purpose
Bence Jones proteins are considered the first tumor marker. A tumor marker is a substance, made by the body, that is linked to a certain cancer, or malignancy. Bence Jones proteins are made by plasma cells, a type of white blood cell. The presence of these proteins in a person's urine is associated with a malignancy of plasma cells.
Multiple myeloma, a tumor of plasma cells, is the disease most often linked with Bence Jones proteins. The amount of Bence Jones proteins in the urine indicates how much tumor is present. Physicians use Bence Jones proteins testing to diagnose the disease as well as to check how well the disease is responding to treatment.
Description
Urine is the best specimen in which to look for Bence Jones proteins. Proteins are usually too large to move through a healthy kidney, from the blood into the urine. Bence Jones proteins are an exception. They are small enough to move quickly and easily through the kidney into the urine.
A routine urinalysis will not detect Bence Jones proteins. There are several methods used by laboratories to detect and measure these proteins. The classic Bence Jones reaction involves heating urine to140°F (60°C). At this temperature, the Bence Jones proteins will clump. The clumping disappears if the urine is further heated to boiling and reappears when the urine is cooled. Other clumping procedures using salts, acids, and other chemicals are also used to detect these proteins. These types of test will reveal whether or not Bence Jones proteins are present, but not how much is present.
A more complex procedure is done to measure the exact amount of Bence Jones proteins. This procedure—immunoelectrophoresis—is usually done on urine that has been collected for24-hours.
Preparation
Urine is usually collected throughout a24-hour time period. A person is given a large container in which to collect the urine. The urine should be refrigerated until it is brought to the laboratory or physician's office.
Normal results
Bence Jones proteins normally are not present in the urine.
Abnormal results
Bence Jones proteins are present in50-80% of people with multiple myeloma. People with other malignancies also can have a positive Bence Jones proteins test, but less frequently.
Certain nonmalignant diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and chronic renal insufficiency, can have Bence Jones proteins in the urine. High doses of penicillin or aspirin before collecting the urine can give a false positive result.
Resources
Books
Pagana, Kathleen Deska. Mosby's Manual of Diagnostic and Laboratory Tests. St. Louis: Mosby, Inc.,1998.
يتكون بروتين بنس جونز من السلاسل الخفيفة (كابا و لامدا) للاجسام المضادة (الجلوبيولين المناعي)و الذي يفرز من الخلايا البلازمية الغير طبيعية في الورم النقوي المتعدد.
بنس جونس بروتين عبارة عن بروتين صغير جدا ينتج دايما من تحطم احد اللايت جين المتواجدة في الايمنوقلوبيلين التي تفرزها خلايا البلازما ونسبتة لصغره يتخطي الكليه ويظهر في البول او نتيجة للفشل الكلوي .
