How much do you know about the main clinical applications of specific proteins?

Today I’m going to introduce you to a specific protein, so what is a specific protein? Specific proteins, usually called special proteins, are proteins with specific functions that are derived from tissue cells and widely exist in serum, and perform various important biological functions. Many diseases can cause changes in serum proteins, and specific proteins have therefore become important clinical test indicators. Proteins have good antigenicity, and antigen-antibody reactions can be used to determine proteins with a specific antigenicity, so it is also called specific protein detection.

There are many types of specific proteins. Today, the editor of Desheng will tell you about the main clinical applications of specific proteins.

1. Immunoglobulin and complement series

The most common of specific proteins are immunoglobulins: IgG, IgM, IgA, complement C3, and complement C4 series. Among them, the clinical significance of detecting IgG, IgM, and IgA is to understand the body's anti-infection ability; and in immune complex diseases, detecting C3 and C4 can understand the degree of consumption.

2. Rheumatism and rheumatoid series

The items for detecting rheumatism and rheumatoid series in specific proteins are: anti-streptolysin (ASO), rheumatoid factor (RF), C-reactive protein (CRP), RF is an antibody against denatured IgG, common in rheumatism In the serum and synovial fluid of patients with arthritis, its quantitative determination is an important indicator for judging the patient's immune response and observing the efficacy. CRP has an auxiliary diagnostic effect on rheumatoid inflammation. ASO can be used for the differential diagnosis of rheumatic fever and rheumatoid arthritis.

3. Urine micro protein series

Specific proteins that belong to the urine microprotein series include: urine microprotein (MA), urine transferrin (TRU), urine immunoglobulin (IgU), α1-microglobulin (A1M), β2-microglobulin ( β2MG), in which glomerular proteinuria is due to an increase in the permeability of the glomerular filter membrane or (and) a decrease in the negative charge on the filter membrane. If urine protein excretion increases, but low-molecular-weight proteins, such as MA, TRU, etc., are called selective proteinuria; if high-molecular-weight protein excretion increases, such as IgU, etc., it is called non-selective proteinuria, and the latter indicates disease. serious.

Glomerular proteinuria can be seen in glomerulonephritis, diabetes, autoimmune diseases and tumors. Tubular proteinuria is caused by renal tubular reabsorption dysfunction, mainly due to increased excretion of small molecule proteins, such as β2MG and A1M. It can be seen in Shenmeng nephritis, potassium-losing nephropathy, renal vascular disease and heavy metal poisoning.

4. Acute inflammation protein series

C-reactive protein (CRP), α1-acid glycoprotein (AAG), haptoglobin (HPT), cerulocyanin (CER), α1-antitrypsin (AAT). During inflammation and tissue necrosis, certain plasma proteins will have characteristic changes, which are called acute inflammation phase reactions. CRP, AAG, HPT, CER and AAT are five acute inflammatory phase proteins, which can show increased levels in the early stages of acute injury. These indicators can reflect inflammation and infection earlier than traditional indicators such as fever, white blood cell elevation and abnormal classification, and accelerated erythrocyte sedimentation rate.

In addition, the duration of the increase in acute inflammation phase proteins is different, which helps to accurately judge the development process of inflammation. Among them, CRP is the most sensitive, and its content will increase within the first 2 hours of inflammation; HPT will increase significantly within 48 hours; AAG is an excellent indicator of disease recovery; and CER is often tested together with HPT and AAG to help Monitoring of acute inflammation phase response.

5. Nutritional status detection

The nutritional status of patients with albumin (ALB), prealbumin (PAB) and transferrin (TRF) can greatly affect the prognosis, efficacy and length of hospitalization. The nutritional status of patients can be evaluated by the ALB concentration, but due to its high content and long half-life (20 days), the sensitivity for nutritional status monitoring is low; but PAB (half-life is 2 days), TRF (half-life) It is 8 days), in the case of malnutrition, both can also show a rapid decline in content. At present, ALB, PAB, and TRF are commonly used in combination in clinical practice to evaluate nutritional status and monitor treatment effects to ensure that the results are more sensitive and accurate. In addition, PAB is synthesized in the liver, has a short half-life, and can be used as an indicator of early liver damage.

6. Nervous system disease detection

The immunoglobulins in cerebrospinal fluid (CSF): IgG, IgM, IgA, have important clinical value for the evaluation of the integrity of the blood-brain barrier and the diagnosis of inflammatory lesions in the spinal canal.

7. Blood disease detection

Common blood disease detection indicators in specific proteins are: transferrin (TRF), haptoglobin (HPT), ferritin (FER), antithrombin-Ⅲ (AT3), of which TRF can be used for iron deficiency anemia and Differential diagnosis of hemolytic anemia. Factors that affect iron metabolism or hematopoiesis can indirectly affect the level of transferrin. HPT can assist iron storage, and the decline in its level can be seen in severe intravascular hemolysis. FER is the most sensitive indicator to check iron deficiency in the body. Iron deficiency anemia, blood loss, and iron malabsorption caused by long-term diarrhea can lead to a decrease in FER. AT3 is a plasma protein that inhibits blood clotting and is an important indicator of the risk of thrombosis.

I believe that if you read the above knowledge carefully, you will become a half-medical expert. When you go to the hospital to get the test results, you can probably understand the increase or decrease of various specific protein values. What, in fact, any test is actually inseparable from the credit of in-vitro diagnostic reagents. When people go to the hospital or go for a physical examination, they basically have to deal with in vitro diagnostic reagents. It is the doctor’s eye to assist the doctor in diagnosing the condition, observing the efficacy and Adjusting the treatment plan and product quality is an important basis for ensuring correct laboratory results and diagnosis. As an excellent domestic in vitro diagnostic reagent raw material supplier, Desheng has a broad market demand and its development prospects are promising.