Medicine News

AFP blood test. What does it mean for men, women during pregnancy, how to pass, the rate that shows

click fraud protection

Being pregnant women pass the blood tests for various indicators. These mandatory part and test AFP. In addition, his rent and liver diseases as well as in some other cases.

The content of the article:

  • 1 What does a blood test AFP?
  • 2 Indicators assessed using analysis of AFP
  • 3 Indications for study
  • 4 norm
    • 4.1 Men and women
    • 4.2 children
    • 4.3 In women during pregnancy
  • 5 Survey Preparation
  • 6 How to take a blood test?
  • 7 Elevated AFP. As indicated?
  • 8 The reasons for low levels
  • 9 How to normalize the level indicator
  • 10 Videos about the AFP blood test

What does a blood test AFP?

Abbreviation AFP stands for alpha-fetoprotein. It is a specific protein belonging to the glycoprotein, which is produced in certain organs of the fetus and is contained in large amounts in his serum.

In the adult age of the blood revealed only remnants of alpha-fetoprotein, as it is replaced by another similar in the structure of matter - albumin.

In the body of the embryo AFP has the following functions:

  • preservation and normalization of oncotic pressure in the blood plasma;
  • insta story viewer
  • creation of protection of the fetus from the mother's immune system attacks;
  • suppression of their own fetus immunity to his body did not begin to produce antigens to novel proteins that appear in the body of the child for the first time;
  • binding of estrogen mother;
  • binding and movement of nutrients and products of the endocrine system in the places of the body where they are needed. This is especially important for the polyunsaturated fatty acids that are not synthesized by the body and are delivered only from the external environment with food of plant origin, so their distribution and delivery is very important is the role of the carrier proteins.AFP blood test for men, women during pregnancy, how to pass, the rate that shows

Development of the AFP from the moment of conception, and it is in the first of the corpus luteumBut at the age of 5 weeks, the liver and the gastrointestinal tract of the embryo starts independent production of this protein.

Speaking generally, the embryo and the rate of AFP for the expectant mother is an indicator of a healthy or impaired child development, and all the rest - one of the most studied and demonstration cancer markers tumors.

Indicators assessed using analysis of AFP

AFP blood test which is taken from the woman during pregnancy, helps to assess the following indicators:

  • the likelihood of a child disorders, for example, the formation of the neural tube abnormalities associated with her cleft, such as anencephaly, or incomplete closure of the spinal column around the spinal bones brain;
  • risks of chromosomal abnormalities in the child (trisomy 13, 18, 21 chromosome);
  • possible obstetric pathology mother.

Separately from other studies in the blood levels of AFP are not significant in terms of diagnosis. However, if it deviates from the normal level, it is necessary to conduct a more in-depth survey to confirm or deny the alleged pathology.

Before talking about the deviation from the norm AFP index should be very accurately determine the gestation period, as this is the most important factor in the interpretation of test results.

For adult patients, both men and nonpregnant women, the rate of AFP is used to detect the following diseases:

  • malignant tumor in the breast in women;
  • malignancy in the liver;
  • Malignant pancreatic tumors;
  • teratoblastoma testes in men;
  • poorly differentiated cancer of any other body;
  • the presence of metastasis with different localization;
  • chronic hepatitis.AFP blood test for men, women during pregnancy, how to pass, the rate that shows

If AFP levels higher than normal, it does not indicate the presence of cancer with a probability of 100%But it requires further additional examination for the purpose of accurate diagnosis.

In addition, even though the diagnosis of "cancer" has been made, for the amount of AFP in the blood can not be determined any stage disease or tumor grade, respectively, for the definition of these indicators and other relevant survey.

In the treatment of cancer tumors it is advisable to control the content of AFP 1 once a month to assess to choose the right treatment and the positive effect of it, and, if necessary, promptly adjust.

Indications for study

AFP blood test is given to all women at gestational age of 14-20 weeks (optimal - 16-18 weeks). It, together with the analysis for hCG and free estriol, included in the binding screening for disorders in the formation of the embryo body.

Unscheduled blood sampling for the control of the AFP level is made, if the ultrasound showed the possible anomalies of formation:

  • neural tube;
  • front peritoneum;
  • urinary tract.

Particular attention to the amount of AFP in the mother's future appears, if the following risk factors are present:

  • akin to incest with the conception of the child;
  • genetic diseases the child's parents or relatives;
  • the presence of genetic abnormalities in previously children born in pairs;
  • maternal age of 35 years, provided that she gives birth for the first time;
  • the impact of x-ray radiation or toxic substances ingested or influence from the outside, in the early period of gestation.AFP blood test for men, women during pregnancy, how to pass, the rate that shows

In certain types of malignancies informative AFP levels at various stages, from diagnosis to diagnosis of relapses, so Oncology AFP is controlled in these cases:

  • If the patient is at risk for hepatocellular cancer because of the presence he has hepatitis, liver cirrhosis or abuse of alcoholic beverages. Such people should be a screening test for AFP 1 every 6 months, as the likelihood of their cancer liver disease 100 exceeds that of the average for the population.
  • If by results of US any tumor was found in the liver. Blood test for AFP in this case is conducted to confirm or refute the malignant nature of tumors.
  • Observation of the course of diseases such as hepatocellular carcinoma, testicular teratoblastoma, evaluation improvement or progression of a tumor, which helps to determine the most effective method to influence the it.
  • Controlling the amount of AFP occurs after the patient is in remission for early detection of recurrence or previously undetected micrometastases.

norm

The normal concentration of AFP is determined by gestational age, and after the baby is born - in accordance with their age and gender. Alpha-fetoprotein is in the circulatory system of the embryo from the moment of conception.

Its number reaches its peak for a period of 12-14 weeks, and then gradually decreases. Newborn content of AFP in the blood is still significantly (where the norm is more for girls than for boys), but by the time the child turns 1 year, it is set in an amount identical with that of an adult, and persists throughout life.AFP blood test for men, women during pregnancy, how to pass, the rate that shows

In children older than one year and the adult content of AFP is residual. The exception is pregnant women: the protein enters their bloodstream from the embryo through the amniotic fluid, so a certain level of increase in AFP's considered normal.

Increasing the concentration of AFP in pregnancy begins a period of 10 weeks, and by 32-34 weeks this index reaches a maximum and then begins its gradual decrease. The amount of AFP acceptable in either of two kinds of units: ng / ml or IU / ml.

In order to transfer the results from one measurement system to another, use the equality:

  • ng / ml = 1.21 IU * / ml
  • IU / ml = 0.83 * ng / mL.

Sometimes normal levels of AFP are subject to correction due to differences in the methods used biochemical research, as well as the types and brands of used equipment.

Men and women

The content of AFP in the serum of adults of both sexes must be not more than 7.29 IU / ml or 8.82 ng / ml in the determination of the indicator by enzyme immunoassay.

When used for counting the result of certain models analyzers, in particular, Cobas 8000 and Roche Diagnostics, AFP rate is considered to be normal if it is less than 5.8 IU / ml or 7.02 ng / ml.

There are several factors that influence the amount of AFPs may vary, and it will not be considered a pathology:

  • Most irregularities in the functioning of the endocrine system;
  • use on an ongoing basis biotin, antibody drugs or any other agents affecting the immune system or the activity of liver enzymes;
    AFP blood test for men, women during pregnancy, how to pass, the rate that shows
    Biotin affects the accuracy of the blood test AFP
  • ethnicity and race of the patient. For black people is characterized by the greatest number of AFP, the Europeans - the average, and the representatives of the Mongoloid race - the lowest.

children

AFP rate is set separately only for children under the age of 1 year, in the future it is identical to normal human adults.

the following possible values ​​based on gender and age established for children under one year:

Age / sex Girl Boy
0-1 months. Not more than 15 740 IU / ml Not more than 13 600 IU / ml
1-12 months. Not more than 64.3 IU / ml Not more than 23.5 IU / ml

In women during pregnancy

In pregnant women, the rate of AFP concentration in the blood correlates with gestational age:

Gestational age in weeks Reference values, IU / ml
less than 12 less than 15
13 15-25
14 15-30
15 15-60
16 17-65
17 19-75
18 22-85
19 25-95
20 27-105
21 32-110
22 37-115
23 42-120
24 47-125
25 52-130
26 57-135
27 62-140
28 67-145
29 72-150
30 77-155
31-32 100-250
AFP blood test for men, women during pregnancy, how to pass, the rate that shows

If pregnancy is prolific, the rate is multiplied by the number of embryos.

AFP control after 33 weeks of pregnancy does not make sense, as this figure does not carry any information.

Survey Preparation

AFP blood test requires that the general recommendations on preparations for the study:

  • Donating fasting blood should be not less than 8 hours. starvation, during which only water can be drunk. On the day prior to blood sampling is not recommended to over-consumption of food.
  • The optimal time for blood collection - 8-11 hours. morning.
  • Taking certain medications may affect the results, so the pre-should inform your doctor about the medicines consumed on a regular basis. The doctor will make a decision: to stop taking the drug at the time or to be tested without interrupting the treatment.
  • You can not drink alcohol during the days before blood sampling, and smoking exclude one hour before analysis.
  • On the eve of the study is not recommended to be subjected to physical and mental stress.
  • Directly in front of the fence material you need to spend 15-20 minutes at rest.
  • To track the dynamics of the indicator should be analyzed in the same laboratory.
  • A child under the age of 5 years should drink 150-200 ml of water in small portions over 30 min. Prior to the blood collection procedure.

AFP blood test for pregnant women appointed during the period between 14 and 20 weeks, but it has the most informative on 14-15 week.

How to take a blood test?

For analysis requires 10 ml of venous blood. The material takes away a nurse from the wrists to the elbow. AFP blood test for men, women during pregnancy, how to pass, the rate that shows

When you receive each patient the nurse should wear a new pair of gloves and use a new disposable syringe. The puncture site is pretreated with alcohol.

The material for the study subsequently becomes blood serum, which is to determine the amount of it is exposed to AFP-linked immunosorbent assay.

Shelf life of not more than 24 hours at an ambient temperature of 2-250FROM.

Elevated AFP. As indicated?

Excess blood levels of AFP on the maximum permissible value to a certain gestational age, can testify to the following pathologies:

  • open neural tube defects formation, such as spina bifida and anencephaly;
  • fetal umbilical hernia;
  • no portion of the esophagus or trachea with compound fistulas, this diagnosis (atresia) has a very poor prognosis and is considered a severe malformation;
  • duodenal atresia is usually treated surgically immediately after birth, and then he could lead a normal life;
  • Meckel-Gruber syndrome, which is a set of anomalies comprising the presence of extra fingers and toes, occipital hernia, multiple cysts on both kidneys, fibrotic changes liver;AFP blood test for men, women during pregnancy, how to pass, the rate that shows
  • fetal liver cells dying due to viral intrauterine infection;
  • chromosomal anomaly called Shershevskii-Turner syndrome, the main features of which are short stature, the presence of excess skin folds around the neck, sexual immaturity;
  • cleft of the anterior abdominal wall;
  • hydrocephalus;
  • anoxia child in the womb;
  • forming defects placenta;
  • ostegenez imperfect;
  • oligohydramnios.

Elevated levels of AFP suggests the presence of the above mentioned pathologies, but does not indicate a diagnosis directly. To further diagnose the pregnant woman must undergo such examinations as amniocentesis and ultrasound.

If fetal pathology has not been confirmed, and the AFP level is still high, the chances of various complications in childbirth, such as premature delivery or fetal weight is too small. In addition, the sharp increase in the AFP in the blood of pregnant can be a harbinger of fetal death after 10-14 weeks.

A blood test in adult males and non-pregnant women and children older than 1 year, which showed excess levels of AFP suggests the presence of one of the following diagnoses:

  • Liver cancer: Additional screening for the disease (ultrasound, CT, MR, biopsy) are assigned when the indicator 15 ng / ml in patients at risk. The indicator in the blood AFP shows growth for 1-3 months before the appearance of clinical symptoms of cancer, which contributes to the early diagnosis and timely treatment. 90-95% of patients with hepatocellular carcinoma is observed increase in AFP above 200 IU / ml.AFP blood test for men, women during pregnancy, how to pass, the rate that shows
  • embryonal carcinoma (Teratoblastoma) localized in the testes and ovaries. According to the level of AFP and hCG in view of the tumor and the presence of metastasis can be seen on the forecasts for the patient.
  • Oncologic diseases of various organs, in which AFPs It shows a slight increase and is not sufficiently informative indicator. However, increasing the level of AFP to 500 IU / ml in combination with elevated CEA is an indication of the presence of liver metastases.

If, after the treatment of cancer AFP dropped and then re-raised, it indicates the presence of disease recurrence or metastatic lesions.

When it comes to germ cell tumors, the increase in the AFP level of 100% of the mean emergence relapse, so the appropriate treatment should be started without waiting for the clinical manifestations disease. In addition, if after surgery AFP rate is not reduced, the tumor was removed completely or not there are already metastases.

If the increase in the level of AFP is temporary and does not exceed 100 IU / ml, it can be assumed that the following diseases:

  • hepatitis or cirrhosis of the liver;
  • liver damage due to excessive alcohol consumption.

The reasons for low levels

About AFP reduced level in the blood can speak out on pregnant women.

Lack of this protein may indicate the possible development of the following pathologies:

  • Genetic disease: Down syndrome, Edwards, Patau;
  • intrauterine fetal death;
  • the likelihood of miscarriage;
  • a normal embryo is not formed due to defects in the egg, or fertilization immediately 2 sperm, resulting instead fetuses grow chorionic villi, taking the form of bubbles. This pathology is called molar pregnancy and can become malignant tumor metastasis;
  • growth retardation;
  • missed abortion.

Separately, AFP does not apply, as an indicator of child development disorders. In addition, when identified deviations AFP concentration in the blood of pregnant women from the norm, it is necessary to clarify once again gestation: it is crucial to assess the results of the analysis.AFP blood test for men, women during pregnancy, how to pass, the rate that shows

Insufficient content of AFP in the blood of pregnant women may be due to the presence of her obesity or diabetes.

For cancer patients a decline in blood levels of AFP is a favorable factor and indicates the correctness of the chosen treatment.

How to normalize the level indicator

Method of AFP concentration in the blood to normal depends on the cause of deviations.

If the pregnancy revealed violations of fetal development, causing an increase or decrease of AFP content, then using additional diagnostic methods evaluated the severity of defects and the decision to maintain or abortion.

In the case of malignant tumors the AFP level will decrease during the respective treatment if it take on a momentum proper effect. Especially illustrative AFP levels in the treatment of embryonic tumors. After removal of egg teratoblastomy AFP, together with hCG should be monitored every 7-10 days for several weeks.

In the case of the normalization of these indicators can say that the removal of the tumor was the first step, otherwise the event is likely to occur in the lymph nodes or metastasized to other organs, which requires additional treatment.

Thus, the AFP in the blood is an important indicator of successful pregnancy and the presence or absence cancer, but it is rarely a cause for diagnosis without the results of additional analyzes and surveys.

Interpretation of the results is done only to physicians, self-diagnosis and self-treatment is unacceptable.

Registration of the article: Mila Friedan

Videos about the AFP blood test

On prenatal screening - AFP, HCG, etc .:

  • Share
Contraceptives reduce the risk of ovarian cancer and increase the risk of breast cancer
Medicine News

Contraceptives reduce the risk of ovarian cancer and increase the risk of breast cancer

More recently, an unusual fact has been established. It turned out that regular use of contraceptives reduces the development of ovarian cancer...

Installation of brackets. Stages, types, costs, care after dental procedures
Medicine News

Installation of brackets. Stages, types, costs, care after dental procedures

In dentistry, braces are used to eliminate the problems of the oral cavity. Thanks to them, you can fix even complex pathology bite. Before install...

Lingual braces. Reviews what it is, the price of installation, system photos
Medicine News

Lingual braces. Reviews what it is, the price of installation, system photos

Lingual braces - a standard bracket system, which has been improved orthodontist for to remove metallic structure of the tooth surface, but still g...