Interpreting test results can be rather challenging for a non-medical individual. Here is a small breakdown of one of the parameters of a complete blood test:
The A/G Ratio
It is an abbreviation of albumin and globulin, which are types of proteins found in your body. The main function of these proteins is to maintain the plasma colloid osmotic pressure – that is a specific pressure in the blood that draws in water and keeps it at a fixed volume within the vessels. A basic review of biochemistry will also allow you to understand that these negatively charged proteins also keep the positively charged ions like Sodium at a fixed range within the blood; aiding their transport as well as buffering the pH of the blood. Maintaining this homeostatic range is crucial for effective body function.
Normal Range of A/G Ratio
The normal reference range of the a/g ratio is 1.5-2.5: 1. That is for 1 to 2 polypeptide chains of albumin there is one globulin protein in an average person. The total protein content is calculated by adding albumin and globulin content to the serum sample. This may vary from person to person. Consult your general physician if the ratio is lesser or greater than the given range. You may require some additional lab tests but you are not having any clinically relevant symptoms due to a deranged lab result, the doctor will counsel you that there is nothing to worry about. Danger signs include pedal edema or generalized edema known as anasarca, decreased urine output, chronic fatigue, chronic anorexia, and weight loss, severe burns, ongoing infection especially in liver or kidney disease, hemodilution as well as alcohol dependence.
Leading Causes of High High A/G Ratio
This means that the amount of albumin in the blood is greater than the globulins or that the overall protein content within the serum is increased. The normal albumin reference range in a blood test result is 3.5 to 5.5 gm/dL.
Higher levels of A/G ratios are rarely seen clinically, except in cases of chronic dehydration. Here, the amount of water in the serum is significantly reduced, thus causing a greater accumulation of solvents such as proteins in each plasma or serum sample. The colloid osmotic pressure may be subsequently increased.
Leading Causes of Low A/G Ratio
Overproduction of Globulins
An increase in the denominator, that is the globulins will cause a hike in the ratio. The normal globulin reference range is 2.5 to 3.5 gm/dL. This condition is seen in specific pathologies such as myeloma and some autoimmune diseases.
Underproduction of Albumin
This may be due to chronic malnutrition due to eating disorders, inadequate protein intake which may be associated with obesity as well as malnutrition. Or could be due to defective protein synthesis because of liver diseases, like cirrhosis, fatty liver disease as a result of prolonged alcohol consumption, or non-alcoholic fatty liver disease. Any chemical or physical insult to the liver lowers or adversely affects the protein synthesis, thus decreasing the required amount in the serum.
Selective Loss of Albumin from the Blood
Normally, protein is not filtered from the blood in the kidneys because of its size and negative charge. But in renal pathologies such as nephrotic syndrome, the defective lining of the glomerulus causes the filtration and excretion of protein. In this case, your blood test shall indicate hypoalbuminemia whereas a urinalysis will show the presence of albumins – which isn’t seen in a healthy person.
Redistribution of Proteins
This occurs in conditions such as vessel wall inflammation that causes the smaller-sized proteins such as albumin and globulin to leak out of the plasma. Hemodilution, in which there is excessive water retention may also present as hypoalbuminemia due to the increased water concentration and comparatively reduced albumins and globulins in the serum sample.
Thus, a lower ratio of A/G is clinically more alarming than an increased one. It makes other baseline investigations necessary especially kidney and liver function tests. The latter can be more extensive and invasive, thus the a/g ratio is used as a basic test to elicit necessary information. See a doctor if the a/g ratio is staggeringly lower than 1. You may be referred to a nephrologist or a gastroenterologist for a more comprehensive review.