What blood tests will I need to find out if a patient and a potential donor are a kidney match?

 

There are three main blood tests that will determine if a patient and a potential donor are a kidney match. They are blood typing, tissue typing and cross-matching.

 

What is Blood typing (ABO compatibility)?
Blood typing is the first blood test that will determine if your blood is a compatible match with the potential donor's blood. This test measures blood antibodies that react with different blood groups.

If the donor's blood type works with your blood type, the donor will take the next blood test (tissue typing). The Rh factor (+ or -) of blood does not matter. The following blood types are compatible:

• Donors with blood type A… can donate to recipients with blood types A and AB
• Donors with blood type B… can donate to recipients with blood types B and AB
• Donors with blood type AB… can donate to recipients with blood type AB only
• Donors with blood type O… can donate to recipients with blood types A, B, AB and O (O is the universal donor: donors with O blood are compatible with any other blood type)

So,

• Recipients with blood type O… can receive a kidney from blood type O only
• Recipients with blood type A… can receive a kidney from blood types A and O
• Recipients with blood type B… can receive a kidney from blood types B and O
• Recipients with blood type AB… can receive a kidney from blood types A, B, AB and O (AB is the universal recipient: recipients with AB blood are compatible with any other blood type)

If blood types are not compatible, the donor still may be able to donate directly to you using treatments that lower your blood antibody levels. In addition, the donor may consider donating through a paired exchange program which would allow you to get a kidney from another donor who is not a match for their intended recipient. Talk with your transplant coordinator for more information and additional support.

 

What is Tissue Typing?
The first blood test is to determine the tissue (HLA) type of the patient and the potential donor to see how well they match. Each person's tissues, except for identical twins, are usually different from everyone else's. It is believed that the better the HLA match, the more successful the transplant will be over a longer period of time. Because of the way chromosomes/DNA are inherited or passed down in a family, a parent and child would have at least a 50 percent chance of matching, siblings could have a zero to 100 percent match, and unrelated donors would be less likely to match at all. The best match for the recipient is to have 12 out of s12antigen match. (This is known as a zero mismatch.) It is possible for all 12 markers to match, even with an unrelated deceased donor organ, if the patient has a very common HLA type.

 

The second blood test measures antibodies to HLA; this test is done for the patient only and is repeated frequently (sometimes monthly but less often dependent upon the transplant program policy). HLA antibodies can be harmful to the transplanted organ and they can increase or decrease over time so they must be measured while waiting for a transplant, immediately before a transplant surgery, and sometimes following transplantation. If a patient has HLA antibodies in their blood, they are considered HLA “sensitized” and it is best to find a donor with HLA types that avoid the HLA antibodies in the patient’s blood. Importantly, HLA antibody levels can change following events such as blood transfusions, miscarriages, minor surgeries (including dental work or fistula replacement) or severe infections and so these events should be told to the nurse coordinator.

 

What is Percent Reactive Antibody (PRA)?
This is another term you will hear often while being evaluated for a transplant. When you are exposed to foreign tissues, either through a blood transfusion, pregnancy or previous transplant, you may develop an antibody to different HLA proteins. If you test positive for HLA antibodies, you are considered “sensitized” and your PRA percentage will be greater than 0. The more HLA antibodies that you have in your blood, the higher the PRA percentage. It is important to test for the presence of these HLA antibodies before your transplant. If you have a high level of HLA antibodies, it may be more difficult to find a compatible kidney for you. However, new procedures such as plasmapheresis may be able to reduce the antibodies in your blood. As mentioned above, HLA antibodies can vary over time and so your %PRA can also change.

 

What is a Serum Crossmatch?
A serum crossmatch is a blood test you and the donor will have multiple times, including right before the transplant surgery. To do the test, cells from the donor are mixed with your serum. If your serum has antibodies against the donor's cells, the antibodies will bind the donor cells and be detected using a fluorescent detection method. If these antibodies are at high levels, the donor cells will be destroyed. This is called a positive crossmatch and it means that the transplant cannot take place. To do so would result in immediate rejection of the transplanted kidney.

D-Dimer Test

What is a D-dimer test?

A D-dimer test looks for D-dimer in blood. D-dimer is a protein fragment (small piece) that's made when a blood clot dissolves in your body.

Blood clotting is an important process that prevents you from losing too much blood when you are injured. Normally, your body will dissolve the clot once your injury has healed. With a blood clotting disorder, clots can form when you don't have an obvious injury or don't dissolve when they should. These conditions can be very serious and even life-threatening. A D-dimer test can show if you have one of these conditions.

Other names: fragment D-dimer, fibrin degradation fragment

What is it used for?

A D-dimer test is used to find out if you have a blood clotting disorder. These disorders include:

·         Deep vein thrombosis (DVT), a blood clot that's deep inside a vein. These clots usually affect the lower legs, but they can also happen in other parts of the body.

·         Pulmonary embolism (PE), a blockage in an artery in the lungs. It usually happens when a blood clot in another part of the body breaks loose and travels to the lungs. DVT clots are a common cause of PE.

·         Disseminated intravascular coagulation (DIC), a condition that causes too many blood clots to form. They can form throughout the body, causing organ damage and other serious complications. DIC may be caused by traumatic injuries or certain types of infections or cancer.

·         Stroke, a blockage in the blood supply to the brain.

Why do I need a D-dimer test?

You may need this test if you have symptoms of a blood clotting disorder, such as deep vein thrombosis (DVT) or a pulmonary embolism (PE).

Symptoms of DVT include:

·         Leg pain or tenderness

·         Leg swelling

·         Redness or red streaks on the legs

Symptoms of PE include:

·         Trouble breathing

·         Cough

·         Chest pain

·         Rapid heartbeat

This test is often done in an emergency room or other health care setting. If you have DVT symptoms and are not in a health care setting, call your health care provider. If you have symptoms of PE, call 911 or seek immediate medical attention.

What happens during a D-dimer test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a D-dimer test.

Are there any risks to a D-dimer test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

If your results show low or normal D-dimer levels in the blood, it means you probably don't have a clotting disorder.

If your results show higher than normal levels of D-dimer, it may mean you have a clotting disorder. But it cannot show where the clot is located or what type of clotting disorder you have. Also, high D-dimer levels are not always caused by clotting problems. Other conditions that can cause high D-dimer levels include pregnancy, heart disease, and recent surgery. If your D-dimer results were not normal, your provider will probably order more tests to make a diagnosis.

If you have questions about your results, talk to your health care provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a D-dimer test?

If your D-dimer test results were not normal, your provider may order one or more imaging tests to find out if you have a clotting disorder. These include:

·         Doppler ultrasound, a test that uses sound waves to create images of your veins.

·         CT angiography. In this test, you are injected with a special dye that helps your blood vessels show up on a special type of x-ray machine.

·         Ventilation-perfusion (V/Q) scan. These are two tests that may be done separately or together. They both use small amounts of radioactive substances to help a scanning machine see how well air and blood move through your lungs.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Formation of triglyceride in body

Triglycerides are the most common type of fat digested in the body and can be either consumed in the diet or produced in the body. They normally circulate in the bloodstream to supply energy to cells and are stored in body fat as an emergency store of energy.

If there are excessive levels of triglycerides in the body, the level of triglycerides circulating in the bloodstream and stored in body fat elevates and obesity becomes more common. This is also known as hypertriglyceridemia and is linked to an increased risk of other health conditions such as cardiovascular disease.

Chemical Composition

A triglyceride is formed when the three hydroxyls (OH-) groups of a single glycerol molecule react with the carboxyl group (COOH-) of three fatty acids by forming ester bonds.

The three fatty acids included in the triglyceride structure may or may not be the same in different triglycerides, such that there are many possible variations. The length of the fatty acid chains occurring in triglycerides can vary but are most commonly 16, 18, and 20 carbons.

What are triglycerides?

Triglycerides are fats from the food we eat that are carried in the blood. Most of the fats we eat, including butter, margarines, and oils, are in triglyceride form. Excess calories, alcohol or sugar in the body turn into triglycerides and are stored in fat cells throughout the body.

Triglycerides and cholesterol are both fatty substances known as lipids. But, triglycerides are fats; cholesterol is not. Cholesterol is a waxy, odorless substance made by the liver that is an essential part of cell walls and nerves.

Cholesterol also plays an important role in body functions such as digestion and hormone production. In addition to being produced by the body, cholesterol comes from animal foods that we eat.

Pure cholesterol cannot mix with or dissolve in the blood. Therefore, the liver packages cholesterol with triglycerides and proteins in carriers called lipoproteins. The lipoproteins move this fatty mixture to areas throughout the body. An elevated triglyceride level increases the risk of heart disease.

When are triglyceride levels measured?

Triglyceride levels are usually measured whenever you have a blood test called a Lipid Profile. Everyone over age 20 should have their cholesterol checked at least every 5 years. Your healthcare provider can check your cholesterol and triglyceride levels by taking a sample of blood, which is sent to a lab for testing. The Lipid Profile shows your triglyceride level, total cholesterol level, HDL cholesterol (high-density lipoprotein or “good” cholesterol) and LDL (low-density lipoprotein or “bad” cholesterol) levels.

Blood triglyceride levels are normally high after you eat. Therefore, you should wait 12 hours after eating or drinking before you have your triglyceride levels tested. Many other factors affect blood triglyceride levels, including alcohol, diet, menstrual cycle, time of day and recent exercise.

What are the guidelines for triglyceride levels?

The national guidelines for fasting triglyceride levels in healthy adults are:

• Normal: Under 150 mg/dl
• Borderline High: 151–200 mg/dl
• High: 201–499 mg/dl
• Very High: 500 mg/dl or higher

Levels higher than 200 mg/dL are associated with an increase in the risk of heart attack, stroke, and death.

How can triglyceride levels be lowered?

The first steps in treatment to lower triglyceride levels include eating a healthy diet, achieving and maintaining a healthy weight, and aerobic exercise on a regular basis.

To lower your triglyceride levels, your diet should be:

• low in fats
• low in sugars
• low in simple carbohydrates (the white stuff….potatoes, pasta, bread)
• low in alcohol

If you have high triglycerides and low HDL or high LDL levels, you may need to take medication along with making lifestyle changes. If your triglyceride levels are in the very high range (over 500 mg/dL) you are at risk to develop other medical problems, so you will most likely need to take medication.

 How do foods affect triglyceride levels?

Eating foods high in simple sugars significantly contributes to high triglyceride levels. Follow these guidelines to limit simple sugars in your diet:

• Substitute beverages like colas, fruit drinks, iced tea, lemonade, Hi-C and Kool-Aid with artificially sweetened beverages labeled “sugar-free” or “diet.”
• Limit hard candies, chocolates, candy bars, and gummy bears.
• Avoid adding table sugar and brown sugar to cereal, drinks or foods. Instead, use an artificial or herbal sweetener or nothing at all!
• Choose sugar-free gum or mints instead of the regular versions.
• Try light or low-sugar syrups on pancakes and waffles.
• Spread breads and crackers with no-sugar-added jelly or preserves.
• Snack on whole fruit instead of fruit roll-ups and other fruit-flavored treats.
• When selecting cereals, choose those with no more than 8 grams of sugar per serving.
• Try sugar-free gelatin, popsicles, yogurts, and puddings instead of the regular versions.
• Be aware that desserts labeled “fat-free” usually contain more sugar than the full-fat varieties and the same number of calories.
• Cut back on or avoid eating sweets and dessert foods, including cookies, cakes, pastries, pies, ice cream, frozen yogurt, sherbet, gelato, and flavored ices. All of these foods contain high levels of sugar.
• Read the ingredients list on food labels, and limit foods that list any of the following words (all simple sugars) in the first few ingredients:
• Sucrose
• Glucose
• Fructose
• Corn syrup
• Maltose
• Honey
• Molasses
• High-fructose corn syrup

Follow these guidelines to help limit natural sugars:

• Use honey and molasses sparingly; they are both high in sugar.
• Choose light yogurt (made with artificial sweeteners) instead of regular yogurt.
• Choose whole fruit instead of fruit juice.
• Limit dried fruits to ¼ cup per day. Dried fruits contain a more concentrated source of sugar than fresh fruits.
• Choose canned fruit in its own juice and strain before eating. Avoid canned fruits packed in heavy syrup.
• Limit your portion sizes of starchy vegetables to ½ cup. These include mashed potatoes, yams, beans, corn, and peas. Limit baked potatoes (with skin) to about 3 ounces.

Limit refined grains: products made with bleached, enriched or refined flour which contain very little or no dietary fiber.

• Choose breads, crackers, and cereals that contain whole grain oats, barley, corn, rice or wheat as the first ingredient
• Try whole-wheat pasta or brown rice.
• Choose breads, crackers, rice, and pasta with 2 or more grams of dietary fiber per serving.
• Select hot and cold cereals with 5 or more grams of dietary fiber per serving.
• Use barley, bulgur, couscous, millet or wheat berries as a side dish.
• Try whole wheat crackers with soup instead of saltines.

Alcoholic beverages can significantly raise triglyceride levels. Beer, wine, spirits, mixed drinks, wine coolers and coffee drinks containing alcohol are all examples. Men should not have more than 2 drinks per day. Women should have no more than one drink per day.

More ways to help lower triglycerides:

• Lose weight if you are overweight. Reduce the number of calories you eat each day by controlling portion sizes.
• Eat small, frequent meals and do not skip meals.
• Avoid late-night snacking.
• Participate in regular physical activity.

Omega-3 Fatty Acids

Foods that contain Omega-3 fatty acids have been found to be very powerful in lowering triglycerides.

To get more omega-3 fats in your diet, choose fatty fish for two or more meals each week. Examples of fatty fish are mackerel, salmon, sardines, tuna, herring, and trout. You can also choose plant-based forms of omega-3, such as soy foods, canola oil, flax seeds, and walnuts

Medication Therapy

Diet and exercise are not always enough to lower high triglyceride levels. If this is the case, you may need to take medication.

Statins are the first-line medications for patients with high triglycerides. While these medications are known for their cholesterol-lowering properties, they also work quite well at lowering triglyceride levels. They are also known to reduce the risk of heart attack, stroke and other major cardiac events.

You may need to take more than one medication. There are several second-line medications your doctor may prescribe. One is omega-3 fatty acids. Your doctor may recommend taking between 2,000 mg (2 grams) and 4,000 mg (4 grams) of DHA + EPA (the key omega-3 fatty acids) each day. In large trials, omega-3 fatty acid supplements have been shown to reduce cardiac risks. 1, 2

Niacin is also used to help lower triglyceride levels. When niacin is taken in large amounts, it acts like a drug. It is used to lower levels of both triglycerides and LDL (bad) cholesterol. Niacin therapy can also raise HDL (good) cholesterol levels. Studies show that niacin alone helps reduce the risk of heart attack, stroke, and death. However, we still do not have trial data showing that adding niacin to treatment with statins has a greater impact on the risk of heart attack, stroke, and death. There is some evidence that the combination does offer greater benefits than niacin alone.3 Our physicians at Cleveland Clinic often prescribe niacin in combination with statins to help reduce triglyceride and more importantly, help to lower LDL levels to reach lipid goals.

Researchers in a recent trial known as ACCORD studied patients with diabetes who were taking a statin and a medication called fenofibric acid (also known as TriCor and Trilipix) to lower triglyceride levels. Although the patients’ triglyceride levels went down, the study did not establish an overall benefit for those taking the medication. This was especially true among the women in the trial. The medication did seem to decrease the risk of cardiovascular events among a subset of men, particularly those with triglyceride levels higher than 220 mg/dL and very low HDL levels. Therefore, the medication may benefit men with high triglyceride and low HDL levels.4

These studies clearly show that the way in which a person lowers triglyceride levels makes a difference, and simply lowering the levels is not always enough to reduce the risk of cardiac events. Instead, an overall effort to reduce the risks of cardiovascular events is best.