Saturday, April 5, 2008

White cells in blood

One important component of the body’s defence system is the neutrophil, a type of white blood cell in the blood.

MY aunt, who has been on cancer chemotherapy, was recently admitted because of fever. She was told she has low white blood cell count. The doctor said this is neutropenia. What is neutropenia?

Neutropenia means an abnormally low number of neutrophils in your bloodstream. (Neutro for “neutrophils”, penia = low.)

A neutrophil is a particular type of white blood cell that specialises in fighting off infection.



Some drugs may lead to decreased levels
of neutrophils (a type of white blood cell)
in the blood. - Photos.com


What are white blood cells are how many types are there? I thought blood is of a red colour.

Your blood is red because of the haemoglobin in it. The cells in your blood are predominantly made of red blood cells, which carry oxygen, but there are a certain number of white blood cells (leukocytes) that must be present in your bloodstream. These are part of your body’s immune system.

The density of leukocytes in your bloodstream is 5,000 to 7,000 cells every square mm.

There are several types of white blood cells:

Neutrophils – these form 50% to 70% of all white blood cells. They literally “eat” bacteria in a process called phagocytosis, in which they surround the bacteria and take it into their own cellular material.

You can actually see them in wounds that have a lot of pus.

After ingesting a few bacteria, they die.

Eosinophils – these reddish cells specialise in phagocyting parasites. They form only 2% to 4% of white blood cells.

Basophils – these are the rarest of the white blood cells, present in only 0.5% to 1%. They secrete substances like anti-clotting factors and histamines. Their main function is in the hypersensitivity reaction.

Lymphocytes – these form 20% to 40% of the cells. They are also present in your spleen, lymph nodes, thymus, tonsils and other lymphoid tissues. They are the main aggressors of the immune system because they secrete antibodies that bind to viruses and bacteria to nullify them so the neutrophils can later ingest them easily.

Lymphocytes also have a “memory” of the bacteria and virus forever, so when the same bacteria or virus attacks you, the lymphocytes will be able to mount a rapid response.

This is called “being immune” to the disease.

Monocytes – these form 3% to 8%. They play a role in phaygocytosis as well as secreting interferons and other substances.

Neutrophils leave the blood stream after six to eight hours and enter the tissues, where they either stay in the cells or die.

Is neutropenia caused only by chemotherapy?

Neutropenia can exist in normal healthy populations. Certain black people and Yemenite Jews have it. But in most people, neutropenia is a bad sign.

Neutropenia can be caused by any disease that:

·Decreases the production of white blood cells by the bone marrow – these include drugs (for example, chemotherapy); diseases of the bone marrow (for example, leukaemia); infections which suppress the bone marrow (viral diseases, TB); vitamin deficiencies.

·Destroys the white blood cells quickly after they are produced and released – when antibodies attack the white blood cells (Felty’s Syndrome); certain drugs that stimulate antibodies to attack its own white blood cells.

·Causes the accumulation or pooling of white blood cells, which takes them out of the blood stream (with some overwhelming infections, during haemodialysis, during heart-lung bypass surgery.)

How low does your white blood cell count need to go to be classified as neutropenia?

The normal white blood cell count is 4,500 to 10,000 white blood cells per microlitre. Neutrophils will form 50% to 70% of that. When your absolute neutrophil count (ANC) is 1,000 to 1,500 cells per mm3, it is mild neutropenia.

When your ANC is 500 to 1,000 cells per mm3, it is classified as moderate neutropenia. When your ANC is less than 500 cells per mm3, it is severe neutropenia.

What happens if you have neutropenia?

Because neutrophils are needed for your immune system and body defence, if you have neutropenia, then you can have infections.

The most common site for infections due to neutropenia begin with your mucous membranes, such as your lips, mouth, and eyes. The second most common infection site is your skin. This presents as ulcers, abscesses, rashes and delay in wound healing.

You have to be especially vigilant to look out for these if you have neutropenia because the normal signs of infection like warmth and swelling may not be present. This is because neutrophils are needed to mount a normal response, and if you have neutropenia, you will not have a normal response.

Note that people with neutropenia are not at increased risk for viral or parasitic infections because these are taken care of by the lymphocytes and eosinophils.

Serious infections can result in fever. This condition is then called febrile neutropenia. This is a potentially dangerous condition that can result in widespread infection.

There are drugs called the granulocyte-colony-stimulating factors to help boost your neutrophil count.

# Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health advice, computers and entertainment. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.

Are your kidneys okay?

Studies in the US suggest that about 10% of adults have some form of kidney damage ... and do not know about it. Take a screening test to find out if you’re one of them.

YOU might have heard stories about people whose kidneys failed suddenly. In reality, their kidneys had been damaged for some time, but they just weren’t aware of it. They had chronic kidney disease (CKD), which often presents no signs in the initial (“silent”) phase, sometimes lasting for years!

However, a time will come when the disease will start to manifest symptoms. By then, the person’s condition is already serious. Irreparable damage has been done. Most of the tiny filters (called nephrons) in the kidneys have been damaged and there are just too few left to take on the extra load of filtering the blood.

Without treatment, all the nephrons will eventually be destroyed and end-stage kidney failure will result.

Aris bin Said, 53, is a dialysis patient at NKF. For years, he didn’t know he had high blood pressure and diabetes. It didn’t really bother him until, one day, both his kidneys failed.

Causes of CKD

“The kidneys are fragile and have to be protected,” says Dr Thiruventhiran Thilaganathan, consultant nephrologist and Hon Secretary on the Board of Managers, National Kidney Foundation (NKF).

He explains: “CKD can result from certain kidney diseases (for example, polycystic kidney disease), kidney infections, blockage of the renal artery (that supplies blood to the kidney), blockage in the urinary tract (due to kidney stones or tumours), long-term use of certain medicines, and inborn kidney deformities or disorders.

“The top three causes of CKD in Malaysia, however, are uncontrolled diabetes (57% of CKD cases), unknown causes (27%) and uncontrolled high blood pressure (6%).”

Diabetes is a disease characterised by constantly high concentrations of glucose in the blood. Prolonged exposure to such high glucose levels will damage the kidneys and cause a condition called diabetic nephropathy, which is the No 1 cause of kidney failure. Almost a third of people with diabetes develop diabetic nephropathy.

High blood pressure (or hypertension) refers to how hard the blood pushes against the walls of your arteries. Chronic high blood pressure can damage the blood vessels and filters in the kidney. This is especially bad news for people with diabetes because up to 60% of them will eventually develop high blood pressure.

Signs of advanced chronic kidney disease

  • Abnormally frequent and voluminous urination (especially at night), which, over time, reverses to become less frequent and in smaller amounts.
  • Water retention causing swollen legs, ankles or feet, and puffy eyes.
  • Continual itch anywhere on the body for no apparent reason.
  • Foamy urine (due to the presence of protein).
  • Easily tired and always sleepy.
  • Frequent headaches.
  • Trouble sleeping.
  • Poor appetite, accompanied by weight loss.
  • Frequent feeling of wanting to vomit.
  • Blood in the urine.

Time to get tested!

Dr Goh Bak Leong, consultant nephrologist and member of the NKF Board of Managers states that, in Malaysia, diabetes is estimated to affect 14% of adults while the prevalence of high blood pressure stands at a staggering 42.6% for adults 30 years and above.

He remarks: “Both diabetes and hypertension can be without symptoms; so many Malaysians out there are walking around totally unaware that their blood glucose or blood pressure may be abnormally high.

“It is also highly likely that they don’t know that they either already have CKD or are seriously at risk of developing it.”

Dr Tan Chwee Choon, 2nd Vice-Chairman of the NKF Board of Managers, adds: “Clearly, kidney damage has to be detected as early as possible. The sooner you know you’re in trouble, the sooner you can be treated to prevent further deterioration,” he says.

“You have to make the effort to care for your kidneys and prevent end-stage kidney failure. Taking a morning or afternoon off to see the doctor for a test is a small inconvenience compared with spending the rest of your life on dialysis,” he remarks.

Evidently, NKF is serious about making the public aware of their CKD risk. As it is, the NKF LifeCheck Mobile Health Screening Unit has already screened more than 4,000 people in Klang Valley since its launch in January 2008.

Dr S.S. Gill, Chairman of NKF Board of Managers, elaborates: “NKF LifeCheck is part of our Kidney Care community education programme. Our NKF LifeCheck bus visits companies and communities daily to offer tests to detect protein in the urine (one of the first signs of kidney damage), high blood glucose, high blood pressure and high blood cholesterol. Checks are also performed to measure body weight status.

“Participants are then counselled, based on their results, by qualified personnel. People with suspected kidney damage, diabetes or high blood pressure will be advised to visit their doctors for a more thorough diagnosis.

“The tests and counselling cost only RM2 per person. This practically-free service is made possible by the generosity of the Sunway Group and other companies who care enough about the community to underwrite the actual, much higher cost of NKF LifeCheck.”

CKD is a serious disease that is made worse by the ignorance and complacency of people. World Kidney Day 2008 has just passed, but hears the echo of its call: “Are your kidneys OK?” If you don’t know the answer, ask your doctor today.

Healthy values for healthy kidneys

  • Blood glucose – Less than 5.6 mmol/L (fasting)
  • Blood pressure – Less than 130/90 mm/Hg
  • Urine tests – No trace of protein; no trace of glucose; no trace of blood
  • Waist circumference – Less than 102 cm (men); less than 88 cm (women)
  • Body mass index – Between 18.5 and 24.9 kg/m2

This article is courtesy of NKF KIDNEY CARE, a community education programme by National Kidney Foundation of Malaysia. NKF provides subsidised dialysis treatments and free medications, laboratory tests, follow-ups and welfare assistance to NKF patients besides ongoing public education initiatives.

NKF welcomes public donations to support its work. For more details, please contact NKF Hotline: 1300-88-3110; website: www.nkf.org.my.