Chronic kidney disease of uncertain aetiology (CKDu) of Sri Lanka : War on kidney

Dr Tilak Abeysekara
 (MBBS, MD, MRCP)
Consultant Nephrologist Centre for Education,
Research and Training on Kidney Diseases (CERTKiD)
Faculty of Medicine University of Peradeniya

Kidney is a bean shaped organ which is involved in vital function of the human body. Typical length of the kidney of a healthy adult varies from 10 - 14 cm and width varies from 3 - 4 cm while it weights between 120 - 175 g.

Kidneys are located just below the diaphragm in the abdominal cavity, on each side of the spine, in between12th thoracic and third Lumbar vertebra. Normally right kidney is located slightly lower than the left. There are about one million nephrons in a kidney which carry out several functions.

Following are the most important among the many functions in which kidney performs.

•  Excretion of waste products including ammonia and urea.
•  Regulation of ions such as sodium and potassium and acid-base homeostasis.
•  Secretion of erythropoietin which is important for red blood cell production - Production of active Vitamin D.
•  Blood pressure regulation Chronic Kidney Disease (CKD)

Chronic Kidney Disease is a loss of kidney function over a period, due to a long-term disease or other reasons. There are several causative factors of Chronic Kidney Disease including

• Uncontrolled diabetes
• Uncontrolled high blood pressure
• Kidney stones
• Infections
• Endemic kidney disease
• Use of medicines without prescriptions

History and geographical distribution of CKDu

During the year 1990-1992, there were numbers of people suffering from CKD and number of deaths due to CKD in Padhaviya, Anuradhapura District. Later, more people have been recorded from nearby regions including Medawachchiya, Medhirigiriya in Polonnaruwa District, Girandurukotte and Mahiyanganaya in Uva Province, Dehiattakandiya in Eastern Province and Wilgamuwa, Hettipola in Central Province.

Aetiology of the disease is not the above-mentioned diabetes mellitus and high blood pressure etc, so the aetiology is uncertain to the date, hence the disease is known as chronic Kidney Disease of Uncertain aetiology.

Symptoms of CKDu

CKDu is common among adults and no paediatric cases are recorded. Mostly, symptoms appear at the end stage of the renal damage. To identify the disease at early stages, there is a need of urine test, blood test and ultra sound scanning of kidneys. However, some patients have symptoms like;

•  Feeling unwell
• Pain in the flank of abdomen
• Backache
• Dysuria

Majority of the patients are male farmers. Sometimes several members of the same family are affected, so it is suspected that there is a genetic effect on the disease.

If the patient is in the later stages of CKDu, they will experience,

• Loss of appetite and vomit feeling
• Itching
• Fatigue
• Anemia
• Oedema
• Hypertension
• Backpain
• Depression

Diagnosis

It is important to subject patients for several urine and blood tests via screen programmes in endemic areas. Following two tests are important.

Urine tests

1. Urine albumin

2. Urine full report

3. Albumin (or protein) Creatinine ratio

Blood tests

1. Serum creatinine - to calculate glomerular filtration rate (estimated) – eGFR

2. Creatinine clearance

3. Serum lipids

4. Calcium

5. Phosphorous

6. Full blood report

7. Serum total protein

8. Serum electrolytes (sodium, potassium and bicarbonate)

Kidney function is being impaired with the progressive damage to the kidney. Status of CKDu has been categorized in to five stages according the kidney function.

Table 1: CKD staging

Stage GFR (ml/min/1.73m2)

1 >90

2 61-90

3 31-60

4 16-30

5 0-15

Confirmation of the disease is done using a kidney biopsy. This is available only in certain hospitals with a referral from a consultant nephrologist. So, there is no need of being afraid to such procedures.

Screening programmes for CKDu

If the patient has been identified at early stages, the disease progression can be stopped or slow down. Therefore, the people who are above 16 years of age from CKDu endemic region, should participate to screening programmes to check whether they have the disease. In these programmes, urine protein and serum creatinine will be tested and if you found to be a CKDu patient after an ultrasound scan, you will be directed to the nearby renal clinic.

Causes of the disease

Although several local and foreign universities carry out various research, the exact cause (or causes) of the disease is yet uncertain. Several research findings have shown that the disease is strongly correlated with water. However, the most probable causes are;

1. Fluoride concentration and

hardness (due to Ca and Mg)

2. Agrochemicals

3. Heavy metals (Cd, As etc.)

4. Cyanobacteria toxins

5. Genetic factor

6. Ochratoxins

7. Aristalochic acid

8. Long term exposure to sunlight and dehydration 

Prevention and the treatments for CKDu

It is important to focus on following facts to prevent the disease.

1. Use of high quality drinking water

2. Use of protective gear while using agrochemicals and proper use agrochemicals.

3. Stopping smoking and drinking alcohol

4. Proper use of medicines or drugs

5. Life style modifications

6. Limiting the usage of aluminium utensils for cooking purposes

7. Regular daily exercises

8. Early diagnosis of the disease and regular treatments

Treatments those are intended for other chronic kidney diseases are currently used for CKDu;

• Refrain from taking high protein diets if the kidney function if impaired
• Special attention to control hypertension
• Treatment for anemia
• Treatment for bone diseases If the kidney function is completely lost (i.e. stage 5),
• Haemodialysis
• Peritoneal dialysis and
• Kidney Transplantation are the treatment options available.

Institutes and organisations for the prevention of CKDu

Local

•  Presidential task force on prevention of chronic kidney disease
• Ministry of health, nutrition and indigenous medicine
• Universities (Peradeniya, Rajarata, Colombo, and Kelaniya etc.)
• Provincial Ministries of Health
• Regional Ministries of Health
• Ministry of Social Services
• Divisional Secretariats
• National Water Supply and Drainage Board
• Department of Agriculture
• Mahaweli Authority
• Non-governmental organisations (NGOs)

Foreign

•  World Health Organisation (WHO)
• International Society of Nephrology
• Foreign universities (leading universi ties in Japan, Germany, USA, Singa pore and Australia)

Priorities of the National Plan on CKDu Prevention in Sri Lanka

1. Lifestyle development for disease prevention

2. Early diagnosis of the disease

3. Patient management

4. Welfare of patient, family and the society

5. Provision of good quality drinking water

6. Healthy food and nutrition

7. Establishment of database for CKDu patient management

8. Establishment of surveys, researches and policies for CKDu