Hepatitis C is a major problem in dialysis patients. Dialysis patients are at risk of seroconversion (getting infected with the virus) since their blood is being drawn out of the body and is passed through an external system. This risk is further increased when the dialyser is reprocessed.
Regular testing for the presence of the Hepatitis C virus is an important tool to prevent seroconversions in dialysis centres. To be able to control transmission of this virus, all patients of a dialysis centre must adhere to the testing protocols instituted by the centre.
There are multiple ways by which the presence of the Hepatitis C virus can be tested:
1. Liver Enzymes: During the early few days of transmission, the liver enzymes of the patient might be elevated. Liver enzymes include ALanine Transaminase (ALT) and ASpartate Transaminase (AST). These are also called Serum Glutamic Pyruvic Transaminase (SGPT) and Serum Glutamic Oxaloacetic Transaminase (SGOT) respectively. These tests are relatively cheaper than the other tests and so, some centres test this on a monthly basis to try and catch those transmissions that might have occurred during the past few days.
Note that the levels of these enzymes typically return to normal in due course. Also they could be elevated due to other conditions. That is why these tests can never be relied upon completely. They only serve as early indicators that something could be wrong. Further investigations is almost always necessary.
2. Hepatitis C Antibodies: Whenever the body gets infected with the Hepatitis C virus, it instinctively produces antibodies that try to fight and kill the virus. There is a blood test that tests for the presence of these Hepatitis C Antibodies that can also signal that there has been a Hepatitis C infection in the body. Again, this is also an indirect method of testing as this does not actually test for the virus itself. Rather, the test is for something that is produced in response to the virus.
One important thing to note about Hepatitis C Antibodies is that these antibodies take 4-6 weeks after the transmission to reach levels that can actually be detected. Sometimes, these antibodies may successfully eliminate the virus. In this case, no further treatment may actually be necessary. Evidently, this test is also not a completely reliable test to determine if a patient is a carrier of the virus or not.
3. HCV RNA PCR: This test actually tests for the genetic material that constitutes the Hepatitis C virus. This is the only direct test for Hepatitis C among the tests listed here. This actually tests for the virus itself and not any other surrogate. This test is of two types: Qualitative and Quantitative. The Qualitative test will only say if the virus is found or not. A Quantitative test will also tell you how many copies of the virus are present per millilitre of blood. This is the most accurate method among all those listed here.
If at any time, any of the earlier mentioned tests is reported as positive, it is imperative that the confirmation is obtained by testing for HCV RNA PCR. Only a positive HCV RNA PCR test can confirm if the patient is indeed a carrier of the virus. If the preceding two tests are both positive but the HCV RNA PCR is negative, it still means that the patient is negative for the virus.
Frequently Asked Questions:
1. If the HCV RNA PCR test is the only reliable test, why even bother testing the other two?
Cost. The HCV RNA PCR test is significantly more expensive that the ALT/AST or HCV Antibodies tests. That is why these are first tested and only if necessary, the HCV RNA PCR is tested. If cost is not a constraint, then by all means, the HCV RNA PCR should be tested.
2. If someone has a positive HCV Antibodies test, does it mean they are carriers of the virus?
Not necessarily. The following two reasons could also result in a positive HCV Antibodies test for patients not carrying the virus:
Early infection that was fought and eliminated by the body by itself
Patient was successfully treated for Hepatitis C
3. What is the recommended testing schedule for these tests?
Each dialysis centre has different protocols. At NephroPlus centres, the following protocol is followed:
ALT - every month
HCV Antibodies - every 3 months
HCV RNA PCR - if any of the above turn out positive
Further, at entry, both ALT and HCV Antibodies are tested. In some cases, depending on the past history and dialysis centres dialysed in in the past, HCV RNA PCR may be required on a case by case basis.
Hepatitis C Treatment:
A new class of drugs called Direct Acting Agents are now available with excellent success rates in treating Hepatitis C. If you are a carrier of the Hepatitis C virus, please talk to your nephrologist about getting treated with this class of drugs. Several studies have shown that outcomes and longevity of dialysis patients is improved after being successfully treated.
Hepatitis C is a major problem for dialysis patients. It is primarily transmitted through the blood and dialysis patients, by virtue of having their blood exposed practically every other day in the dialysis centre are at high risk of seroconversion. Regular testing as per dialysis centre protocols is an important weapon in preventing cross infections. Treatment with Direct Acting Agents must be considered for all dialysis patients who have been infected with the Hepatitis C virus.