Hepatitis B: Can It Cause Kidney Disease?

Learn why Hepatitis B could affect the kidney, and what can you do about it

Liver, illustration
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Medical circles widely accept that one of the most misleading disease nomenclatures out there is for Hepatitis B and Hepatitis C-related liver disease. The titles are somewhat insufficient to describe these diseases since the term "hepatitis" implies inflammation of the liver. This gives the impression that the only organ affected in Hepatitis B or C is the liver, which is misleading because both of these diseases see an involvement of organs other than the liver, and are therefore bona fide systemic (and not local) disease states.

The kidney is one such organ that hepatitis viruses affect both directly and indirectly. Hepatitis viruses are not the only infectious agents that can affect the kidney. However, their role in kidney disease is important to note given the relatively higher prevalence of these viral infections. Let's discuss some details regarding Hepatitis B virus related kidney disease.

How Common Is the Association of Kidney Disease With Hepatitis B?

Kidney disease due to Hepatitis B virus infection is seen far more frequently in people infected from the virus either during infancy or childhood. These patients are more likely to become "carriers" and carry a higher risk of kidney disease. 

Why Would a Liver Virus Damage the Kidney?

Even though its frequently assumed, damage to the kidney from Hepatitis B virus is not usually a result of direct infection. In fact, abnormal reaction of the immune system to certain parts of the virus could have a bigger role in disease causation.

These viral components will typically get attacked by your antibodies in an attempt to fight the infection. Once this happens, the antibodies will bind with the virus, and the resultant debris will get deposited in the kidney. This can then set off an inflammatory reaction which could cause kidney damage.

Hence, rather than the virus directly affecting the kidney, it is your body's response to it that determines the nature and extent of kidney injury.

Types of Kidney Disease Induced by Hepatitis B Virus Infections

Depending on how the kidney reacts to the virus and the inflammation cascade noted above, different kidney disease states can result. Here is a quick overview:

  1. Polyarteritis Nodosa (PAN): Let's break this name into smaller, digestible parts. The term "poly" implies multiple, and "arteritis" refers to inflammation of the arteries/blood vessels. The latter is often referred to as vasculitis as well. Since every organ in the body has blood vessels, (and the kidney has a rich vasculature), polyarteritis nodosa is a severe inflammation of the blood vessels (in this case, the kidneys' arteries) which affects the small and medium sized blood vessels of the organ.

    The appearance of PAN inflammation is very typical. This is one of the earlier kidney disease states that can be triggered by Hepatitis B infection. It tends to affect middle-aged and older adults. The affected patient will typically complain of nonspecific symptoms like weakness, fatigue, and joint pains. However, certain skin lesions can be noted as well. Test for the kidney function will show abnormalities but will not necessarily confirm the disease and a kidney biopsy will usually be necessary.
  1. Membranoproliferative Glomerulonephritis (MPGN): This mouthful-of-a-disease-term refers to excess of inflammatory cells and certain kinds of tissue (basement membrane in this case) in the kidney. Again, this is an inflammatory reaction rather than direct viral infection. If you have Hepatitis B virus infection and start to see blood in the urine, this is something that needs to be considered. Obviously, presence of blood in the urine will not be enough to confirm the diagnosis even if you have Hep B virus infection. Hence, further tests including a kidney biopsy would be necessary.
  2. Membranous Nephropathy: A change in a part of the kidney filter (called the glomerular basement membrane) leads to this. The affected patients will begin to spill out an abnormally high amount of protein in the urine. As a patient, it's hard to comment on proteins' presence in the urine unless it's extremely high (in which case you could expect to see foam or suds in the urine). Blood is a rarer finding in the urine in this case, but could be seen as well. Again, blood and urine tests for kidney function will show abnormalities but in order to confirm the disease, a kidney biopsy will still be required.
  3. HepatoRenal Syndrome: An extreme form of kidney disease because of preexisting liver disease is something called hepatorenal syndrome. However, that is not necessarily specific to Hepatitis B related liver disease, and can be seen in any kind of advanced liver disease states where the kidneys get affected because of multiple mechanisms.

How Do You Diagnose Hepatitis B Virus Associated Kidney Disease?

If you have hepatitis B virus infection, and are worried that your kidneys could be getting affected, you can get tested.

  1. Obviously, the first step is to make sure that you do have hepatitis B virus infection, for which there is a different battery of tests that don't necessarily need a kidney biopsy. If you come from an area that is known to have high rates of hepatitis B virus infection (endemic area), or have risk factors for hepatitis B virus infection (like sharing needles for IV drug abuse, have unprotected sex with multiple sexual partners, etc.), certain telltale blood tests that look for different "parts" of the hepatitis B virus should be able to confirm infection.

    Testing is also done for the antibodies that the body makes against the hepatitis B virus. Examples of these tests include HBsAg, anti-HBc, and anti-HBs. However, these tests might not always be able to differentiate between active infection (where the virus is quickly replicating), or a carrier state (where while you do have the infection, the virus is essentially dormant). In order to confirm that, testing for the hepatitis B virus DNA is recommended.

    Because the two viruses happen to share certain risk factors, concurrent testing for hepatitis C virus infection might not be a bad idea.
  2. The next step is to confirm presence of kidney disease, using tests described here.
  3. Finally, your physician will need to put two and two together. After the above two steps have been done, you still need to prove causality. Hence, a kidney biopsy will be necessary to confirm that kidney disease is indeed a result of hepatitis B virus, as well as the specific type of kidney disease. This is also because just having hepatitis B virus infection along with kidney disease doesn't necessarily prove that the infection is leading to kidney damage. One could have hepatitis B virus infection and have blood/protein in the urine from an entirely different reason (think, a diabetic patient with a kidney stone).
  4. Confirmation of final diagnosis and its cause has a huge impact on treatment plan as well. The disease states described above (PAN, MPGN, etc.) can be seen in people who do not have any hepatitis B virus infection. How we treat these kidney disease states in those situations will be entirely different from how they are treated when caused by hepatitis B virus.

    In fact, many treatments (like cyclophosphamide or steroids) which are used for treatment of non-hepatitis B-related MPGN or membranous nephropathy could actually do more harm than good if given to the patient with hepatitis B virus. This is because these treatments are designed to suppress the immune system, which is something the body needs to fight against Hepatitis B infection. Treatment with immunosuppresants in this situation could backfire and cause an increase in viral replication. Therefore, proving the cause is essential.

How Is Hepatitis B Virus-Related Kidney Disease Treated

Treat the cause. That is essentially the crux of the treatment. Unfortunately, no major randomized trials are available to guide treatment for kidney disease that happens because of hepatitis B virus infection. Whatever data we have from smaller observational studies support the use of antiviral therapy directed against hepatitis B infection as the linchpin of the treatment.

  1. Antiviral therapy: This includes medications like interferon alpha (which suppresses multiplication of hepatitis B virus and "modulates" the immune response to the infection), and other agents such as lamivudine, entecavir, etc. (these medications inhibit multiplication of the virus as well). They are finer nuances to treatment as far as the choice of agent used (further dependent on other factors like age, whether the patient has cirrhosis or not, the extent of the kidney damage etc). Which medication is chosen will also determine how long treatment can be continued for. These discussions are beyond the scope of this article and should be something that your physician will discuss with you before initiating treatment.
  2. Immunosuppressive agents: These include medications like steroids, or other cytotoxic medications like cyclophosphamide. While these might be used in the "garden-variety" kidney disease states of MPGN or membranous nephropathy, there use is typically not recommended when these disease entities are caused by hepatitis B virus (given risk of flaring up the infection). However, this is not a "blanket ban." There are specific indications when these agents might still need to be considered even in the setting of hepatitis B virus. One such exception is an exceptionally severe kind of inflammation that affects the kidneys' filter (called rapidly progressive glomerulonephritis). In that situation, immunosuppressive medications are usually combined with something called plasmapheresis.

Sources:

Hepatitis B and Renal Disease. Tak Mao Chan. Curr Hepat Rep. 2010 May; 9(2): 99–105. Published online 2010 Apr 14. doi:  10.1007/s11901-010-0042-6

Hepatitis B virus-associated polyarteritis nodosa: clinical characteristics, outcome, and impact of treatment in 115 patients. Guillevin L. Medicine (Baltimore). 2005 Sep;84(5):313-22.

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