Wednesday, December 29, 2010

HCV-Rheumatic Disorders

Several forms of arthritis have been linked to HCV infection but this is rare. The type most commonly associated with hepatitis C is rheumatoid arthritis (RA). Blood levels of people with HCV often show elevated levels of rheumatoid factor and it is thought that this may be a trigger to the development of rheumatoid arthritis.

RA normally affects the synovial joints (see figure 1). These are joints with a space between them that is filled with a liquid called synovial fluid. Most joints in the body are of this type. RA causes membranes in these joints to overgrow causing inflammation of the linings of the joints.

Related 2010: Synovial Biopsy Findings in Arthritis Associated with Hepatitis C Virus Infection

Figure 1

Symptoms include pain, swelling, redness and stiffness. As the condition progresses invading inflammatory proteins may damage surrounding cartilage, tendons and bone so affecting joint movement. It is generally thought that HCV related RA is an autoimmune disorder that results in antibodies starting to attack normal body tissue, but some doctors think it may be more closely related to liver damage and argue that the fact that the condition usually affects people who have progressed to cirrhosis supports this.

Treatment can be a problem in that some anti-inflammatory drugs used to treat autoimmune diseases can suppress the immune system and may lead to increased viral replication. Another concern is that many of the drugs used to treat RA are metabolised by the liver so that in people with liver damage toxins may build up in the liver. There is evidence that drug treatment which reduces the viral load can decrease arthritic symptoms.

The hepatitis C virus (HCV) can cause arthritis, muscle pain and weakness, and vascular problems in addition to liver disorders. These associated inflammatory musculoskeletal disorders are very common in individuals infected with the virus and the resulting chronic hepatitis. In fact, these disorders can appear before the patient is even diagnosed with HCV.

What are HCV-associated rheumatic diseases?
HCV-associated rheumatic diseases are disorders of the joints and muscles that can result from the HCV virus. Painful joints and muscles combined with fatigue are usually the first and most common complaints.
Less common, but just as important, rheumatic disorders that can occur include joint swelling and inflammation of blood vessels (vasculitis).
What causes HCV-associated rheumatic diseases?
The musculoskeletal complications of HCV-associated rheumatic disorders are a reaction to the immune system's fight against the virus. This leads to the formation of immune complexes (formed by the HCV or "antigen" combining with the patient's antibody against HCV) as well as the production of abnormal proteins called cryoglobulins.


This is a disorder in which abnormal proteins may cause damage to the skin, nervous system and kidneys. Symptoms include mild fatigue, joint pains, or itching and increased sensitivity to temperature changes.
Occasionally, people with cryoglobulinemia develop inflammation of the blood vessels (vasculitis) which can cause purple skin lesions (purpura) or numbness in the hands and feet or Raynauds phenomenon where the hands turn white, then blue, and then red from constriction and subsequent dilation of the blood vessels).
White fingertips are an example of Raynaud's phenomenon.

Women living in the northeastern United States are more likely to develop rheumatoid arthritis (RA), suggesting a link between the autoimmune disease and vitamin D deficiency, says a new study led by a Boston University School of Public Health researcher.
In the paper, which appears online in the journal Environmental Health Perspectives, a spatial analysis led by VerĂ³nica Vieira, MS, DSc, associate professor of environmental health, found that women in states like Vermont, New Hampshire and southern Maine were more likely to report being diagnosed with RA.

"There's higher risk in the northern latitudes," Vieira said. "This might be related to the fact that there's less sunlight in these areas, which results in a vitamin D deficiency."

The study looked at data from the Nurses' Health Study, a long-term cohort study of U.S. female nurses. Looking at the residential addresses, health outcomes and behavioral risk factors for participants between 1988 and 2002, researchers based their findings on 461 women who had RA, compared to a large control group of 9,220.

RA is a chronic inflammatory disease that affects the lining of the joints, mostly in the hands and knees. This chronic arthritis is characterized by swelling and redness and can wear down the cartilage between bones. RA is two to three times more common in women than in men.
Although the cause of RA is unknown, the researchers wrote, earlier studies have shown that vitamin D deficiency, which can be caused by a lack of sunlight, has already been associated with a variety of other autoimmune diseases.

Food For Thought:
According to a study in the July 28, 2009 issue of World Journal of Gastroenterology, bone loss and vitamin D deficiency were found to be common among people with liver cirrhosis. We know liver cirrhosis can be a potential outcome of HCV and HBV.
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