Hepatitis B Overview

Hepatitis is a general term that means inflammation of the liver. The liver can become inflamed as a result of infection, a disorder of the immune system , or exposure to alcohol, certain medications, toxins, or poisons.

• Hepatitis B is caused by infection with the hepatitis B virus (HBV). This infection has 2 phases: acute and chronic.
  • Acute (new, short-term) hepatitis B occurs shortly after exposure to the virus. A small number of people develop a very severe, life-threatening form of acute hepatitis called fulminant hepatitis.
  • Chronic (ongoing, long-term) hepatitis B is an infection with HBV that lasts longer than 6 months. Once the infection becomes chronic, it may never go away completely.
  • About 90-95% of people who are infected are able to fight off the virus so their infection never becomes chronic. Only about 5-10 percent of adults infected with HBV go on to develop chronic infection.
  • HBV infection is one of the most important causes of infection.
    

People with chronic HBV infectio n are called chronic carriers. About two-thirds of these people do not themselves get sick or die of the virus, but they can transmit it to other people. The remaining one third develop chronic hepatitis B, a disease of the liver that can be very serious.

The liver is an essential organ that the body needs to stay alive. Its most important functions are filtering many drugs and toxins out of the blood, storing energy for later use, helping with the absorption of certain nutrients from food, and p roducing substances that fight infections.

• The liver has an incredible ability to heal itself, but it can only heal itself if nothing is damaging it.
• Liver damage in chronic hepatitis B, if not stopped, continues until the liver becomes hardened and scarlike.
• Hepatitis B is the most common serious liver infection in the world. Worldwide, about 350 million people are chronic carriers of HBV, of whom, more than 250,000 die from liver-related disease each year.

• In the United States, hepatitis B is largely a disease of young adults aged 20-50 years. About 1.25 million people are chronic carriers, and the disease causes about 5000 deaths each year.

• The good news is that infection with HBV is almost always preventable. You can protect yourself and your loved ones from hepatitis B.

Hepatitis B Causes

• The hepatitis B virus is known as a blood-borne virus because it is transmitted from one person to another via blood.
  • saliva, which contain small amounts of blood, also carry the virus.
  • The virus c an be transmitted whenever any of these bodily fluids come in contact with the broken skin or a mucous membrane (in the mouth, genital organs, or rectum) of an uninfected person.

• People who are at increased risk of being infected with the hepatitis B virus include the following:
  • Men or women who have multiple sex partners, especially if they don't use a condom
  • Men who have sex with men
  • Men or women who have sex with a person infected with HBV
  • People with other STD ( sexually transmitted disease)
  • People who inject drugs with shared needles
  • People who receive transfusions of blood or blood products
  • People who undergo for kidney dialysis
  • Institutionalized mentally handicapped people and their attendants and family members
  • Health care workers who are stuck with needles or other sharp instruments contaminated with infected blood
  • Infants born to infected mothers

• In some cases, the source of transmission is never known.

• The younger you are when you become infected with the hepatitis B virus, the more likely you are to develop chronic hepatitis B. The rates of progression to chronic hepatitis B are as follows:
  • 90% of infants infected at birth
  • 30% of children infected at age 1-5 years
  • 6% of people infected after age 5 years
  • 5-10% of infected adults

• You cannot get hepatitis B from the following activities:
  • Being sneezed or coughed on
  • Hugging
  • Handshaking
  • Eating food or drinking water
  • Casual contact (such as an office or social setting)

When to Seek Medical Care

Call your health care provider if you have any of the following:

• Nausea and vomiting that does not go away in 1-2 days
• Yellow skin or eyes
• Dark-colored (like tea or cola) urine
• Pain in the abdomen

Either of these situations also warrants a call to your health care provider:

• You think that you might have been exposed to someone with hepatitis or that you might be at risk for any reason.
• You have other medical problems and think that you might have hepatitis.

If you are unable to reach your health care provider or have any of the following, go immediately to a hospital.

• Vomiting and cannot keep down any fluids

Exams and Tests

Since many people with hepatitis B do not have symptoms, they do not know they have the disease.

• Hepatitis B is often discovered accidentally when you see your health care provider for another reason.
• Blood tests done for an annual check-up, insurance purposes, or before surgery may show abnormalities in the liver blood test results.

If your health care provider determines that you may be at risk for contracting hepatitis, you will have blood drawn.

• The laboratory will examine the blood to determine how well your liver is functioning, if this has not already been done.
• Your blood will be tested to determine whether you have been exposed to certain hepatitis viruses and, possibly, other viruses.
• If you have had a large amount of vomiting or have not been able to take in liquids, your blood electrolytes may also be checked to ensure that your blood chemistry is in balance.
• Other tests may be ordered to rule out other medical conditions.

X-rays and other diagnostic images are needed only in very unusual circumstances.

Once you are diagnosed with chronic hepatitis B, you will see your health care provider regularly.

• At each visit, your blood will be checked to see whether the virus is multiplying in your blood and how quickly.
• Your liver function tests also will be checked each time.
• These results help decide when it is time to start treatment.

Other tests will be done to determine whether you should undergo treatment or to

decide on the best treatment.

• CT scan or ultrasound - These diagnostic imaging tests are used to detect the extent of liver damage.
• Liver biopsy - This involves removal of a tiny piece of the liver. It is usually done by inserting a long needle into the liver and withdrawing the tissue. The tissue is examined under a microscope to detect changes in the liver. A biopsy may be done to detect the extent of liver damage or to evaluate how well a treatment is working.

they have the disease.

• Hepatitis B is often discovered accidentally when you see your health care provider for another reason.
• Blood tests done for an annual check-up, insurance purposes, or before surgery may show abnormalities in the liver blood test results.

If your health care provider determines that you may be at risk for contracting hepatitis, you will have blood drawn.

• The laboratory will examine the blood to determine how well your liver is functioning, if this has not already been done.
• Your blood will be tested to determine whether you have been exposed to certain hepatitis viruses and, possibly, other viruses.
• If you have had a large amount of vomiting or have not been able to take in liquids, your blood electrolytes may also be checked to ensure that your blood chemistry is in balance.
• Other tests may be ordered to rule out other medical conditions.

X-rays and other diagnostic images are needed only in very unusual circumstances.

Once you are diagnosed with chronic hepatitis B, you will see your health care provider regularly.

• At each visit, your blood will be checked to see whether the virus is multiplying in your blood and how quickly.
• Your liver function tests also will be checked each time.
• These results help decide when it is time to start treatment.

Other tests will be done to determine whether you should undergo treatment or to decide on the best treatment.

• Histopathology - This involves removal of a tiny piece of the liver. It is usually done by inserting a long needle into the liver and withdrawing the tissue. The tissue is examined under a microscope to detect changes in the liver. A biopsy may be done to detect the extent of liver damage or to evaluate how well a treatment is working.

A bile duct is any of a number of long tube-like structures that carry bile.

Bile, required for the digestion of food, is excreted by the liver into passages that carry bile toward the hepatic duct, which joins with the cystic duct (carrying bile to and from the gallbladder) to form the common bile duct, which opens into the intestine.

The biliary tree is the whole network of various sized ducts branching through the liver.

The path is as follows: Bile canaliculi → Canals of Hering → interlobular bile ducts → intrahepatic bile ducts → left and right hepatic ducts merge to form → common hepatic duct exits liver and joins → cystic duct (from gall bladder) forming → common bile duct → joins with pancreatic duct → forming ampulla of Vater → enters duodenum

Common bile duct

The top half of the common bile duct is associated with the liver, while the bottom half of the common bile duct is associated with the pancreas, through which it passes on its way to the intestine. It opens in the part of the intestine called the duodenum into a structure called the ampulla of Vater.

1: Right lobe of liver 2: Left lobe of liver 3: Quadrate lobe of liver 4: Round ligament of liver 5: Falciform ligament 6: Caudate lobe of liver 7: Inferior vena cava 8: Common bile duct 9: Hepatic artery 10: Portal vein 11: Cystic duct 12: Common hepatic duct 13: Gallbladder

The gall-bladder and bile ducts laid open.

Pathology

Blockage of the bile duct by a cancer, gallstones, or scarring from injury prevents the bile from being transported to the intestine and the active ingredient in the bile (bilirubin) instead accumulates in the blood. This condition results in jaundice, where the skin and eyes become yellow from the bilirubin in the blood. This condition also causes severe itchiness from the bilirubin deposited in the tissues. In certain types of jaundice, the urine will be noticeably darker, and the stools will be much paler than usual. This is caused by the bilirubin all going to the bloodstream and being filtered into the urine by the kidneys, instead of some being lost in the stools through the ampulla of Vater.

Jaundice is commonly caused by conditions such as pancreatic cancer, which causes blockage of the bile duct passing through the cancerous portion of the pancreas; cholangiocarcinoma, cancer of the bile ducts; blockage by a stone in patients with gallstones; and from scarring after injury to the bile duct during gallbladder removal.

Additional images

Section across portal canal of pig. X 250.

An intraoperative cholangiogram, which is an X-Ray of the bile ducts during a laprascopic cholecystectomy.

The common hepatic duct is the duct formed by the convergence of the right hepatic duct (which drains bile from the right functional lobe of the liver) and the left hepatic duct (which drains bile from the left functional lobe of the liver). The common hepatic duct then joins the cystic duct coming from the gallbladder to form the common bile duct. The duct is usually 6–8cm length and 6mm in diameter in adults.

The hepatic duct is part of the biliary tract that transports secretions from the liver into the intestines. It carries more volume in people who have had their gallbladder removed.

It is an important anatomic landmark during surgeries such as gall bladder removal. It forms one edge of Calot's triangle, along with the cystic duct and the cystic artery. All constituents of this triangle must be identified to avoid cutting or clipping the wrong structure.

Fatty Liver

Definition of Fatty Liver

Fatty liver is the accumulation of fat in liver cells. It is also called steatosis.

Description of Fatty Liver

Possible explanations of fatty liver include the transfer of fat from other parts of the body or an increase in the extraction of fat presented to the liver from the intestine. Other explanations are that the liver reduces the rate it breaks down and removes fat. Eating fatty foods does not by itself produce a fatty liver.

Causes and Risk Factors of Fatty Liver

Alcohol, obesity, starvation, diabetes mellitus, corticosteroids, poisons (carbon tetrachloride and yellow phosphorus), Cushing's syndrome, and hyperlipidemia are some causes of fatty liver. Microvesicular fatty liver may be caused by valproic acid toxicity and high-dose tetracycline or during pregnancy.

Symptoms of Fatty Liver

Patients are often asymptomatic.

Diagnosis of Fatty Liver

The patient may have an enlarged liver or minor elevation of liver enzyme tests. Several studies show that fatty liver is one of the most common causes of isolated minor elevation of liver enzymes found in routine blood screening.

Images of the liver obtained by an ultrasound test, CT (computed tomography) scan, or MRI (magnetic resonance imaging) may suggest the presence of a fatty liver. To be certain whether a patient has fatty liver requires a liver biopsy, in which a small sample of liver tissue is obtained through the skin and analyzed under the microscope.

Treatment of Fatty Liver

The treatment of fatty liver is related to the cause. It is important to remember that simple fatty liver may not require treatment. The benefit of weight loss, dietary fat restriction, and exercise i n obese patients is inconsistent.

Reducing or eliminating alcohol use can improve fatty liver due to alcohol toxicity. Controlling blood sugar may reduce the severity of fatty liver in patients with diabetes. Ursodeoxycholic acid may improve liver function test results, but its effect on improving the underlying liver abnormality is unclear.

cirrhosis

Cirrhosis is a complication of many liver diseases that is characterized by abnormal structure and function of the liver. The diseases that lead to cirrhosis do so because they injure and kill liver cells, and the inflammation and repair that is associated with the dying liver cells causes scar tissue to form. The liver cells that do not die multiply in an attempt to replace the cells that have died. This results in clusters of newly-formed liver cells (regenerative nodules) within the scar tissue. There are many causes of cirrhosis; they include chemicals (such as alcohol, fat, and certain medications), viruses, toxic metals (such as iron and copper that accumulate in the liver as a result of genetic diseases), and autoimmune liver disease in which the body's immune system attacks the liver.

cirrhosis cause problems

The liver is an important organ in the body. It performs many critical functions, two of which are producing substances required by the body, for example, clotting proteins that are necessary in order for blood to clot, and removing toxic substances that can be harmful to the body, for example, drugs. The liver also has an important role in regulating the supply to the body of glucose (sugar) and lipids (fat) that the body uses as fuel. In order to perform these critical functions, the liver cells must be working normally, and they must have an intimate relationship with the blood since the substances that are added or removed by the liver are transported to and from the liver by the blood.

The relationship of the liver to the blood is unique. Unlike most organs in the body, only a small amount of blood is supplied to the liver by arteries. Most of the liver's supply of blood comes from the intestinal veins as the blood returns to the heart. The main vein that returns blood from the intestines is called the portal vein. As the portal vein passes through the liver, it breaks up into increasingly smaller and smaller veins. The tiniest veins (called sinusoids because of their unique structure) are in close contact with the liver cells. In fact, the liver cells line up along the length of the sinusoids. This close relationship between the liver cells and blood from the portal vein allows the liver cells to remove and add substances to the blood. Once the blood has passed through the sinusoids, it is collected in increasingly larger and larger veins that ultimately form a single vein, the hepatic vein that returns the blood to the heart.

In cirrhosis, the relationship between blood and liver cells is destroyed. Even though the liver cells that survive or are newly-formed may be able to produce and remove substances from the blood, they do not have the normal, intimate relationship with the blood, and this interferes with the liver cells' ability to add or remove substances from the blood. In addition, the scarring within the cirrhotic liver obstructs the flow of blood through the liver and to the liver cells. As a result of the obstruction to the flow of blood through the liver, blood "backs-up" in the portal vein, and the pressure in the portal vein increases, a condition called portal hypertension. Because of the obstruction to flow and high pressures in the portal vein, blood in the portal vein seeks other veins in which to return to the heart, veins with lower pressures that bypass the liver. Unfortunately, the liver is unable to add or remove substances from blood that bypasses it. It is a combination of reduced numbers of liver cells, loss of the normal contact between blood passing through the liver and the liver cells, and blood bypassing the liver that leads to many of the manifestations of cirrhosis.

symptoms and signs

Patients with cirrhosis may have few or no symptoms and signs of liver disease. Some of the symptoms may be nonspecific, that is, they don't suggest that the liver is their cause. Some of the more common symptoms and signs of cirrhosis include:

• Yellowing of the skin (jaundice) due to the accumulation of bilirubin in the blood
• Fatigue
• Weakness
• Loss of appetite
• Itching
• Easy bruising from decreased production of blood clotting factors by the diseased liver.

Patients with cirrhosis also develop symptoms and signs from the complications of cirrhosis

The polymerase chain reaction (PCR)

The polymerase chain reaction (PCR) is a technique widely used in molecular biology, microbiology, genetics, diagnostics, clinical laboratories, forensic science, environmental science, hereditary studies, paternity testing, and many other applications. The name, polymerase chain reaction, comes from the DNA polymerase used to amplify (replicate many times) a piece of DNA by in vitro enzymatic replication. The original molecule or molecules of DNA are replicated by the DNA polymerase enzyme, thus doubling the number of DNA molecules. Then each of these molecules is replicated in a second "cycle" of replication, resulting in four times the number of the original molecules. Again, each of these molecules is replicated in a third cycle of replication. This process is known as a "chain reaction" in which the original DNA template is exponentially amplified. With PCR it is possible to amplify a single piece of DNA, or a very small number of pieces of DNA, over many cycles, generating millions of copies of the original DNA molecule. PCR has been extensively modified to perform a wide array of genetic manipulations, diagnostic tests, and for many other uses.

What is PCR used for?

The polymerase chain reaction is used by a wide spectrum of scientists in an ever-increasing range of scientific disciplines. In microbiology and molecular biology, for example, PCR is used in research laboratories in DNA cloning procedures, Southern blotting, DNA sequencing, recombinant DNA technology, to name but a few. In clinical microbiology laboratories PCR is invaluable for the diagnosis of microbial infections and epidemiological studies. PCR is also used in forensics laboratories and is especially useful because only a tiny amount of original DNA is required, for example, sufficient DNA can be obtained from a droplet of blood or a single hair.

Liver and Hepatitis C

Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). It is difficult for the human immune system to eliminate the virus from the body, and infection with HCV usually becomes chronic. Over decades, chronic infection with HCV damages the liver and can cause liver failure in some people.

In the U.S., the number of new cases of infection with HCV has declined over the last 10 years from a peak of some 200,000 annually to about 19,000 in 2006. When the virus first enters the body, there usually are no symptoms, so these numbers are estimates. Up to 85% of newly infected people fail to clear the virus and become chronically infected. In the U.S., more than three million people are chronically infected with HCV. Infection is most common among people who are 40 to 60 years of age, reflecting the high rates of infection in the 1970s and 1980s. There are 8,000 to 10,000 deaths each year in the U.S. related to HCV. HCV is the leading cause of liver transplantation in the U.S and is a risk factor for liver cancer.

Laboratory Blood Tests..

Doctors depend on many different laboratory tests of blood samples to diagnose and monitor diseases. Because the liquid portion of the blood (plasma) carries so many substances essential to the body's functioning, blood tests can be used to find out what is happening in many parts of the body.

Testing blood is easier than obtaining a tissue sample from a specific organ. For example, thyroid function can be evaluated more easily by measuring the level of thyroid hormones in the blood than by directly sampling the thyroid. Likewise, measuring liver enzymes and proteins in the blood is easier than sampling the liver. However, certain blood tests are used to measure the components and function of the blood itself. These are the tests that are mostly used to diagnose blood disorders.

Complete Blood Count:

The most commonly performed blood test is the complete blood count (CBC), which is an evaluation of all the cellular components (red blood cells, white blood cells, and platelets). Automated machines perform this test in less than 1 minute on a small drop of blood. The CBC is supplemented in some instances by examination of blood cells under a microscope.

The CBC determines the number of red blood cells and the amount of hemoglobin (the oxygen-carrying protein in red blood cells) in the blood. In addition, the average size, degree of variability of size, and hemoglobin content of red blood cells is assessed by a CBC and can alert laboratory workers to the presence of abnormal red blood cells (which may then be further characterized by microscopic examination). Abnormal red blood cells may be fragmented or shaped like teardrops, crescents, needles, or a variety of other forms. Knowing the specific shape and size of red blood cells can help a doctor diagnose a particular cause of anemia. For example, sickle-shaped cells are characteristic of sickle cell disease, small cells containing insufficient amounts of hemoglobin are likely due to iron deficiency anemia, and large oval cells suggest anemia due to a deficiency of folic acid or vitamin B₁₂.

The CBC also determines the number of white blood cells. The specific types of white blood cells can be counted (differential white blood cell count) when a doctor needs more information. If the total number of white blood cells or the number of one of the specific types of white blood cells is above or below normal, the doctor can examine these cells under a microscope. The microscopic examination can identify features that are characteristic of certain diseases. For example, large numbers of white blood cells that have a very immature appearance (blasts) may indicate leukemia (cancer of the white blood cells).

Platelets are usually also counted as part of a CBC. The number of platelets is an important measure of the blood's protective mechanisms for stopping bleeding (clotting). A high number of platelets (thrombocytosis or thrombocythemia) can lead to blood clots in small blood vessels, especially those in the heart or brain. In some disorders, a high number of platelets may paradoxically result in excess bleeding.

Microbiology Medical Laboratory Technicians

Performs routine and specialized procedures, reviews and approves clinical test results for use in the diagnosis and treatment of patients in accordance with established protocols for a laboratory performing high complexity procedures as defined by the standards of the Clinical laboratories.
Performs tests for the detection and/or identification of infectious agents; Performs tests for the determination of organism antimicrobial susceptibility; Performs other routine and specialized procedures in accordance as specified in the primary function, in a manner which assures an efficient work flow and a test turnaround time within the established limits designated in the department's scope of service; Produces clear, concise and accurate electronic and/or written patient reports; Provides clear, concise and accurate verbal patient reports with appropriate written or electronic documentation; Reviews patient reports, logs, etc.; for accuracy, clarity and completeness, making corrective action as needed; Operates and maintains equipment necessary for the function of and provision of services by the department; performs preventive and corrective instrument maintenance/repairs and maintains records of actions; Recognizes and troubleshoots technical and administrative problems, and initiates corrective action.
Works with infectious and hazardous substances; Follows the laboratory's procedures for specimen handling and processing, test analyses, reporting and maintaining records of patient test results; Capable of identifying problems that may adversely affect test performance or reporting of test results and either must correct the problems or immediately notify a Medical Technologist.
Laboratory Manager, Director or Laboratory Pathologist; Documents all corrective actions taken when test systems deviate from the laboratory's established performance specifications; Ensures that patient test results are not reported until all corrective actions have been taken and the test system is functioning properly; Assists in the training and competency evaluation of other testing personnel, to include the documentation of the performance of individuals responsible for patient testing; Assists with the evaluation of test methodology appropriate for the clinical use of the test results; Assist in the verification of test procedures performed and the establishment of the laboratory's test performance characteristics; Incorporates the goals and mission and the Organization Integrity Plan of Trinity Health and Holy Cross Hospital into daily work; Performs proper inventory, maintenance and storage of media, reagents, supplies, equipment and records; Performs other related duties as assigned.