7 Flashcards
VIRAL HEPATITIS
reserved for infection of the liver caused by a small group of viruses having a particular affinity for the liver?
Systemic viral infections ?
Hepatitis viruses A (HAV), B (HBV), C (HCV), D (HDV), and E (HEV).
Hepatitis G virus (HGV) is not pathogenic
Systemic viral infections that can involve the liver include:
1) infectious mononucleosis (Epstein-Barr virus), → mild hepatitis
2) Cytomegalovirus particularly in the newborn or immunosuppressed;
3) yellow fever,
VIRAL HEPATITIS
CLINICOPATHOLOGICAL TYPES
1- Asymptomatic acute infection:
- Identified accidentally by : mild ↑ in serum aminotransferases &(serologic evidence only)
presence of antiviral Antibodies
2- Acute viral Hepatitis: Caused by HAV, HEV, HBV, or ± HCV.
(AST= aspartate aminotransferase, GOT?) (ALT= alanine aminotransferase, GPT √√)
3- Fulminating Hepatitis: Caused by HEV, HAV, HBV, submassive to massive hepatic necrosis with acute liver failure
4- Chronic Hepatitis: Caused by HCV, HBV, HDV
with or without progression to cirrhosis, persistent elevations of serum aminotransferase levels.
5- Chronic carrier: caused mainly by HBV, or ± HCV.
- an individual without manifest symptoms who harbors & so can transmit an organism.
(asymptomatic without apparent disease)
Acute viral Hepatitis:
Four phases:
1- Incubation period:
2- Preicteric phase:
- nonspecific constitutional symptoms as:
- malaise, fatigability, nausea, loss of appetite
, - low-grade fever, headaches, muscle and joint aches
3- Icteric phase:
- Jaundice appears (mainly conjugated hyperbilirubinemia),
→ yellowish sclera, dark-colored urine (dt conjugated bilirubin), light colored stools (due to cholestasis), pruritis (due to retention of bile salts),With hepatocellular damage → consequent defect in bilirubin conjugation,
so, unconjugated hyperbilirubinemia can also occur.
- Enlarged tender liver
- Elevated serum aminotransferase levels
4- Convalescence: jaundice & most symptoms disappear in few weeks
Peak of infectivity: during last days of incubation period & early days of acute symptoms
Acute viral Hepatitis Gross, Microscopy, Fate
Gross: Liver is enlarged and reddened; ± greenish if cholestatic
Microscopy: - Hydropic (ballooning) degeneration of hepatocytes.
- Necrosis of hepatocytes: isolated cells or clusters obtain
- Inflammatory cells (lymphocytes, macrophages) around necrotic cells, in sinusoids & in the adjacent portal tracts.
- Cholestasis: bile plugs in canaliculi & bile inside the cytoplasm of hepatocytes
- Framework of the liver is not affected.
Fate: acute viral hepatitis may terminate by one of three possibilities:
1- Complete recovery in 95% or more as in hepatitis A infections.
2- Acute fulminating hepatitis: may occur with HEV (during pregnancy), HAV & HBV)
3- Chronic hepatitis or chronic carrier: may occur with HCV, HBV.
Fulminant Viral Hepatitis
Pathology
There is severe necrosis which may be massive affecting most of the hepatic parenchyma, or submassive (less severe).
1- Acute Massive Necrosis: - Diffuse liver cell necrosis → The patient dies in few days due to liver failure.
2- Subacute Massive Necrosis:
- The patient dies within few weeks from liver failure or may rarely survive longer and develop post-necrotic cirrhosis.
Chronic Viral Hepatitis
Definition Etiology, C/P
Chronic inflammation viral liver disease manifested clinically and serologically for more than 6 months
Etiology: most common: HCV, HBV, HDV
C/P: fatigue, malaise, loss of appetite, bouts of mild jaundice. spider angiomas, palmar erythema, mild hepatomegaly, hepatic tendernessand
Chronic Viral Hepatitis
Laboratory studies:
persistent elevations of serum aminotransferase levels,
prolongation of the prothrombin time and, in some instances,hypergammaglobulinemia,
hyperbilirubinemia, and mild elevations in alkaline phosphatase levels
The major causes of death in patients with chronic hepatitis
cirrhosis, namely, liver failure, hepatic encephalopathy, massive cirrhosis
hematemesis from esophageal varices, and hepatocellular carcinoma
Chronic Viral Hepatitis Microscopic Features:
1- lnflammation: - mainly lymphocytes in portal tracts, but may extend to periportal are area causing necrosis of periportal hepatocytes (= Piecemeal necrosis or Interface hepatitis)
2- Necrosis of hepatocytes:
- It may be piecemeal necrosis or in severe cases multiacinar or bridging necrosis) connecting portal-to-portal, central-to-central, or portal-to-central regions of adjacent lobules, signifying a more severe form of acute hepatitis.
3- Fibrosis: (range absent to very marked). - It may be portal fibrosis → periportal fibrosis → followed with time by bridging fibrosis → finally resulting in cirrhosis, with fibrous septa and hepatocyte regeneration nodules.
4- Other Features:
- Ballooning of hepatocytes. - Fatty change of hepatocytes - Ground glass hepatocytes (in case of HBV)
- Cholestasis (in severe cases)
- Hepatocellular dysplasia (precancerous)
Grading and staging of Chronic Hepatitis - Using:
1- Scoring system for the Grade (degree) of necro-inflammatory activity & 2- Scoring system for Stage of fibrosis.
Grading & staging correlate with prognosis and response to interferon therapy
Types Of Chronic Hepatitis (Old Classification)
1- Chronic Persistent Hepatitis:
- mild portal inflammation (mainly lymphocytes) and there is No or minimal necrosis.
2- Chronic Active (Aggressive) Hepatitis:
- there is portal and lobular inflammation, Necrosis, Fibrosis
Complications Of Chronic Hepatitis:
1- Post hepatitic cirrhosis.
2- Liver failure. 3- Hepatocellular carcinoma.
LIVER ABSCESS
Etiology
In developing countries liver abscesses usually result from Parasitic infections:
- Amebic liver abscess: cause: Entamoeba histolytica
- lnfected hydatid cyst: cause: Echinococcus granulosus
Western world, liver abscesses usually result from Bacterial infections:
- complicating ascending cholangitis: E coli → usually multiple
- Blood spread (portal or systemic pyaemia) → Pyaemic abscesses, multiple glsolitary multiple
- direct spread to the liver from a nearby source, → usually solitary
- Following a penetrating injury.→ usually solitary
Gross , C/P: LIVER ABSCESS
Gross:
- May be solitary or multiple, ranging from few millimeters to massive lesions - consisting of necrotic tissue with abundant neutrophils. ± Bacteria, fungi or parasites
C/P: fever with right upper quadrant pain and tender hepatomegaly ± Jaundice
