Pathology Disorders of Blood Bleeding Coagulation Question And Answers

Bleeding Disorders

 

Question 1. Write a short note on disseminated intravascular Coagulation.
Answer:  

Disseminated intravascular coagulation is also termed as defirillar syndrome or consumption coagulopathy.

• It is a complex thrombohemorrhagic disorder occuring as secondary complication in some of the diseases.

Disseminated intravascular coagulation Etiology

• Massive Tissue Injury: In obstetrical syndrome, i.e. abruptioplacentae, amniotic fluid embolism, retained dead fetus.
  • Massive trauma
  • Metastatic malignancies
  • Surgery
• Infections: Endotoxiemia, septicemia, malaria, certain viral infection.
• Widespread Endothelial Damage: In aortic aneurysm
• • Hemolytic-uremic syndrome
  • Severe burn
• Miscellaneous: Snake bite, shock, heat stroke, acute intravascular hemolysis.

Read And Learn More: Pathology Question And Answers

Disseminated intravascular coagulation Pathogenesis

• Activation of coagulation: The etiological factors initiating widespread activation of coagulation pathway by release of tissue factors.
• Thromboitic phase: Endothelial damage from various thrombogenic stimuli causes generalized platelet aggregation and adhesion with resultant deposition of small thrombi and emboli throughout the microvasculature.
• Consumption phase: The thrombolytic phase is followed by a phase of consumption of coagulation factors and platelets.
• Secondary fibrinolysis: As a protective mechanism firinolytic system is secondary activation at the site of intravascular coagulation.

Disseminated intravascular coagulation Clinical Features

• Bleeding: The most common manifestation.
• Organ damage: Due to ischemia caused by widespread intravascular thrombosis such as kidney and brain.
• Less common manifestation includes microangiopathy, hemolytic anemia and thrombosis.

Disseminated intravascular coagulation Laboratory Diagnosis

• Platelet count is low.
• Blood film: Microangiopathic hemolytic anemia
• Prothrombin time, thrombin time is prolonged.
• Plasma firinogen levels are reduced.
• Fibrin degradation products are raised.

Question 2. Describe etiopathogenesis of bleeding disorders with lab diagnosis.
Answer:

Bleeding disorder or hemorrhagic diathesis are a group of disorder characterized by defective hemostasis with abnormal bleeding.

Bleeding disorder Etiopathogenesis

• Hemorrhagic diasthesis is due to vascular abnormalities:
  • Vascular bleeding disorder also called nonthrombocytopenic purpura or vascular purpuras are normally mild and characterized by petechiae, purpuras or ecchymoses confied to the skin and mucus membrane. Vascular bleeding disorders may be inherited or acquired.
• Hemorrhagic diasthesis due to platelet disorders:
  • Disorders of platelet function:
    • Defective platelet adhesion: Bernard-Soulier syndrome Von-Willebrand’s disease
      • • Defective platelet aggregation: Thrombasthenia
          • Disorders of platelet release reaction:
• Coagulation of disorder: A deficiency of each of the thirteen known plasma coagulation factors has been reported, which may be inherited or acquired.
  • Classic hemophilia (Hemophilia A): It occurs due to defiiency or reduced activity of factor 8. Patients of hemophilia suffr from bleeding for hours after the injury.
  • Von Willebrand’s disease

Question 3. Write a short note on hemophilia A.
Answer:

Classic hemophilia or hemophilia A is the second most common hereditary coagulation disorder.

• This is due to the defiiency or reduced activity of factor 8 (Antihemophilic factor)
• This disorder is inherited as a sex-linked recessive trait and therefore manifest clinically in males while females are the carriers.

Hemophilia A Pathogenesis

Hemophilia A is caused by quantitative reduction of factor 8 in 90% of cases while 10% cases have normal or increased level of factor 8 or either reduced activity.

Synthesis of factor 8 occurs in hepatic parenchymal cells and it regulates activation of factor X in intrinsic coagulation pathway.

Circulation of factor 8 occur in the blood which is complexed to another large protein, i.e. von Willebrand’s factor which consists of 99% of factor 8 – von Willbrand complex.

Genetic coding, synthesis and function of von Willebrand factor are diffrent as compared to those of factor 8. Normal hemostasis needs 25% of factor 8 activity.

Hemophilia A Clinical Features

• Patient with hemophilia suffrs from bleeding for hours or day after injury.
• Hemophilic bleeding can involve any bleeding but occurs most commonly as recurrent painful hemarthroses and muscle hematomas and sometimes hematuria.

Hemophilia A Laboratory Findings

• Whole blood coagulation time is prolonged in severe cases.
• Prothrombin time is usually normal.
• Activated partialthromboplastintime is typicallyprolonged.
• Specifi or assay for factor VIII show lowered activity.

Question 4. Discuss in brief hemophilia.
Or
Write short note on hemophilia.
Answer:

Hemophilia is a coagulation disorder.

• It occurs due to defiiency of coagulation factors.
• Types of hemophilia:
  • Christmas disease or hemophilia B: Inherited deficiency of factor 9. (Christmas Factor or plasma thromboplastin factor) produces Christmas disease or hemophilia B. Hemophilia B is rare than hemophilia A.

Question 5. Write a short note on Rh factor.
Answer:

• Rh factor is an antigen present in the RBC. The antigen was found in Rhesus monkey, so it was named as Rh factor.
• Rh antigen system has three closely linked gene loci, coding for D antigen (there is no d antigen), C and/or c antigen and E and/or e antigen. Thus, the antigens produced are C, D, E, c and e.
• An individual may have similar or diffrent sets of these three Rh antigens on each chromosome; for example, CDE/cde, cde/cde, or CdE/cdE (each person inherits one trio gene from each parent).
• Individuals who are positive for D antigen are considered Rh-positive (85% of the population) and those who lack it are Rh-negative.
• Individuals with a weak variant of D antigen, called the Du variant, are also considered Rh-positive.
• Alloimmunization, i.e. formation of an antibody against an antigen occurs if a person is exposed to an Rh antigen that is not on the patients RBCs.
• The majority of clinically important antibodies that produce a transfusion reaction are warm-reacting (IgG) antibodies (For Example, anti-D, anti- Kell) rather than cold-reacting (IgM) antibodies.

Question 6. Write a short note on eosinophilia.
Answer:

Eosinophils: They are granular white blood cells.

They have coarse, deep red staining granules in the cytoplasm and have usually two nuclear lobes.

• Eosinophils are involved in reactions to foreign proteins and to antigen-antibody reactions.
• An increase in the number of eosinophilic leucocytes above 400/ml is referred to as eosinophilia.

Eosinophilia

The causes are:

• Allergic disorders: Bronchial asthma, urticaria, drug hypersensitivity
• Parasitic infestations: Trichinosis, Echinococcosis, Intestinal parasitism
• Skin disease: Pemphigus, dermatitis, herpetiformis, erythemamultiforme
• Loeffler syndrome
• Tropical eosinophilia
• Pulmonary infiltration with eosinophilia syndrome.
• Haemophiliac disease: Chronic myeloid leukemia, pernicious anemia, Hogdkin’s disease, polycythemia vera
• Malignant disease
• Irradiation
• Miscellaneous disorders: Sarcoidosis, Rheumatoid arthritis, Polyarthritis nodosa.

Question 7.Write the difference between agglutination and precipitation reaction.
Answer:

Agglutination

• A type of antigen antibody reaction in which a solid antigen clumps together with a soluble antibody.
• Agglutination means the collection of separate particles into clumps.
• Blood typing is done on the basis of agglutination.

Precipitation

• In this the soluble antigens like tetanus toxins are converted into insoluble forms and then precipitated.
• In precipitation test precipitate forms in a solution containing a soluble antigen upon addition of serum containing the specifi precipitin.
• The reaction is specifi.
• This is used for the identifiation of unknown proteins, determinationoftype ofblood stains, types ofpneumococci and meningococci.