Q. 2. Describe the laboratory investigations for bleeding and clotting disorders.
Ans. Various laboratory diagnostic tests for bleeding and clotting disorders are as follows:
Investigation of disordered vascular haemostasis
Disorders of vascular haemostasis may be due to vascular permeability, reduced capillary strength and failure to contact after injury.
• This simplest test is based on the principle of formation of haemostatic plug following standard incision on volar surface of forearm and the time the incision takes to stop bleeding is measured the test is dependent upon capillary function as well as on platelet number and ability of platelets to adhere to form aggregates.
• Normal range is 3–8 minutes.
• A prolonged bleeding time may be seen due to
• disorder of platelet function, for example von Willebrand disease;
• vascular abnormalities, for example Ehlers–Danlos syndrome; and
• severe deficiency of factor V and II.
Hess capillary resistance test (Tourniquet test)
• This test is done by placing sphygmomanometer cuff to the upper arm and raising the pressure in it between diastolic and systolic for 5 min.
• After deflation, the number of petechia appearing in the next 5 min in 3 cm area over the cubital fossa is counted.
• Presence of more than 20 petechiae is considered a positive test. The test is positive in increased capillary fragility as well as in thrombocytopenia.
Investigation of platelet and platelet function
• Haemostatic disorder is most commonly due to abnormalities is platelet number, morphology or function.
• Screening tests carried out for assessing peripheral blood platelet count is skin bleeding time.
• Examination of fresh blood film to see the morphologic abnormalities of platelets.
• If these screening tests suggest a disorder of platelet function, the following platelet function tests may be carried out.
i. Platelet adhesion test: such as retention in a glass bead column, and other sophisticated techniques.
ii. Aggregation test: which are turbidimetric techniques using ADP, collagen or ristocetin.
iii. Granular content of platelets and their release can be assessed by electron microscopy.
Tests for coagulative defect
• Clotting time
• Thrombin time
• Prothrombin time
• Thromboplastin generation time
• Partial thromboplastin time.
Q. 3. What are the aetiological factors for the spontaneous bleeding from gingiva? Describe the oral manifestations of myelogenous leukaemia.
How do you manage a case of myeloid leukaemia patient visiting dental hospital.
The various causes of bleeding in the oral cavity are as follows:
• Postextraction, postsurgical, posttraumatic.
• Infections—viral, bacterial fungal, parasitic and spirochete.
• Oral ulcerative lesions—stomatitis, glossitis, etc.
• Oral exophytic soft tissue lesions—pyogenic granuloma, pregnancy tumour.
• Local irritants leading to gingivitis and periodontitis.
• Rupture of blood containing bulla.
• Congenital hamartomas—haemangioma, hereditary haemorrhagic telangiectasia.
• Arteriovenous malformation.
Haemorrhage due to platelet disorders
• Glanzmann’s disease
• Aldrich syndrome.
Haemorrhage due to coagulation diseases
• Christmas disease
• von Willebrand disease
• Deficiency of Stuart factor
• Multiple myeloma
• Systemic lupus erythematosus
• Diffuse intravascular coagulation
Haemorrhage due to systemic diseases
• Diabetes mellitus
• Septic embolism in bacterial endocarditis
• Systemic viral infection
• Anticoagulant therapy
• Graft versus host reaction
• Sturge–Weber syndrome.
Leukaemia is a disease characterized by the progressive over production of white blood cells, which usually appear in the circulating blood in an immature form.
• Depending on the onset and the course of the leukaemia it is classified as:
a. Acute leukaemia
b. Chronic leukaemia
• Depending on the type of cell of origin leukaemia is also classified into:
a. Myeloid (myelogenous) leukaemia and
b. Lymphoid (lymphoblastic, lymphocytic) leukaemia.
Acute and chronic leukaemias are broadly classified as:
i. Acute lymphoblastic leukaemia (ALL)
ii. Acute myeloblastic leukaemia (AML)
iii. Chronic lymphocytic leukaemia (CLL)
iv. Chronic myelocytic leukaemia (CML).
• However, some are associated with ionizing radiation, cytotoxic drugs, chemical carcinogens and infectious origin of unknown organism.
• Other predisposing factors may be chromosomal abnormalities, genetics, age, hormones, immune competence and stress.
• Acute lymphoblastic leukaemia is common in children while acute myeloid leukaemia is common in adults.
• Sudden onset.
• Characterized by weakness, fever, headache, petechial or ecchymotic haemorrhages in the skin and mucous membranes.
• Lymphadenopathy is often the first sign of the disease.
• Gingival bleeding, epistaxis, haemorrhage may occur due to thrombocytopenia.
• Bleeding may occur due to disseminated intravascular coagulation (DIC), which is mainly in patients with acute promyelocytic leukaemia.
• Hepatomegaly, splenomegaly, gum hyperplasia, stomatitis, sternal tenderness, enlargement and infiltration of skin may be seen.
• Disease is present before the symptoms are seen.
• Patient may appear with excellent health or exhibit emaciation suggestive of a chronic debilitating disease.
• Lymph node enlargement common in CLL but uncommon in CML.
• Splenomegaly and hepatomegaly are fully developed due to protracted course of the disease.
• Enlargement of salivary glands and tonsils leading to leukaemic infiltration and xerostomia.
• Petechiae, ecchymosis of skin. Papules, pustules, bullae, areas of pigmentation, herpes zoster, itching and burning sensations are also seen.
• Oral lesions occur in both acute and chronic forms.
• Gingivitis, gingival hyperplasia, haemorrhage, petechiae and ulceration of the mucosa.
• Rapid loosening of the teeth due to necrosis of PDL.
• Alterations in the developing tooth crypts.
• Osseous changes in jaws.
a. Peripheral blood examination reveals the presence of blast cells with high, low or normal total leukocyte count.
b. There is also the evidence of anaemia and thrombocytopenia.
c. The bone marrow examination shows hypercellularity along with the presence of >20 % leukaemic blast cells.
d. Cytochemical staining, cytogenetics and immune-phenotyping of the cells help in differentiating different types of leukaemia.
• The management of acute leukaemia consists of supportive and specific treatment.
• Anaemia is managed with infusion of red cell concentrate. Platelet transfusion is needed to treat bleeding manifestations and to maintain platelet count above 10,000–20,000/mm3.
• The objective of specific treatment is to eliminate leukaemic cells without affecting the normal cells. However, the therapy may be associated with high morbidity and mortality. Hence, the decision to administer a specific therapy to a particular patient is based on the age, type of leukaemia and the presence of other associated illnesses.
• In chemotherapy, a combination of various cytotoxic drugs is given under a standard protocol. The first step is to achieve remission (normal blood counts, normal bone marrow, and normal clinical status). The initial induction phase is followed by the consolidation phase and the maintenance phase.
• Cranial irradiation along with intrathecal methotrexate is given in ALL patients for CNS prophylaxis.
Bone marrow transplantation
• If a patient relapses after chemotherapy, remission is difficult to induce, then bone marrow transplantation is advised in such cases.
Q. 4. Classify anaemias. Discuss in detail the oral manifestations, diagnosis and management of pernicious anaemia.
Define and classify anaemias. Discuss in detail about iron deficiency anaemia.
Classify anaemias. Describe clinical features and laboratory diagnosis of iron deficiency anaemia.
Ans. Anaemia is defined as an abnormal reduction in the number of circulating red blood cells, the quantity of haemoglobin and the volume of packed red cells in a given unit of blood. The normal haemoglobin level varies from 14 to 16 g/dl in the adult male and 12 to 14 g/dl in the female.
Anaemia has been traditionally classified into:
• Haemorrhagic and
• Haemolytic anaemia.
According to the morphology (MCV, MCH and MCHC) into the following types:
However, the recent classification is based on reticulocyte index, which is a measure of RBC production:
• The reticulocyte index is increased (>2.5) due to increase in erythropoiesis in haemolytic and haemorrhagic anaemias.
• A low reticulocyte index <2% shows decreased marrow production or maturation defects during erythropoiesis.
Aetiologic classification of the anaemias
I. Blood loss
• Acute posthaemorrhagic blood loss
• Chronic posthaemorrhagic blood loss
II. Deficiency of haemopoietic factors
• Iron deficiency
• Folate and vitamin B12 deficiency
• Protein deficiency, i.e. diarrhoea, malabsorption
III. Bone marrow aplasia
• Aplastic anaemia
• Pure red cell aplasia
IV. Anaemia due to systemic infections or systemic disorders
• Anaemia due to chronic infection
• Anaemia due to chronic renal disease
• Anaemia due to chronic liver disease
• Disseminated malignancy
• Endocrinal diseases
V. Anaemia due to bone marrow infiltration
• Congenital sideroblastic anaemia
VI. Anaemia due to increased red cell destruction (haemolytic anaemia)
• Intracorpuscular defect (hereditary or acquired)
• Extracorpuscular defect (acquired).
(Vitamin B12 deficiency, Addisonian anaemia)
Pernicious anaemia is a type of a chronic progressive, megaloblastic anaemia of adults and is caused by deficiency of intrinsic factors in stomach.
• It is probably an autoimmune disorder with a genetic predisposition and the disease is associated with human leukocyte antigen (HLA) types A2,A3,B7 and A blood group.
• Occurs rarely before 30 years of age and increases in frequency with advancing age.
• No racial predilection, in other countries except in US females are more commonly affected.
• The four major cardinal features of pernicious anaemia are:
a. Abnormally large RBCs
c. Neurologic and gastrointestinal symptoms
d. A fatal outcome unless the patient receives life-long injections of vitamin B12.
• Generalized weakness, fatigue, headache, palpitation, nausea, vomiting, anorexia and diarrhoea.
• Shortness of breath, dyspnoea, loss of weight, pallor and abdominal pain.
• Patients have smooth, dry and yellow skin.
• Neurological manifestations include tingling sensation in hands and feet, paraesthesia of extremities due to peripheral nerve degeneration.
• Glossitis, glossodynia (painful tongue) and glossopyrosis (itching and burning tongue).
• Tongue appears beefy red in colour.
• Sometimes loss of papilla produces a bald appearance of tongue which is referred to as Hunter glossitis or Moeller glossitis.
• Sometimes hyper pigmentation occurs in mucosa.
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