7/30/2019 Hematology - Blood Films http://slidepdf.com/reader/full/hematology-blood-films 1/13 Hematology FBC Hb 13-15 WBC 4-10 Platelets 150-400 MCV 85-95 Case 2 60yo female: Hb 7.2, WBC 12, Platelets 470, MCV 71 What are the causes of hypochromic, microcytic red cells? -Iron deficiency 98% -Thalassemia intermedia coz of age -Lead poisoning, sideroblastic anemia, anemia of chronic dz (rare) Blood film -pale centre in the middle -Pale area should not exceed >1/3 area of RBC Causes of Fe deficiency (a)Females Young – menorrhagia GI bleed Tests used for Ix of Fe deficiency -Colonoscopy + OGD to find blding source esp in post menopausal -don’t waste time on fobt
- Hereditary (1%) coombs test negative, born with spherocytes
- Acquired (99%)
Develop antibodies against the RBC membrane (autoimmune haemolytic anemia)
What are the necessary lab tests: direct coombs test! dist acquired fm non acquired Positive direct Coomb’s test for acquired form
Coomb’s test looks for antibodies – direct looks for presence of antibodies onsurface of RBCs; indirect looks for freely floating antibodies in patient’s
plasma
E.g. direct coomb’s test of baby’s blood, indirect of mother’s blood
Causes of acquired autoimmune haemolytic anemia
Infective Mycoplasma
Inflammatory SLE
Sjogren’s disease
Neoplastic Lymphoma
leukemia
Drugs PENICILLIN
Methyldopa
Mefenamic acid
Idiopathic (50%)
AIHA is most often caused in great part due to the inability of corrupted IgM
produced by CLL cells to control the IgG produced by normal B-cells. IgG can and
does attack "self antigens", if it is not controlled by proper functioning of IgM.
One way of handling this is to use intravenous injections of Ig obtained from healthy
blood donors, which contain the good and effective variety of Ig. Viral or bacterial infections that cause danger signals to be sent out can get the
immune system go into over-drive. Lactate dehydrogenase is one of these danger
signals, and any viral infection that causes increase in LDH will activate
macrophages, which may exacerbate AIHA
AIHA treatment
A tried-and-true approach to treating AIHA is corticosteroid drugs such as
prednisone. These drugs control AIHA by immune suppression, reducing the level of
inflammation, reducing the level of T-cell and macrophage activation. But steroiddrugs by their very nature also expose patients to increased risk of infections and even
secondary cancers.
Since the bulk of the red blood cells are killed by activated macrophages from the
spleen, one drastic way of controlling AIHA is to remove the spleen surgically. Or,
one can look to recent studies where low-toxicity liposomal drugs such as clodronate
have been effective in targeting splenic macrophages (in mice studies).
the viral or bacterial infection may well do the job of reducing the LDH, reduce
macrophage activation, reduce the killing of red blood cells.
case 5; Chronic haemolytic anaemia: Hereditary spherocytosis
Most common cause of hereditary haemolytic anaemia in people of Northern Europeanheritage
Rare locally Pathogenesis
AD inheritance in 75% Affects membrane protein spectrin RBC loses part of membrane as it passes through the spleen spherocytes (SA:V ratio)
Clinical Features Asymptomatic Cardinal features of
o Anaemia (mild: 9-11g/dL)o Jaundiceo Splenomegaly (mild to moderate)
Aplastic crisiso Clinical course may be punctuated by aplastic crises: transient cessation of RBC
productiono Triggered by parvovirus infectionso Because of the shortened lifespan of the RBCs, even a short period of failure of
erythropoiesis results in rapid worsening of anaemiao Self-limited in most caseso May require blood transfusions
Gallstone disease
Investigations FBC: anaemia PBF: spherocytes Pseudohyperkalaemia: K
+leakage as blood is cooled
osmotic fragility
Management No treatment available
When they present, we need to prevent complications of haemoglobinuria by hydratingpatient and encouraging diuresis.
Give folate supplements. Cholecystectomy may be needed in patients with gallstone disease. If patient requires cholecystectomy, perform splenectomy at same sitting for convenience. Splenectomy is beneficial because the major site of destruction is removed.
Administer vaccination against meningococcus, pneumococcus and Hib and possible
case 6 post Splenectomy changes
PBF:
- Cell membrane abnormalities- target cells seen morphology on film
- Howell-jolly bodies (purplish blue inclusion seen in RBC)
- Falciparum: ring forms (early trophozoites), gametocytes
Determine severity of parasitemia
- 20% medical emergency
- 40% fatal
Determine resistance to medication
complications
Manifestation Features
Initial World Health Organization criteria from 1990 [3]
1. Cerebral malaria: Unarousable coma not attributable to any other cause, with a
Glasgow Coma Scale score ≤9; Coma should persist for at least 30min after a generalized convulsion
2. Severe anemia Hematocrit <15% or hemoglobin < 50 g/l in the presence of parasite count >10000/µl
3. Renal failure Urine output <400 ml/24 hours in adults (<12 ml/kg/24 hours inchildren) and a serum creatinine >265 µmol/l (> 3.0 mg/dl)
despite adequate volume repletion
4. Metabolic (Lactic)
Acidosis/acidosis Metabolic acidosis is defined by an arterial blood pH of <7.35 with
a plasma bicarbonate concentration of <22 mmol/L;hyperlactatemia is defined as a plasma lactate concentration of 2-5 mmol/L and lactic acidosis is characterized by a pH <7.25 and a
Breathlessness, bilateral crackles, and other features of pulmonaryoedema. The acute lung injury score is calculated on the basis of radiographic densities, severity of hypoxemia, and positive end-expiratory pressure
6. Hypoglycemia Whole blood glucose concentration of less than 2.2 mmol/l (less
than 40 mg/dl).
7. Hypotension andshock (algid malaria)
Systolic blood pressure <50 mmHg in children 1-5 years or <70mm Hg in patients ≥5 years; cold and clammy skin or a core -skin
temperature difference >100C
8. Abnormal bleeding
and/or disseminatedintavascular
Spontaneous bleeding from the gums, nose, gastrointestinal tract,
retinal haemorrhages and/or laboratory evidence of disseminatedintravascular coagulation.
10. Haemoglobinuria Macroscopic black, brown or red urine; not associated with effects
of oxidant drugs or enzyme defects (like G6PD deficiency) Added World Health Organization criteria from 2000 [4]
11. Impairedconsciousness
Various levels of impairment may indicate severe infectionalthough not falling into the definition of cerebral malaria. Thesepatients are generally arousable
12. Prostration Extreme weakness, needs support
13. Hyperparasitemia 5% parasitized erythrocytes or > 250 000 parasites/µl (in
nonimmune individuals)
14. Hyperpyrexia Core body temperature above 400C
15. Jaundice
(Hyperbilirubinemia)
Serum bilirubin of more than 43m mol/l (2.5 mg/dl).
Other
16. Fluid andelectrolyte
disturbances [5]
Dehydration, postural hypotension, clinical evidence of hypovolemia
17. Vomiting of oraldrugs
Patients with persistent vomiting may have to be admitted forparenteral therapy.
Leukocyte count >12,000/cumm; high CSF lactate (>6mmol/l)and low CSF glucose; more than 3-fold elevation of serum
enzymes (aminotransferases); increased plasma 5'-nucleotidase;low antithrombin III levels; peripheral schizontemia;
papilloedema/retinal oedema
20. MalarialRetinopathy
A large, prospective autopsy study of children dying with cerebralmalaria in Malawi found malarial retinopathy to be a betterindicator of malarial coma. Similar retinopathy in an adult has alsobeen reported.
symptoms : erythromelalgia - a rare neurovascular peripheral pain disorder in which
blood vessels, usually in the lower extremities (or hands), are episodically blocked(frequently on and off daily), then become hyperemic and inflamed. There is severe
burning pain (in the small fiber sensory nerves) and skin redness. The attacks are
periodic and are commonly triggered by heat, pressure, mild activity, exertion,
insomnia or stress. Erythromelalgia may occur either as a primary or secondary
disorder (i.e. a disorder in and of itself or a symptom of another condition). Secondary
erythromelalgia can result from small fiber peripheral neuropathy of any cause,
essential thrombocytosis, hypercholesterolemia, mushroom or mercury poisoning, and
MPD - Myelofibrosis Myelofibrosis (MF) is a chronic bone marrow disorder in which excessive scar
tissue forms in the bone marrow and impairs its ability to produce normal blood cells. MF is thought to becaused by abnormal blood stem cells in the bone marrow. The abnormal stem cells produce more maturecells that grow quickly and take over the bone marrow, causing both fibrosis (scar tissue formation) andchronic inflammation. As a result, the bone marrow becomes less able to create normal blood cells andblood cell production may move to the spleen, causing enlargement, or to other areas of the body.
- Production of cytokines which causes fibrosis of marrow- Proliferation of an abnormal type of bone marrow stem cell results in fibrosis, or
replacement of the marrow with collagenous connective tissue fibers
