34. Non-regenerative anaemias Flashcards
Non- Regenerative Anaemias?
Anaemias with a lack of regenerative response (whereby new RBC
production is insufficient for the demand)
Normal reticulocyte (immature RBCs) count:
§ Dog: 60-80 x 109 cells/l
§ Cat: 15-42 x 109 cells/l
During blood loss, this number should be ~3× higher
During haemolysis, this number should be ~7× higher
Polychromasia: When there is an ↑ of intensely stained (likely
immature) RBCs
It takes ~4 days for RBCs to mature, so this is the length of time
needed for the bone marrow to respond to the anaemia
Causes of Non- Regenerative Anaemias?
Causes Of Non-Regenerative Anaemias
DRUGS/TOXINS
Chemotherapy:
§ 5 days of neutropenia
§ 2 weeks of thrombocytopenia
§ ~1 month of anaemia
§ Damage is often reversible
Oestrogen:
§ Dose-dependent; Poor prognosis
§ Either exogenous or endogenous (neoplasia)
Other drugs:
§ Anti-inflammatories: Phenylbutazone
§ Antibiotics: Trimethoprim
§ Anticonvulsants: Phenobarbital
§ Antiparasitics: Fenbendazole
PATHOGENS
§ Parvovirus § Histoplasma spp.
§ Rickettsia spp. § Leishmania spp.
§ Ehrlicia canis § Cryptococcus spp.
§ FIV § Feline panleukopenia
PRIMARY BM SUPRESSION
§ Pure red cell aplasia (reticulocyte precursor destruction)
§ Aplastic anaemia (hypoplastic BM replaced by fat)
§ BM necrosis; BM fibrosis
§ BM tumour
Non- Regenerative Anaemia Diseases?
Non-Regenerative Anaemia Diseases
PURE RED CELL APLASIA
Immune mediated intravascular peracute haemolysis (nonregenerative immune mediated haemolytic anaemia)
If it remains non-regenerative for >5 days, the immune system is
targeting erythroid precursor cells in the BM
Predisposed: Young/middle-aged; Neutered females
Diagnosis → BM biopsy:
§ Dysmyelopoesis § Fibrosis
§ Haemorrhage § Necrosis
Treatment: See “Immune mediated haemolytic anaemia” in topic 32
Deficiency Anaemias/ Refractory Anaemias?
DEFICIENCY ANAEMIAS / REFRACTORY ANAEMIAS
Anaemias not related to the bone marrow
Iron deficiency anaemia
§ Chronic blood loss
§ Blood sucking parasites
§ Chronic GI bleeding (ulcer; tumour)
§ Chronic cystitis
Vitamin B12 deficiency
Anaemia perniciosa
§ Chronic GIT disease → IBD
§ EPI
§ Hereditary receptor defect: Giant Schnauzer; Beagle
Chronic kidney disease → Erythropoietin loss
Erythropoietin is produced in the renal cortex
§ Treatment: Recombinant human erythropoietin & iron
§ During end-stage kidney failure, azotaemia may have an
additional detrimental effect to the RBCs, worsening the
animal’s condition
Anaemia of chronic disease?
ANAEMIA OF CHRONIC DISEASE
Lack of hormones
§ Hypothyroidism (diagnose with T4/TSH)
§ Addison’s disease (diagnose with ACTH-stim.)
Portosystemic shunt
Inflammation → Cytokine release → ↑ Hepcidin release → ↓
Ferritin → ↓ Fe availability
Causes:
§ Chronic inflammatory disease (IBD)
§ Acute inflammatory disease (pyometra; sepsis)
§ Chronic kidney disease
§ Neoplasia
Diagnosis: ↓ Fe; ↓Fe-binding capacity; ↑ CRP (C-reactive
protein)
Myelodysplastic syndromes?
MYELODYSPLASTIC SYNDROMES
Group of cancers; Immature RBCs fail to mature
Clinical signs: Weakness; Exercise intolerance; Fever; Haemorrhage
Lab. D: Non-regenerative; Panleukopenia; Thrombocytopaenia
Diagnosis: BM biopsy → Dyserythropoesis; ↑ Myeloblasts
Acute Lymphoblastic Anaemia?
ACUTE LYMPHOBLASTIC ANAEMIA
Proliferation of immature lymphoblasts
Predisposed: Middle/old-aged > Young
Clinical signs
§ Lethargy
§ Weight loss
§ Intermittent fever
§ Hepatosplenomegaly
§ Abdominal pain
Lab. D: Anaemia; Leukopenia; Ø Lymphoblasts in peripheral blood
Diagnosis: BM biopsy → Lymphoblast proliferation (30%
lymphoblasts)
Differential diagnosis: Lymphoma stage V
Chronic Lymphoblastic anaemia?
CHRONIC LYMPHOBLASTIC ANAEMIA
Proliferation of mature lymphocytes (CD8 & T-cells)
Predisposed: Old > Young
Clinical signs
§ Hepatosplenomegaly § Fever
§ Intermittent lameness § PU/PD
§ Mild lymphadenomegaly § Haemorrhages
Lab. D: Normocytic, normochromic non-regenerative anaemia;
Lymphocytosis; Neutropenia
Treatment: Prednisolone + Chlorambucil
Treatment of non-regenerative anaemia
§ Treat the underlying cause
§ Blood transfusion
§ Anaemia: Give packed red blood cells
§ Thrombocytopaenia: Fresh whole blood;
Packed RBCs + Platelet rich plasma
