Page 403 - Essential Haematology

Chapter 28 Haematological changes in systemic disease / 389

Table 28.5 Blood abnormalities associated with infections.
Haematological abnormality Infection associated
Anaemia
Anaemia of chronic disorders Chronic infections especially tuberculosis
Aplastic anaemia Viral hepatitis
Transient red cell aplasia Human parvovirus
Marrow fi brosis Tuberculosis
Immune haemolytic anaemia Infectious mononucleosis, Mycoplasma
pneumoniae
Direct red cell damage or microangiopathic Bacterial septicaemia (associated DIC),
Clostridium perfringens , malaria, bartonellosis
Viruses – haemolytic uraemic syndrome and TTP
Hypersplenism Chronic malaria, tropical splenomegaly
syndrome, leishmaniasis, schistosomiasis
White cell changes
Neutrophil leucocytosis Acute bacterial infections
Leukaemoid reactions Severe bacterial infections particularly in infants
Tuberculosis
Eosinophilia Parasitic diseases (e.g. hookworm, fi lariasis,
schistosomiasis, trichinosis)
Recovery from acute infections
Monocytosis Chronic bacterial infections: tuberculosis,
brucellosis, bacterial endocarditis, typhoid
Neutropenia Viral infections – HIV, hepatitis, infl uenza
Fulminant bacterial infections (e.g. typhoid,
miliary tuberculosis)
Lymphocytosis Infectious mononucleosis, toxoplasmosis,
cytomegalovirus, rubella, viral hepatitis,
pertussis, tuberculosis, brucellosis
Lymphopenia HIV infection
Legionella pneumophila
Thrombocytopenia
Megakaryocytic depression, immune complex - Acute viral infections particularly in children (e.g.
mediated and direct interaction with platelets measles, varicella, rubella, malaria, severe
bacterial infection)
Prothrombotic state All with prolonged infl ammation

DIC, disseminated intravascular coagulation; HIV, human immunodefi ciency virus; TTP, thrombotic thrombocytopenic
purpura.

with certain infections (e.g. bacterial meningitis). red cells (Fig. 28.6 ). Haemolysis in bartonellosis

The acute phase response to infections is accompa- (Oroya fever) is caused by direct red cell infection.
nied by a rise in coagulation factors and a fall in With severe acute bacterial infections there may be
natural anticoagulants. thrombocytopenia. Mycoplasma pneumoniae infec-
Clostridium perfringens organisms produce an α tions are associated with autoimmune haemolytic
toxin, a lecithinase acting directly on the circulating anaemia of the ‘ cold ’ type (see p. 84 ).