54 Hemolytic Anemia resulting from Infections with Miroorganisms

Question 1

Mechanisms that may lead to hemolysis during infections

Direct invasion of or injury

Answer 1

Malaria, babesiosis, and bartonellosis

Question 2

Mechanisms that may lead to hemolysis during infections

Elaboration of hemolytic toxins

Answer 2

Clostridium perfringens

Question 3

The world’s most common cause of hemolytic anemia

Answer 3

Malaria

Question 4

Specialized invasion proteins that invade in Malaria

Answer 4

Erythrocyte binding-like (EBA) and reticulocyte homology (RH) protein families

Bind to receptors on the erythrocyte surface, including glycophorins A/B/C, CR1 (CD35), and basigin (CD147)

Question 5

Erythrocytes infected with Plasmodium falciparum develop surface knobs that contain receptors, especially the P. falciparum erythrocyte membrane protein-1 (PfEMP-1) for endothelial proteins.

All parasites bind to ________ and___________ found on endothelial surfaces

Answer 5

CD36 antigen (platelet glycoprotein IV)
Thrombospondin

Some bind to the intercellular adhesion molecule-1 (ICAM-1), and a few bind to the vascular cell adhesion molecule (VCAM)

Question 6

TRUE OR FALSE

The anemia of falciparum malaria is characteristically a normocytic-normochromic anemia with a paucity of reticulocytes. If microcytosis is present, the concomitant presence of α- or β-thalassemia or iron deficiency should be considered.

Answer 6

TRUE

The anemia of falciparum malaria is characteristically a normocytic-normochromic anemia with a paucity of reticulocytes.

If microcytosis is present, the concomitant presence of α- or β-thalassemia or iron deficiency should be considered.

Question 7

Disease conditions that interfere with invasion of erythrocytes by parasites (malaria) and their proliferation

Resistance to malaria

Answer 7

G6PD deficiency, Southeast Asian ovalocytosis , CR1 deficiency, the thalassemias, sickle cell anemia, and other hemoglobinopathies

Question 8

Plasmodial species that are notably associated with hemolytic anemia

Answer 8

P. falciparum, P. vivax

Question 9

Plasmodial specie that invades only young red cells

Answer 9

P. vivax

Question 10

Plasmodial specie that attacks both young and old cells, more severe and is the most deadly type

Answer 10

P. falciparum

Question 11

The only plasmodium that infects humans that is zoonotic

It is not transmitted from human to human by a mosquito vector

Causes severe malaria with a frequency similar to P. falciparum, and this includes a high frequency of intravascular hemolysis

Answer 11

P. knowlesi

Question 12

TRUE OR FALSE

Plasmodium falciparum also decreases the erythropoietin response

Answer 12

TRUE

Plasmodium falciparum also decreases the erythropoietin response

Resulting in less erythropoiesis than expected for the degree of anemia, reticulocytopenia, and, coincidentally, striking dyserythropoiesis with red cell stippling, cytoplasmic vacuolization, nuclear fragmentation and multinuclearity

Question 13

Intravascular hemolysis in ________ malaria may be more frequent than in any other type of malaria.

Answer 13

P. knowlesi

Question 14

The fever associated with malaria, accompanied by rigors, headache, abdominal pain, nausea and vomiting, and extreme fatigue, is characteristically cyclic, varying in frequency according to the malaria type.

Answer 14

BLACKWATER FEVER

Question 15

Febrile paroxysms of malaria

P. vivax:
P. malariae:
P. falciparum:

Answer 15

P. vivax: every 48 hours
P. malariae: every 72 hours
P. falciparum: daily

Question 16

Mechanism of periodic fever in malaria

Answer 16

Schizont rupture

Question 17

Considered the standard of diagnosis in Malaria

Answer 17

Identification of the malarial parasite on the blood film

Involves examination of a thick and thin blood film preparation

In nonimmune patients, examination of the blood film for malarial parasites should be made for at least 3 days after onset of symptoms because parasitemia may not reach detectable levels for several days.

Question 18

Alternative and supplementary technique used to demonstrate the appropriate DNA sequences in the blood or the use of automated hematology analyzers to identify parasites as part of a routine complete blood count investigation.

Answer 18

Polymerase chain reaction (PCR)

Question 19

If more than____% of the red cells infected contain parasites, the infection is almost certainly with P. falciparum.

Answer 19

5%

Question 20

This finding is regarded as pathognomonic of P. falciparum

Answer 20

The finding of two or more rings within the same red cells

Question 21

Approximately 15% of the cases were severe as indicated by one or more of the following:

Answer 21

• Hemoglobin less than 70 g/L
• Parasitemia of greater than 5% of red cells
• Acute renal injury
• Acute respiratory distress syndrome
• Jaundice and requiring rapid treatment and intensive care

Question 22

Other names for Bartonellosis

Answer 22

Oroya Fever
Carrión disease

Question 23

Human bartonellosis is transmitted by

Answer 23

Sand fly (Lutzomyia spp)

The only reservoir for this organisms is human beings.

Question 24

Mechanism of Bartonellosis

Answer 24

Red cells are rapidly removed from the circulation, apparently both by liver and spleen.

The organism does not grow within the red cell but rather adheres to its exterior surface

The osmotic fragility of the red cells is normal.

Di sira yung cell; nskadikit lang

Question 25

Bartonella protein that causes erythrocytes to acquire **trenches, indentations, and invaginations** has been purified from culture broths and has been called

Answer 25

Deformin

Question 26

Two B. bacilliformis genes that encode for this protein that greatly **enhance the ability of Escherichia coli to invade erythrocytes**

Answer 26

Invasion-associated locus proteins A and B, designated ialA and ialB

Question 27

Represents the *early, invasive stage* of a chronic granulomatous disorder of Bartonellosis

Answer 27

Oroya fever

Question 28

The second stage of B. bacilliformis infection characterized by a skin eruption of **cutaneous vascular nodular tumors (hemangioma-like)** often on the **face and extremities**

Answer 28

Verruca peruviana (also called verruca peruana) ## Footnote ***Immunosuppression** is an accompaniment of B. bacilliformis infection, leading to **secondary infections**, exemplified by staphylococcal and Salmonella bacteremia or Toxoplasma bacteremia and myocarditis.*

Question 29

Diagnosis of Bartonellosis is established by

Answer 29

Demonstrating the presence of the organism on the erythrocytes Giemsa-stained blood films reveal red-violet rods varying in length from 1 to 3 μm and in width from 0.25 to 0.2 μm.

Question 30

Treatment for patients with Oroya fever

Answer 30

Aminoglycosides, cephalosporins, macrolides, quinolones, penicillins, tetracyclines, and others (eg, rifampin)

Question 31

Babesiae are intraerythrocytic protozoa known as

Answer 31

Piroplasms

Question 32

Babesiosis is transmitted by the bite of

Answer 32

Tick:Ixodes scapularis

Question 33

Babesiae species that infect humans

Answer 33

Babesia microti, Babesia divergens, Babesia duncani, and Babesia venatorum

Question 34

Cases of babesiosis transmitted by **transfusion** are mostly caused by

Answer 34

Mostly caused by **Babesia microti** but also by **Babesia duncani**

Question 35

Morphology of Babesia in thin blood films

Answer 35

**Darkly stained ring forms with light blue cytoplasm** **Maltese cross tetrad:** consists of four daughter cells of Babesia connected by cytoplasmic bridges

Question 36

Test of choice for confirmation of an active infection in an individual bearing antibodies to Babesia and for following the response to therapy

Answer 36

Immunofluorescent tests for antibodies to Babesia and PCR-based diagnostic tests

Question 37

# TRUE OR FALSE Most mild B. microti infections respond without treatment.

Answer 37

TRUE Most mild B. microti infections respond **without** treatment.

Question 38

Treatment for Babesiosis

Answer 38

Clindamycin and quinine Atovaquone and azithromycin Tafenoquine

Question 39

Treatment for **recalcitrant** cases of Babesiosis

Answer 39

Whole-blood or red cell exchange

Question 40

Infection that most likely to occur in patients who have undergone septic abortion, after acute cholecystitis, as a result of an intrahepatic abscess, and, rarely, after amniocentesis (amnionitis)

Answer 40

Clostridium perfringens (formerly Clostridium welchii)

Question 41

Are gram-positive, encapsulated, spore-forming, anaerobic bacilli Causes **gas gangrene** in soft tissues

Answer 41

Clostridium perfringens (formerly Clostridium welchii)

Question 42

Toxin that is the agent that causes **intravascular hemolysis** in Clostridium perfringens septicimeia

Answer 42

Lysolecithins ## Footnote The **α-toxin** of C. perfringens is a **lecithinase C** that reacts with lipoprotein complexes at cell surfaces, liberating potent hemolytic substances, lysolecithins.

Question 43

# TRUE OR FALSE The lysis of red cells (decreasing packed red cell volume) and the high plasma hemoglobin can produce a marked dissociation between the blood hemoglobin and hematocrit level.

Answer 43

TRUE The **lysis of red cells** (decreasing packed red cell volume) and the **high plasma hemoglobin** can produce a ***marked dissociation between the blood hemoglobin and hematocrit level***. ## Footnote For example, hematocrits approaching zero with blood hemoglobins as high as 8 g/dL can occur.

Question 44

Therapy for Clostridium perfringens septicimeia

Answer 44

Antibiotic therapy, fluid support, red cell transfusion, and when appropriate surgical debridement

Question 45

Pathogens that produce **red cell agglutination** in vitro

Answer 45

Haemophilus influenzae, E. coli, and Salmonella spp.

Question 46

Microorganisms may play a role in precipitating **autoimmune hemolytic disease**

Answer 46

Mycoplasma pneumoniae, measles, cytomegalovirus, varicella, herpes simplex, influenzas A and B, Epstein-Barr, human immunodeficiency virus, and coxsackievirus

Question 47

Microangiopathic hemolytic anemia may be triggered by a variety of infections:

Answer 47

Shiga toxin-producing E. coli, Shigella dysenteriae type 1, Campylobacter spp., and Aspergillus spp.