1 Flashcards
1
Q
Why is it necessary to wash red cell with NSS for three times?
A
To remove serum/plasma which may contain proteins that may affect the results. Also, through washing, it removes fibrinogen to avoid clots.
2
Q
Why is a Pasteur pipette used in delivering 0.1 ml of washed packed red blood cells instead of a serological pipette?
A
Pasteur pipette was used to avoid clogging if pipette used has a small bore and will affect the fixed volume.
3
Q
What is the important of preparing a red cell suspension in the laboratory?
A
Red cell suspensions provide the appropriate serum to cell ratio to allow for grading and interpretation of tests results.
4
Q
Amount of washed RBC formula
A
Total volume x desired %
5
Q
Total volume
A
prbc/desired %
6
Q
Desired %
A
prbc/TV x 100
7
Q
NSS
A
TV-prbc
8
Q
Differentiate agglutination from hemolysis
A
Hemolysis is the lysis of RBC w/ liberation of Hemoglobin while agglutination, RBC bound to Ab that forms a latticework through Ag Ab bridges.
9
Q
Why is it necessary to observe agglutination reactions microscopically?
A
Because it is the gold standard for sero-diagnosis of leptospirosis because of its unsurpassed diagnostic specificity
10
Q
What is rouleaux formation? What causes it? How do we resolve this problem?
A
Rouleaux formation is formed by RBC stacked like coins. The appearance of rouleaux may be artificially caused by a poor preparation of the smear or by viewing the slide in a thickened area. When rouleaux formation is truly present, it is caused by an increase in cathodal proteins, such as immunoglobulins and fibrinogen.
11
Q
Blood Type A
A
Antigen: A; Antibodies: B; Can receive: O, A; Can Give to: A, AB
12
Q
Blood Type B
A
Antigen: B; Antibodies: A; Can receive: O, B; Can give blood to: B, AB
13
Q
Blood Type AB
A
Antigen: A and B; Antibodies: None; Can Receive: O, A, B, AB; Can Give to: AB
14
Q
Blood Type O
A
Antigen: None; Antibodies: A and B; Can receive: O; Can Give Blood to: O, A, B, AB
15
Q
Interpretation of Forward Blood Grouping:
A
A= + 0 + 0 B= 0 + + 0 AB= + + + 0 O = 0 0 0 0
16
Q
Interpretation of Backward Blood Grouping:
A
A = 0 + + 0 B= + 0 + 0 AB = 0 0 0 0 O= + + + 0
17
Q
What is an antiserum?
A
An antiserum is a reagent source of ABb that is commercially available.
18
Q
What kind of antigen will anti-A detect? Anti-B?
A
Anti- A can detect the antigen while Anti- B can detect the B- antigen present in the blood sample.
19
Q
When is blood typing ordered?
A
ABO groupings and Rh typing are performed on all donated blood. It is also performed when people require blood transfusion.
It is done also on pregnant women to determine compatibility with developing fetus.
For patients who will undergo a transplant.
20
Q
Common causes of false results in ABO Testing
A
False Negative:
- Reagent no added
- Hemolysis
- Undercentrifugation
- Incubation above 20-24 degrees
False Postive:
- Overcentrifugation
- Dirty glassware
- Contaminated reagents
21
Q
What is Rh typing?
A
Used to determine whether you have a specific protein called Rh factor on the outer layer of the RBC.
22
Q
What are the other names of ABO Reverse Typing?
A
Also known as backward typing, indirect typing and serum typing
23
Q
What is the importance of doing serum typing?
A
Serum typing utilizes centrifugation which enhances the reaction of possibly weak Ag/Ab so it can be properly detected.
24
Q
What kind of antibody is found in group “a”? group “B”? group “AB”?
A
Group A has the B antibody
Group B has the A antibody
Group AB has no antibody present
25
What is the difference between ABO Forward Typing from ABO Reverse Typing?
ABO forward typing utilizes whole blood and detects Ag from sample blood by using commercially available antisera. ABO reverse typing utilizes only one serum of the patient and detects antibodies present in the serum sample.
26
Interpretation of H secretor
```
A= + B= 0; Ag present: B,H; Status: B,H secretor
A= 0 B= +; Ag present: A, H; Status: A, H
A= 0 B= 0; Ag present: A,B,H; Status A,B,H
A= + B= +; Ag present: None/H; Status: H secretor
```
27
What is meant by secretor?
A secretor is an individual who is capable of secreting soluble, glycoprotein ABa-soluble substances into saliva and other body fluids.
28
Why must saliva be subjected into increased temperature using a water bath prior to its use?
Saliva is subjected to increased temp in order to inactivate or denature the enzymes present
29
What is the principle involved in this test?
ABH antigens are present in a soluble form n a liquid, they will neutralize their corresponding antibodies and the antibodies will no longer be able to agglutinate red cells possessing the same antigens
30
What is the purpose of diluting the saliva in this test?
Saliva is diluted to prevent zonal secretion during the test
31
Why is saliva preferred as specimen for the determination of blood group soluble substances?
Saliva is the preferred specimen since it is easily collected and readily available
32
Enumerate other sources of the blood group soluble substances
Serum
Sweat
Tears
Semen
33
Types of Blood Donation
Directed: blood is intended for the use of specific patient
Allogenic: blood donation is intended for the use of general patient population
Autologous: blood donated by the owner for future use
Apheresis: takes only the specific component of the blood and the remaining components are returned back to the donor
34
Types of Blood Donor:
Voluntary non-remunerated: donates blood on his own free will without receinving any payment
Professional/ Commercial: donates blood for the sake of money
Family/replacement: allows family and friends to make donations to replace blood that was utilized by you
35
Steps in blood donation
1. Donor recruitment and registration
2. Medical history
3. Physical examination
36
Donor recruitment and registration
- name
- date and time of donation
- address
- gender
- age
- DOB
37
Medical history
ensure the benefit of both donor and recipient
| in a form of questionnaires
38
Physical examination
```
Allogeneic age req. = 17 - 65 years old
Weight: 110 lbs/ 50 kg. - 450 ml of blood: 63 ml anticoagulant
Temperature: 37.5 degrees Celsius
Pulse rate: 50-100 beats per minute
Blood pressure: systolic: 90-160 mmhg
diastolic: 60-100 mmhg
Hemoglobin: autologous: 11 g/dl
allogeneic 12.5 g/dl
Hematocrit: autologous: 33%
allogeneic: 38%
```
39
Serologic Tests
```
ABO/Rh
Antibody screen
HBsAG
Anti-HBc
Anti-HCV
ANTI-HIV 1/2
Anti-HTLV
Syphilis
Malaria
```
40
Deferral
Permanent - high risk history of aids, includes:
a. men sex with men
b. hemophiliacs
c. IV drug abusers
d. sex for money
e. positive for AIDSs
f. viral hepatitis
g. jaundice of unknown origin
h. severe liver, cardiac, lung disease
i. autoimmune disorders
Temporary
For three years: malaria
For one year: Hepa B, rape, tattoo, jail, transfusion, travel areas endemic for malaria, syphilis and gonorrhea, rabies vaccination
For two months: blood donation
For one month: German measles vaccination, isotretinoin, finasteride for prostatic hyperplasia
For six weeks: delivery of baby (AABB) 9 months after child birth
For two weeks: after vaccination with oral polio, measles, mumps or yellow fever
For 48 hours: whole blood donation deferred after hemapheresis
41
Direct Antihuman Globulin Test (DAT)
demonstrate in vivo coating of red cells with antibodies or complement, in particular IgG and C3d ( in vivo sensitization)
42
Antihuman Globulin Test (IAT)
also known as Coomb's test, detects the presence of unexpected antibodies in the patient's serum that are able to coat antigens in type "O" red cells in vitro. It is based on the principle that AHG's obtained from immunized non human species bind to human globulins.
43
What is Coomb's reagent? How is it prepared?
Coomb's reagent is a reagent used in the testing of AHG. It is prepared by an injection of a serum into rabbits to produce antihuman serum.
44
Uses of DAT
detects in vivo sensitization of RBCs with IgG or complement components
45
Uses of IAT
detects incomplete Ab to potential donor RBCs or to screening cells
46
False results in Antihuman Globulin test
```
False +
- improper specimen
- Bacterial contamination
- Polyagglutinate cells
- over reading
- overcentrifugation
False -
- Improper washing
- Interruption testing
- Improper temperature
- Undercentrifugation
```
47
When is DAT performed?
- detect hemolyic disease of newborn
- hemolytic transfusion reaction
- Autoimmune
48
When is IAT performed?
- determination of RBC phenotype using antisera
| - detect incomplete antibody to potential donor RBC
49
Major Crossmatching
- consisting of mixing the patient's serum with donor red cells (PS-DR)
50
Minor Crossmatching
- consisting of mixing the donor's serum with patient red cells (PR-DS)
51
Interpretation of crossmatching
```
1. Protein Phase - 0 0
Thermo Phase - 0 0
AHG Phase - 0 0
Interpretation = Blood is compatible both in major and minor crossmatch. Blood is safe for transfusion.
2. Protein Phase: + 0
Thermo Phase: _ 0
AHG Phase: _ 0
Interpretation = Blood is incompatible in major crossmatch but compatible in minor crossmatch. Blood is not safe for transfusion.
3. Protein Phase: + +
Thermo Phase: _ _
AHG Phase: _ _
Interpretation: Blood is incompatible both in major and minor crossmatch. Blood is not safe for transfusion.
4. Protein Phase: 0 +
Thermo Phase: 0 _
AHG Phase: 0 _
Interpretation: Blood is compatible in major crossmatch but incompatible in minor crossmatch. Blood can be transfused but with caution.
```
52
State the significance of compatibility test in transfusion medicine.
Compatiblity testing is performed to determine if a particular unit of blood can be transfused safely into a certain patient. It is a series of procedure to ensure safety of blood for transfusion.
53
Differentiate major from minor crossmatching.
In major crossmatching recipient serum is used against donor RBC, the minor crossmatch is to test opposite compatibility: donor's plasma/serum agains recipient red cells.
54
What incompatibilities are detected in the:
a. Protein Phase: incompatibilities in the ABO system with hemolysis. May indicate presence of anti-A or anti-B. Caused by cold agglutinins.
b. Thermo Phase: presence of low tittered anti-TH antibody that does not react on immediate spin.
c. Antihuman Globulin Phase: acquired hemolytic anemia will be found in the AHG phase. Antibodies that react in AHG test is called "third order".
55
Whole Blood
1-6 degrees Celsius
ACD, CPD or CP2D = 21 days
CPDA1 = 35 days
56
Packed RBC
1-6 degrees Celsius
ACD, CPD or CP2D = 21 days
CPDA1 = 35 days
Open system when packing = 24 hours
57
Washed RBC
1-6 degrees Celsius
| 24 hours because bag is opened when washing
58
Leukoreduced components/ Leukopoor
```
RBCs
closed system = same
Open system = 24 hours
Platelets
20-24 degrees Celsius = 5 days
```
59
Irradiated blood components
1-6 degrees Celsius
| Original outdate or 28 days from irradiations
60
Neocytes (Young red blood cells)
Same as either Packed RBC or whole blood
61
Random Donor Platelets /Platelet Concentrate
20-24 degrees Celsius for 5 days with constant agitation to prevent aggregation and facilitate gas exchange
Pooled = 4 hours
62
Single Donor Platelet
20-24 degrees Celsius for 5 days with constant agitation to prevent aggregation and facilitate gas exchange
63
Fresh Frozen Plasma
- 18 degrees Celsius = 1 year
| - 65 degrees Celsius = 7 years
64
Cryoprecipitate
Frozen: -18 degrees Celsius = 1 year
Thawed: 20-24 degrees Celsius = 6hrs
Pooled: 20-24 degrees Celsius = 4hours
65
Granulocyte concentrates
20-24 degrees C = 24 hours
66
Allogenic donation guidelines
```
o Age = 16-65 (16-17 with parents consent; 65 above with physicians consent)
o Temperature = 37.50C/99.50F
o Pulse rate = 50-100bpms
o Blood pressure = systolic (90-160) and diastolic (60-100)
o Hemoglobin = at least 12.5 g/dL
o Hematocrit = at least 38%
o Weight = at least 50kg (110lbs)
o General appearance = appears healthy
```
67
Direct anti-human globulin test
is used to demonstrate in vivo coating of red cells with antibodies or complement, in particular IgG and C3d, in other words “in vivo sensitization”.
68
Indirect anti-human globulin test
detects for the presence of unexpected antibodies in the patient’s serum that are able to coat antigens in Type “O” red cells in vitro, in other words “in vitro sensitization”.
69
Blood Bank/Center
A laboratory institution with the capability to recruit and screen blood donors, collect, process, store, transport and issue blood for transfusion and provide information and/or education on blood transmissible diseases
70
Commercial Blood Bank/Center
* A blood bank that exists for profit
| * Not used solely for the operation and maintenance of the blood bank service
71
RA 1517
* AN ACT REGULATING THE COLLECTION, PROCESSING AND SALE OF HUMAN BLOOD, AND THE ESTABLISHMENT AND OPERATION OF BLOOD BANKS AND BLOOD PROCESSING LABORATORIES
* Blood Banking Law of 1956
* June 16, 1956
72
RA 7719
* PROMOTES VOLUNTARY BLOOD DONATION TO PROVIDE SUFFICIENT SUPPLY OF SAFE BLOOD AND TO REGULATE BLOOD BANKS
* National Blood Services Act of 1994
* May 5, 1994
73
CLASSIFICATION BASED ON INSTITUTIONAL CHARACTER:
Hospital Based Blood Bank/Center
| Non-Hospital Based Blood Bank/Center
74
Hospital Based Blood Bank/Center
Located and performing blood bank services within the premises of a hospital
Can perform compatibility testing of blood
75
Non-Hospital Based Blood Bank/Center
Not located and not performing blood bank services within the premises of a hospital
Not part of a hospital
Free standing
76
CATEGORIES OF HOSPITAL BASED BLOOD BANKS
CATEGORY A
• all under category A and B of Non-hospital based
• Compatibility testing
CATEGORY B
• Hospital based BB Category A
• investigation of Transfusion Reaction
• resolution of incompatible cross-matching results
77
Routine tests
```
ABO forward typing
Rh Typing
ABO reverse typing
Antibody Screening
Antibody ID
Antiglobulin test
```
78
Special
Saliva test
Elution test
Adsorption test
Test for detection of HDN and HA
79
No/ of RMTs hired/employed
Category A- at least 4 RMTs
| Category B- at least 5 RMTs
80
Voluntary Non-renumerated Blood Donor
Donates blood of their own free will and receives no money or any form of payment
81
Family or Replacement Blood Donor
Requires to give blood when a member of the patient’s family or community requires it
82
Professional/Paid/Commercial Blood Donor
Donor who gives blood for money or other forms of payment
83
REQUISITES (STAFF)
1. Head
2. RMT
➢ Shifting to cover 24 hrs
➢ at least 1 year on the job training or experience in blood banking services
3. Donor Recruitment officer (at least 1)
➢ MD, RMT, RN
84
PHYSICAL PLANT
1. Workrooms
2. Dust free (air conditioned)
3. Adequate water supply
4. Sufficient space
5. Separate space for bleeding or collection
6. Reception or waiting room for donors
7. Storage Area
85
REAGENTS
* ABO typing sera
* Rh typing sera
* Coomb's rgt
* Copper sulfate
* Giemsa stain
86
BLOOD PRESERVATION
* Primary goal is to provide viable and functional blood components to patients
* 75% of cells are viable 24 hours after transfusion
87
Citrate
Binds to calcium
88
Dextrose
Provides energy to RBC
89
Citric Acid
Lowers pH preventing caramelization
90
Phosphate Buffer
To raise ATP, stabilize pH
91
Adenine
Improve red cell survival
92
ADDITIVE SOLUTION
* Preserving solutions that are added to the RBC after removal of plasma
* Components: SAGM: Saline, Adenine, Glucose and Mannitol (membrane stability)
93
RBC FREEZING
* Primarily used for autologous units and the storage of rare blood types
* Addition of cryoprotective agents to RBCs that are less than 6 days old
* Glycerol-cryoprotective agent
94
Rejuvenation
* Used in some blood centers to regenerate ATP and 2,3 DPG
* Components: PIGPA (Phosphate, Inosine, Glucose, Pyruvate, Adenine)
* Rejuvesol – only FDA approved rejuvenation solution in US
95
BLOOD SUBSTITUTES
* Carry oxygen in the absence of intact RBC
| * e.g. PEG-Hgb (Bovine)
96
BIOCHEMICAL CHANGES OCCURING DURING RED BLOOD CELL STORAGE
```
Decreased:
• pH
• ATP
• 2,3 DPG
• Plasma Sodium
Increased:
• Plasma Hgb
• Plasma K+
• Lactic Acid
```
97
Antigens
a. Also known as Immunogen but strictly speaking, Immunogens are molecules that are foreign to the body thus it would elicit an immune response while Antigens are foreign molecules that enter the body and has a corresponding antibody
b. Elicits an immune response due to it’s:
i. Foreigness
ii. Chemical composition
iii. Molecular size
iv. The ability to be processed by antigen presenting cells (APCs)
c. Only a small part of an antigen called an epitope is recognized by the immune system
98
Immune response (first encounter
a. Immunogen enters body
b. Body recognizes the immunogen as potentially harmful for the body
c. Immune system responds (phagocytosis)
d. Phagocyte digests immunogen and presents the epitope of the immunogen to the T-helper cell
e. T-helper cell presents the epitope of the immunogen to the B-cell activating the B-cell
f. Some activated B-cell becomes memory cells, some B-cells becomes plasma cells
g. Plasma cells produces antibody against the immunogen
h. Immunogen can now be considered as an antigen because it has a corresponding antibody
99
Antibodies
a. Also known as immunoglobins
b. Made up of a basic four-chain polypeptide unit that consists of two large chains called heavy chains or H chains and two smaller chains called light chains or L chains
c. Isotypes: IgG, IgM, IgA, IgD, IgE
i. IgG, IgM – mostly in the serum
ii. IgA – in the serum and body secretions
iii. IgD – B – cells
iv. IgE – Mast cells
100
Antigen-Antibody Reactions
a. Complement - mediated lysis
b. Enhanced Phagocytosis through Opsonization
c. Chemotaxis
d. Inflammatory response
e. Toxin neutralization
f. Antibody dependent cell mediated cytotoxicity
g. Immune complex formation
101
a. Why do we need to prepare an Red Cell Suspension?
To effectively demonstrate antigen and antibody reactions in vitro, like ABO and Rh typing, an immunohematologist must prepare a set up where in there is an optimum ratio between antibodies and antigens.
102
What kind of blood is to be utilized?
Anticoagulated blood – EDTA or 3.2% sodium citrate are acceptable anticoagulants for the preparation of RCS
103
Types of autologous transfusion
a. predeposit of blood by the patient – blood collected is stored as liquid or for longer storage, frozen (blood is reserved for patients anticipating a need for transfusion)
b. inoperative hemodilution – collection of 1-2 units of blood from patient just before the surgical procedure & replacing blood volume by crystalloid or colloid solution; then blood units are infused after surgery
c. inoperative or postoperative blood salvage – the process of removing blood and washing, filtering it prior to reinfusion
104
Emergency transfusion
Immediate infusion of blood to patients who are rapidly or uncontrollably bleeding & cannot wait for crossmatching
• for patient who require immediate transfusion
• Group O RBCs are selected for patients whom transfusion that cannot wait until ABO & Rh type are determined
• Group O-negative RBC units should be used for woman patient of childbearing age
• After issuing O blood or type-specific blood → complete antibody screening & crossmatching
• Patients for surgical procedure → ABO- and Rh-type-specific blood can be given with immediate spin crossmatch
105
Emergency Transfusion Strategies
* Need blood in < 10 mins – give uncrossmatched O neg
* Need blood in 10-30 mins – give uncrossmatched ABO group and Rh type specific
* Need blood in > 30 mins – give crossmatched ABO group and Rh type specific
106
Massive transfusion
the replacement of one or more blood volumes within 24 hours or about 10 units of blood in an adult
107
Neonatal & Pediatric transfusion
infusion of blood to infants (usually premature)
• Premature infants frequently require transfusion of small amounts of blood to replace blood drawn for lab tests
➢ Preferred blood – less than 7 days old
➢ Aliquots – done using satellite or transfer bag
• For very-low-birth-weight infants → blood should be selected to be CMV-seronegative to prevent CMV infection
• Irradiation of blood → recommended to prevent possible GVHD when blood is used for intrauterine transfusion or exchange transfusion
• Infants – who are hypoxic or acidotic → should receive blood tested & negative for hemoglobin S
• infusion of 8-10 mL/kg –increases Hb 3g/dL
108
Storage temperatures
1. Room temp: 200C – 240C
2. Ref temp: 10C – 60C
3. Freezer temp: -180C to -650C
109
Anticoagulant Used:
1. ACD, CPD, CP2D – 21 days
2. CPD-A1 – 35 days
3. Additive Solutions – 42 days
a. Adsol CPD or CP2D +
b. Optisol mannitol
c. Nutricel – CPD or CP2D + citrate & phosphate
110
Response to 1 unit of blood:
Hemoglobin increase of 1 g/dL
| Hematocrit: increase 3%
111
Transportation of Components
1. Temperature for RBCs of 1-100C is required during transport
• Wet ice in plastic bags is placed on top of the blood units to maintain the temp for 24 hrs
2. RBCs are packed in cardboard boxes with a Styrofoam box inside. The ice is double-bagged & weighs approximately 9 lbs.
3. Frozen components are shipped on dry ice. These should be well wrapped because dry ice evaporates and space in the box for movement should be allowed.
4. Platelets are shipped at room temperature (platelets can survive without agitation for a maximum of 24 hours)
5. When component shipments are received, observe & record the temperature and appearance of units.
• All problems & disposition of units must be documented and stored with blood bank records
112
Transfusion reaction
any unfavorable transfusion-related event occurring in a patient during or after transfusion of blood components
• Occur in up to 10% of transfusion recipients
• Majority of life threatening transfusion reactions occur early in the course of the transfusion
• Monitor pt closely during first 15 mins of txn
113
Bacterial Organisms Associated with Transfusion-Associated Sepsis or BACON
```
Gram +:
• Staphylococcus species
• Streptococcus species
• Bacillus species
Gram -:
• Serratia species
• Yersinia species
• Acinetobacter species
• Escherichia species
• Pseudomonas species
• Providencia species
```
114
Errors Associated with Transfusion Reaction
4 leading causes:
a. improper specimen identification
b. improper patient identification
c. antibody identification error
d. crossmatch procedure error
115
MNEMONICS: GOT A BAD UNIT
G - GRAFT VERSUS HOST DISEASE
O - OVERLOAD (IRON, VOLUME)
T - THROMBOCYTOPENIA (POST TRANSFUSION PURPURA)
A - ALLOIMMUNIZATION
B - BLOOD PRESSURE INSTABILITY (ANAPHYLACTIC SHOCK)
A - ACUTE HEMOLYTIC REACTION
D - DELAYED HEMOLYTIC REACTION
U - URTICARIA (ALLERGIC CUTANEOUS)
N - NEUTROPHILIC (FEBRILE)
I - INFECTION (HIV, HEPATITIS, CMV, BACTERIAL SEPSIS)
T - TRANSFUSION RELATED ACUTE LUNG INJURY (TRALI)
116
HIV1/2
agent of AIDS
o a member of the Lentivirus family of retroviruses
o transmitted via sexual contact & exposure to blood products
o best detected by MP-NAT (minipool nucleic acid testing) detects viral ribonucleic acid (RNA) rather than the p24 protein; because the viral RNA appears in blood before p24, an infection can be detected earlier, and the window period is therefore reduced
117
HTLV I/II
RNA retovirus causing a T-cell proliferation with persistent infection
o associated with adult T-cell lymphoma/leukemia
o transmitted vertically (breastfeeding), sexually & parenteral (blood transfusion & IV drug abuse)
o recommended tests: NAT, EIA & PCR
118
Transfusion-Associated Hepatitis
```
o Hepatitis A
o Hepatitis B
o Hepatitis C
o Hepatitis D
o Hepatitis E
o Hepatitis G
```
119
Hepatitis A
– also known as infectious hepatitis
– caused by Hepatitis A virus ( single-stranded RNA enterovirus and a member of the
Picornaviridae family)
– usually transmitted by fecal contamination and oral ingestion
– can be transmitted by transfusion while virus is circulating in the blood (very rare)
120
Hepatitis B
originally known as serum hepatitis caused by Hep B virus
– first known hepatitis transmitted by blood transfusion
• HBV – member of the Hepadnaviridae family, is capable of withstanding extreme temperatures and humidity
• high level in blood, serum & wound exudates
• Moderate levels in semen, vaginal fluids & saliva
• Low levels in urine, feces, sweat, tears & breast milk
• Transmission may be percutaneous or permucosal
• Percutaneous transmission – needle stick (drug use, acupuncture, tattooing, occupational hazard & body piercing), hemodialysis, human bite, transfusion or sharing of razors
• Permucosal transmission – sexual intercourse, transplacental or through breast milk
121
Hepatitis C
caused by Hep C virus (a spherical, enveloped, single-stranded RNA virus
belonging to the Flaviviridae family)
– the leading cause of liver transplants in the US
– formerly known as non-A, non-B hepatitis or posttransfusion hepatitis
• Transmitted precutaneously or permucosally
• NAT – detect HCV RNA
• RIBA – used for confirmation of anti-HCV test
o Hepatitis D – caused by Hep D virus
• HDV – defective, single-stranded RNA virus that is found in patients with HBV infection
o Hepatitis E – caused by Hep E virus (member of Caliciviridae family & has many similarities with HAV)
– common mode of transmission is also feco-oral, but HEV may also be transfusion transmitted
o Hepatitis G
• HAV & HEV – transmitted through fecal/oral route
• HBV, HCV, HDV, HGV – primarily transmitted parenterally
122
West Nile Fever
caused by WNV – member of Flavivirus which is transmitted by mosquito bite
o Mild flu-like disease & is capable of crossing BBB leading to West Nile encephalitis
o NAT – recommended to break transmission of WNV
123
CMV
member of herpes virus causing mononucleosis-like symptoms
• the organism's transmission is prevented by transfusing leukocyte-depleted blood products, which is consistent with the fact that CMV is a leukocyte-associated pathogen.
• major concern when transfused to immunocompromised hosts
124
EBV
member of herpesvirus family causing infectious mononucleosis
125
Parvovirus B19
common cause of childhood illness called “fifth disease”
• Non-enveloped virus that is usually transmitted by the respiratory route and that eventually infects hematopoietic cells
• may also be transmitted vertically from mother to child and via blood products
• transmission by blood products is common because the virus does not have a lipid envelope
• may cause bone marrow failure in immunocompromised patients and patients with sickle cell disease
126
Human Herpesvirus 6
causes rosoela infantum or also known as “sixth disease”
• was the sixth herpesvirus discovered
• now recognized as a T-cell lymphotropic virus with high affinity for CD4 lymphocytes
• infection usually occurs in infants and is the most common cause of fever-induced seizures in children aged 6-24 months
• infection is rare in immunocompetent adults but may manifest as a mononucleosislike illness characterized by fever, lymphadenopathy, and hepatitis or encephalitis, with negative test results for CMV or Epstein-Barr virus (EBV)
127
Human Herpes virus 8
causes Kaposi’s sarcoma & Castleman’s disease
• eighth human herpesvirus
• Kaposi's sarcoma-associated herpesvirus (KSHV) – informal name
• Human cancer virus commonly infecting AIDS patients (ONCOVIRUS)
128
HEMOLYTIC DISEASE OF THE FETUS & NEWBORN (HDFN)
* Maternal IgG antibodies cross placenta and destroy the baby’s rbcs
* RBCs lysed releasing hemoglobin and metabolized to uncomjugated bilirubin
* Fetus becomes anemic due to rbc destruction → cardiac failure or hydrop fetalis
* Bilirubin accumulates in the baby (immature liver)
* Build-up of bilirubin → jaundice & cause deafness, mental retardation, kernicterus (accumulation of bilirubin to the brain) & even death
129
Types of HDN
1. Mild – ABO HDN
| 2. Severe – RH HDN
130
Mild – ABO HDN
* Most common form of HDN (A & B babies born to O mother)
* Usually not treated by transfusion
* Infants are treated by phototherapy (breakdown of excess bilirubin)
* May require transfusion weeks or months after birth in rare cases
131
Severe - RH HDN
* D-negative mother develops antibodies during the first pregnancy with d-positive baby or after transfusion with d-positive RBCs. The mother’s anti-D attack the fetus of subsequent pregnancies if baby’s rbcs are D-positive
* Exchange transfusion may be needed to prevent kernicterus
* Lab tests on newborn: Positive DAT & increased serum bilirubin
* Administration of RhIG
* May be caused by other IgG antibodies of the Kell, Kidd, Duffy, & other systems
132
Diagnosis of HDFN
1. DAT
2. Serum bilirubin determination
3. Amniocentesis – Liley’s method (bilirubin absorbance)
4. Antibody screening on mother
133
Prevention of HDFN
1. Prenatal Rh Immune Globulin (RhIG)
2. Postpartum administration
3. Fetal Screen (Rosette test)
4. Kleihauer-Betke Acid Elution test
134
ABO gene locus
located in chromosome 9q34 and encodes the A and B glycosyltransferases
135
Most mutations are located within?
Exon 7
136
ABO antibodies are weak or absent
In the sera of newborns until 3 to 6 months of age
137
Adult levels of ABO antibodies are reached by
5 to 10 years of age
138
Plasmodium falciparum
bind A and B antigens with rosette formation, a possible risk of cerebral malaria
139
GYPA (CD235A)
a major RBC membrane glycoprotein
140
MNS blood group system
second blood group system identified after ABO
