Immunology ASCP MLT medialab
UPDATED ACTUAL Exam Questions and
CORRECT Answers
The prozone effect can be described by all of the following EXCEPT:
- Results in a false negative reaction
- The result of antibody excess
- Dilution of antibody can help prevent its occurrence
- Results in a false positive reaction - CORRECT ANSWER - - Results in a false positive
reaction
Prozone is the result of antibody excess--where the concentration of antibody exceeds the
concentration of antigen; it appears as a false negative, which can become positive as the
patient's serum is diluted.
It does not yeild a false positive reaction.
Suppose a patient with stiffness in her fingers has a positive antinuclear antibody (ANA) test
with a centromere pattern at a 1:1280 titer. What is the most likely diagnosis?
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis
- Sjogren's syndrome
- CREST syndrome - CORRECT ANSWER - - CREST syndrome
Centromere antibodies are present in over half of patients with the CREST syndrome, an
acronym named after the major features of this autoimmune disorder: calcinocis, Raynaud's
phenomenon, esophageal dysmotility, sclerodactyly, and telangiesctasia. While the ANA result
alone is not diagnostic, this patient is having clinical symptoms of stiff fingers that fits nicely
with the centromere ANA pattern.
In Systemic lupus erythematosus (SLE), the ANA pattern is usually homogeneous or speckled;
in rheumatoid arthitis and Sjogren's syndrome, it is usually specked.
,Hyperacute rejection of a transplanted organ is caused by:
- Pre-formed humoral antibodies in a patient
- Patient sensitization to donor antigens
- Development of allogeneic reaction to donor antigens
- Disturbance of host-graft tolerance - CORRECT ANSWER - - Pre-formed humoral
antibodies in a patient
The presence of pre-formed humoral antibodies in a patient reacting with donor tissue cellular
antigens is the entire cause of hyperacute rejection. The preformed antibodies are usually anti-A
or anti-B related antibodies to the ABO system or antibodies to class I MHC antigens
(hypersensitivity type II).
Previous patient sensitization to donor antigens is a T cell-mediated cause of accelerated
rejection of graft rejection in kidney grafts. It is comparable to the second-set rejection
phenomenon observed in animal models of graft rejection.
The development of an allogeneic reaction to donor antigens is the cause of acute rejection. This
type of rejection can result after the first exposure to antigens. Although the early process of
rejection, equivalent to a first-set allograft rejection in experimental animals, is mediated by T
cells, later rejection may involve antibodies and complement, possibly antibody cell-mediated
cytotoxicity).
Disturbance of host-graft tolerance, chronic graft rejection, is a cell-mediated process that
develops later than 3 months after transplantation. Chronic rejection occurs in most graft
recipients. The process produces a slow but continual loss of organ function.
Diseases associated with a dysfunction of polymorphonuclear neutrophils (PMNs) include all of
the following with the exception of:
- Chediak-Higashi syndrome (CH)
- Chronic granulomatous diseases (CGDs)
- Gaucher 's Disease
- Myeloperoxidase deficiency (MPO) - CORRECT ANSWER - - Gaucher 's Disease
Gaucher's disease is a monocyte-macrophage disorder caused by a rare genetic defect. There is a
high incidence of this disease in Ashkenazi Jews. There are two types of the disease:
neuronopathic and nonneuronopathic, depending on symptoms. The disorder represents a
deficiency of B-glucocerebrosidase, the enzyme that normally splits glucose from its parent
,sphingolipid, glucosylceramide. As a result of this enzyme deficiency, cerebroside accumulates
in histiocytes (macrophages). Gaucher cells, typically a large cell with one to three eccentric
nuclei and a characteristically wrinkled cytoplasm, are found in the bone marrow, spleen, and
other organs of the mononuclear phagocyte system. Gaucher cells are rarely seen in the
circulating blood.
Chediak-Higashi syndrome is a congenital neutrophil abnormality. Because of an abnormal
granulation of neutrophils, it results in a qualitative neutrophil disorder of neutrophils. The
neutrophils with giant granules display impaired chemotaxis and delayed killing of ingested
bacteria.
Chronic granulomatous diseases(CGDs) are congenital neutrophil abnormalities. They are a
genetically heterogeneous group of disorders of oxidative metabolism affecting the cascade of
events required for H2O2 production by phagocytes during phagocytosis. Life-threatening
infections can result. Patients with autosomal-recessive form may have a less severe clinical
course than patients with X-linked forms of CGD
Myeloperoxidase deficiency is a congenital neutrophil abnormality. Myeloperoxidase is an iron-
containing heme protein responsible for the peroxidase activity characteristic of azurophilic
granules in neutrophils. Human neutrophils contain many granules of various sizes that are
morphologically, biochemically, and functionally distinct. The azurophilic granules normally
contain
The term TITER (as it applies to the measurement of antibodies) is best defined as:
- Concentration of antibody in the serum
- Maximum reactive dilution X 100
- Maximum reactive dilution / 100
- Reciprocal of maximum reactive dilution - CORRECT ANSWER - - Reciprocal of
maximum reactive dilution
The term TITER (as it applies to the measurement of antibodies) is best defined as reciprocal of
maximum reactive dilution of the patient's serum where the antibody is still detectable. For
example, a specimen with a last reacting tube containing a 1:100 dilution, would be said to have
a titer of 100.
Which of the following types of molecules is most likely to be antigenic/immunogenic?
- Nucleic acids
- Carbohydrates
, - Lipids
- Proteins - CORRECT ANSWER - - Proteins
Proteins are complex molecules with a high molecular weight and are more antigenic than the
other types of molecules.
Carbohydrates are the second most antigenic molecules.
Lipids are the third antigenic molecules from this list.
Nucleic acids are not generally antigenic.
A physician suspects his patient might have rheumatoid arthritis. Which of the following markers
should be ordered?
- Antimitochondrial antibodies
- Anti-IgG
- Antineutrophilic antibodies
- Antimyocardial antibodies - CORRECT ANSWER - - Anti-IgG
Rheumatoid arthritis commonly presents with an increase of IgM antibodies that are directed
toward the Fc portion of IgG. These anti-IgG antibodies are called rheumatoid factor (RF).
Patients with primary biliary cirrhosis will have an increase in antimitochondrial antibodies.
Wegener's granulomatosis presents with antineutrophilic antibodies.
Antimyocardial antibodies are important markers in patients who have rheumatic fever.
Flow cytometry is a useful tool in the study all of the following disorders, EXCEPT?
- HIV
- Leukemia
- Viral hepatitis
- Lymphoma - CORRECT ANSWER - - Viral hepatitis
Viral hepatitis is diagnosed primarily by ELISA or molecular techniques.
UPDATED ACTUAL Exam Questions and
CORRECT Answers
The prozone effect can be described by all of the following EXCEPT:
- Results in a false negative reaction
- The result of antibody excess
- Dilution of antibody can help prevent its occurrence
- Results in a false positive reaction - CORRECT ANSWER - - Results in a false positive
reaction
Prozone is the result of antibody excess--where the concentration of antibody exceeds the
concentration of antigen; it appears as a false negative, which can become positive as the
patient's serum is diluted.
It does not yeild a false positive reaction.
Suppose a patient with stiffness in her fingers has a positive antinuclear antibody (ANA) test
with a centromere pattern at a 1:1280 titer. What is the most likely diagnosis?
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis
- Sjogren's syndrome
- CREST syndrome - CORRECT ANSWER - - CREST syndrome
Centromere antibodies are present in over half of patients with the CREST syndrome, an
acronym named after the major features of this autoimmune disorder: calcinocis, Raynaud's
phenomenon, esophageal dysmotility, sclerodactyly, and telangiesctasia. While the ANA result
alone is not diagnostic, this patient is having clinical symptoms of stiff fingers that fits nicely
with the centromere ANA pattern.
In Systemic lupus erythematosus (SLE), the ANA pattern is usually homogeneous or speckled;
in rheumatoid arthitis and Sjogren's syndrome, it is usually specked.
,Hyperacute rejection of a transplanted organ is caused by:
- Pre-formed humoral antibodies in a patient
- Patient sensitization to donor antigens
- Development of allogeneic reaction to donor antigens
- Disturbance of host-graft tolerance - CORRECT ANSWER - - Pre-formed humoral
antibodies in a patient
The presence of pre-formed humoral antibodies in a patient reacting with donor tissue cellular
antigens is the entire cause of hyperacute rejection. The preformed antibodies are usually anti-A
or anti-B related antibodies to the ABO system or antibodies to class I MHC antigens
(hypersensitivity type II).
Previous patient sensitization to donor antigens is a T cell-mediated cause of accelerated
rejection of graft rejection in kidney grafts. It is comparable to the second-set rejection
phenomenon observed in animal models of graft rejection.
The development of an allogeneic reaction to donor antigens is the cause of acute rejection. This
type of rejection can result after the first exposure to antigens. Although the early process of
rejection, equivalent to a first-set allograft rejection in experimental animals, is mediated by T
cells, later rejection may involve antibodies and complement, possibly antibody cell-mediated
cytotoxicity).
Disturbance of host-graft tolerance, chronic graft rejection, is a cell-mediated process that
develops later than 3 months after transplantation. Chronic rejection occurs in most graft
recipients. The process produces a slow but continual loss of organ function.
Diseases associated with a dysfunction of polymorphonuclear neutrophils (PMNs) include all of
the following with the exception of:
- Chediak-Higashi syndrome (CH)
- Chronic granulomatous diseases (CGDs)
- Gaucher 's Disease
- Myeloperoxidase deficiency (MPO) - CORRECT ANSWER - - Gaucher 's Disease
Gaucher's disease is a monocyte-macrophage disorder caused by a rare genetic defect. There is a
high incidence of this disease in Ashkenazi Jews. There are two types of the disease:
neuronopathic and nonneuronopathic, depending on symptoms. The disorder represents a
deficiency of B-glucocerebrosidase, the enzyme that normally splits glucose from its parent
,sphingolipid, glucosylceramide. As a result of this enzyme deficiency, cerebroside accumulates
in histiocytes (macrophages). Gaucher cells, typically a large cell with one to three eccentric
nuclei and a characteristically wrinkled cytoplasm, are found in the bone marrow, spleen, and
other organs of the mononuclear phagocyte system. Gaucher cells are rarely seen in the
circulating blood.
Chediak-Higashi syndrome is a congenital neutrophil abnormality. Because of an abnormal
granulation of neutrophils, it results in a qualitative neutrophil disorder of neutrophils. The
neutrophils with giant granules display impaired chemotaxis and delayed killing of ingested
bacteria.
Chronic granulomatous diseases(CGDs) are congenital neutrophil abnormalities. They are a
genetically heterogeneous group of disorders of oxidative metabolism affecting the cascade of
events required for H2O2 production by phagocytes during phagocytosis. Life-threatening
infections can result. Patients with autosomal-recessive form may have a less severe clinical
course than patients with X-linked forms of CGD
Myeloperoxidase deficiency is a congenital neutrophil abnormality. Myeloperoxidase is an iron-
containing heme protein responsible for the peroxidase activity characteristic of azurophilic
granules in neutrophils. Human neutrophils contain many granules of various sizes that are
morphologically, biochemically, and functionally distinct. The azurophilic granules normally
contain
The term TITER (as it applies to the measurement of antibodies) is best defined as:
- Concentration of antibody in the serum
- Maximum reactive dilution X 100
- Maximum reactive dilution / 100
- Reciprocal of maximum reactive dilution - CORRECT ANSWER - - Reciprocal of
maximum reactive dilution
The term TITER (as it applies to the measurement of antibodies) is best defined as reciprocal of
maximum reactive dilution of the patient's serum where the antibody is still detectable. For
example, a specimen with a last reacting tube containing a 1:100 dilution, would be said to have
a titer of 100.
Which of the following types of molecules is most likely to be antigenic/immunogenic?
- Nucleic acids
- Carbohydrates
, - Lipids
- Proteins - CORRECT ANSWER - - Proteins
Proteins are complex molecules with a high molecular weight and are more antigenic than the
other types of molecules.
Carbohydrates are the second most antigenic molecules.
Lipids are the third antigenic molecules from this list.
Nucleic acids are not generally antigenic.
A physician suspects his patient might have rheumatoid arthritis. Which of the following markers
should be ordered?
- Antimitochondrial antibodies
- Anti-IgG
- Antineutrophilic antibodies
- Antimyocardial antibodies - CORRECT ANSWER - - Anti-IgG
Rheumatoid arthritis commonly presents with an increase of IgM antibodies that are directed
toward the Fc portion of IgG. These anti-IgG antibodies are called rheumatoid factor (RF).
Patients with primary biliary cirrhosis will have an increase in antimitochondrial antibodies.
Wegener's granulomatosis presents with antineutrophilic antibodies.
Antimyocardial antibodies are important markers in patients who have rheumatic fever.
Flow cytometry is a useful tool in the study all of the following disorders, EXCEPT?
- HIV
- Leukemia
- Viral hepatitis
- Lymphoma - CORRECT ANSWER - - Viral hepatitis
Viral hepatitis is diagnosed primarily by ELISA or molecular techniques.
