MLT 181 Unit 3 Study Guide

In febrile agglutinin tests for rickettsial infection, Proteus OX19 detects the presence of antibodies for:

Rocky Mt. spotted fever

A patient presents with a painless genital ulcer. The patient is diagnosed as having syphilis. In what stage of syphilis is the patient?

Primary

The 1st line of defense against bacteria that the immune system uses is:

Skin & mucosal barriers

The febrile agglutinin (immunologic test) for typhoid fever is:

Widal test

The cold agglutination reaction is usually positive in which of the following conditions:

Primary atypical pneumonia

A false-negative cold agglutinin test may result if:

The specimen is refrigerated prior to serum separation

Toxoplasmosis is a serious health threat to:

AIDS patients

Cold agglutinins generally have the following antibody specificity:

Anti-I

At which stage of syphilis is the RPR the most sensitive?

Secondary

The name given to the test using febrile agglutination antigen for typhus fever is:

a. Weil Felix test

The preferred streptococcal antibodies tested after streptococcal pyoderma is

Anti-DNase B

In the test for syphilis, the RPR detects:

Reagin

Toxoplasmosis _______ is a infection:

Parasitic

Lab results on a patient indicated a positive RPR and a negative FTA. The patient had no obvious sore, rash, or other symptoms. What is the most likely cause of these results?

Another disease, such as mono

The RPR and VDRL are similar in which of the following ways?

Flocculation reactions

The order of testing for most diseases like syphilis, etc is:

1st sensitive, 2nd specific

Which of the following is a cause of a laboratory-induced false-negative in the screening tests for

syphilis?

Excess serum

Streptococcus pyogenes belongs to which Lancefield Group?

Group A

Patient serum is mixed with sheep RBCs that have been sensitized with Treponema pallidum antigens as well as with unsensitized RBCs in a separate well. Agglutination was observed in the well with sensitized red blood cells and not in the well with unsensitized red blood cells. What is the interpretation of these results?

positive for anti-Treponema pallidum antibodies

Bacteria can evade the immune system by avoiding antibodies through genetic mutation which alters the antigens.

TRUE

An RPR test done on a 19-year-old woman as part of a prenatal workup was negative, but exhibited a rough appearance. What should the technologist do next?

Make serial dilutions and do a titer.

The antigen used in the FTA-ABS test is:

The Nichol’s strain

Diagnosis of strep infections involving acute pharyngitis/tonsillitis are usually done by:

B and C

. Diagnosis of the sequelae to Strep infections is usually done by:

Serology tests

Which of the following is a confirmatory test for syphilis?

FTA-ABS

Bacteria responsible for gastric and duodenal ulcers is:

Helicobacter pylori

An ASO test was performed, but the result was negative. The patient had shown earlier clinical signs of a streptococcal pyodermic skin infection. What should be done next?

Anti-Dnase B testing

A new technologist is busy one night and has to perform an RPR on a serum sample. He does not calibrate the needle delivering the antigen and the needle is delivering a larger volume of antigen than it is supposed to. What kind of error can this cause on the test result?

Laboratory-induced false-negative due to postzone

The amount of antigen, rotator speed, & patient's serum volume used in the RPR test:

1/60 ml, 100 rpms, 0.05 ml

Which of the following is a cause of a biological false-positive in the screening assays for syphilis?

Autoimmune disease

Which best describes the antibody known as reagin?

It is tested for using charcoal and cardiolipin

A 32-year-old heterosexual male presents to the physician with a 3-day history of multiple skin lesions located on his body and his mucous membranes. He hasn’t felt well and has a low-grade fever. The patient cuts down trees in Massachusetts for a living. He is single, has had multiple sex partners, and does not use condoms. Here are the results of his laboratory tests: rapid plasma regain-reactive 1:128; Treponema pallidum-particle agglutination assay-reactive, Borrelia burdorferi IgM= <1:8; Rickettsia rickettsii IgM< 1:8. This patient has:

Syphilis

A patient has a reactive RPR at a titer of 1:128 and a reactive TP-PA. What does this indicate for the patient?

true-positive diagnosis of syphilis

What type of test is preferred for testing for H. pylori antibodies?

ELISA

.The reason that the test method in Question 35 is preferred is because it is more cost effective even though it is not very sensitive or specific.

TRUE

One symptom of rheumatic fever is:

heart inflammation

One symptom of glomerulonephritis is:

kidney failure

In the Widal test, the patient antibodies react with antigens that are present on:

Salmonella

A. pregnant woman is tested for Rh (D) blood type and her red blood cells agglutinate with anti-D. Her Rh type is:

Rh pos

A patient has the following ABO typing results:

Anti-A Anti-B Anti-A,B

4+ O 4+

A

The following are blood typing reactions for a patient:

Patient cells with

Anti-A Anti-B Anti-A,B Anti-D

4+ 4+ 4+ O

AB neg

A patient whose red blood cells are agglutinated by anti-B typing sera and not by anti-A is type:

B

In rheumatic fever, damage to the heart appears to result from:

antigenic similarity of myocardial tissue and group A streptococci

Which increase in antibody titer

from 1: 64 to 1:128

If cells from an individual are not agglutinated by serum from anyone else, this represents which Landsteiner’s blood type?

Type O

What is the 1st line of defense that the immune system uses to fight bacteria?

Skin and mucosal barriers