labCE

Question 1

what sero-marker is the first marker to become positive in Hepatitis B and is associated with the infective stage?

Answer 1

HBs antigen

*Hepatitis B surface antigen, or HBs, is a protein that is present on the surface of the virus. The protein will be present via laboratory testing in the blood with acute and chronic HBV infections

Question 2

the serum hemolytic complement level (CH50)

Answer 2

is a measure of total complement activity

*Total hemolytic complement, or CH50, is an assay used to evaluate the complete complement sequence. CH50 is often decreased in SLE, glomerulonephritis and other immune complex diseases. A normal CH50 level indicates that all the components, C1 through C9, are present.

Question 3

the mediator cells that bind MOST to IgE antibodies are:

Answer 3

basophils

*Allergen-specific IgE, synthesized in response to allergens, becomes fixed to receptors on cellular membranes, especially those of basophils. If these receptor-bound IgE molecules are aggregated on re-exposure to specific allergen, both mast cells and basophils produce mediators that result in the allergic response. IgE-antigen interaction at the cell surface causes degranulation of cells and release of substances including: histamine, SRS-A, platelet activator, a kallikrein, and an eosinophil chemotactic factor. Basophils are the principal cells that bind IgE antibody while their number of receptor sites is proportional to serum IgE levels. Eosinophils are drawn to the site by the basophil chemotaxis mechanism, but are not the main cell which binds the IgE antibody.

Question 4

Jane Doe is a 39-year-old female who felt tired for several months, had pain in the joints of her fingers, and recently developed a dermatitis following exposure to the sun. The following test results were obtained on a blood sample drawn during the initial evaluation:

Total Protein = 8.4 gm/dL (N = 6.0-8.0 gm/dL)
ANA >1:2560; speckled pattern
CRP = positive
C3 = 40 mg/dL (N = 80-180 mg/dL)
C4 = 5 mg/dL (N = 15-45 mg/dL)

Based on the clinical and laboratory findings, what disease should be suspected?

Answer 4

SLE

*The ANA titer is usually less than 1:160 in diseases other than SLE, so that the possibility of SLE is increased in patients with higher titers. A speckled pattern is commonly found in patients with SLE indicating binding to a variety of nonhistone, small ribonucleoprotein (RNP) particles. A high crp level indicates that inflammation is occuring, as in SLE for example, but does not indicate the location or cause of the inflammation. Decreased complement levels also are associated with autoimmune diseases. Both C3 and C4 levels are typically depressed in SLE