Quantcast Factors Affecting the First Stage (Sensitization) - Immunohematology and Blood Banking II

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
b. Factors Affecting the First Stage (Sensitization). Red blood cell
sensitization with antibody obeys the law of mass action. Thus, the reaction between
antigen on the RBC surface and antibody is reversible and the quantity of
cell-bound antibody at equilibrium will vary depending on the reaction conditions and the
equilibrium constant of the antibody. The reaction conditions should be designed to
maximize the quantity of cell-bound antibody at equilibrium in order to facilitate
detection of either blood group antigen or antibody. Some of these reaction conditions
are described below:
(1)  Temperature. Most blood group antibodies show their greatest reactivity
over a restricted temperature range, some reacting optimally at 4C, others at 37C.
Antibodies reacting optimally at 37C have been described as "warm" antibodies, and
those reacting optimally at lower temperatures as "cold" antibodies. Agglutinins
(antibodies) having maximum reactivity at one temperature may have sufficient thermal
amplitude to be active at others. Antibody activity is usually tested at room temperature
and at 37C. Antibodies active at 37C are the most clinically significant, although "cold"
antibodies cannot be ignored if they have a wide thermal amplitude (for example, above
30C). Antibodies only reacting at lower temperatures may be of importance in patients
subjected to hypothermia.
(2)  pH. The pH optima for antibody reactivity in most blood-group systems
have not been investigated. For anti-RhO(D), the optimum pH lies between 6.5 and 7.
Antibodies of other blood-group specificities may have different pH optima (for example,
some examples of anti-M react best at pH 5.5).
(3)  Incubation time. Time is required for the antibody RBC reaction to reach
equilibrium. The amount of time required to reach this state will depend upon other
variables. The rate of antibody binding is greatest initially, so incubation times for
routine laboratory procedures may be relatively short (for example, 15 to 30 minutes).
Ionic strength.
(4)
(a) The ionic strength of the reaction medium is one of the
physiochemical conditions that play an important role in the binding of antibody to RBC
antigens. Ionic strength is a measure of intensity of the electrical field resulting from
ions in solution. Electro-static forces (interaction of positive and negative charges) play
an important role in antibody reaction involving RBCs. Red blood cells carry a large
electronegative charge, which serves to keep them from spontaneously aggregating.
This enables them to function efficiently in oxygen transport by maintaining a maximum
surface area available for gas diffusion. When RBCs are suspended in an electrolyte
solution (0.85 percent NaCl), the cations (positive) are attracted to the negatively
charged RBCs, and the RBC becomes surrounded by a diffuse double layer ("ionic
cloud"), that travels with the RBC as if it were part of it. The outer edge of this layer is
called the surface of shear or the
MD0846
1-13



Medical News
West Africa seals off Ebola outbreak epicentre
West Africa's Ebola-hit nations announced a cross-border isolation zone on...
medicalxpress.com
New research characterizes in-flight pediatric deaths
In a first-of-its-kind study, researchers at University Hospitals Rainbow Babies...
medicalxpress.com
Medicine X symposium focuses on how patients, providers and entrepreneurs can ignite innovation
A special Medicine X event on Sept. 4 will explore...
scopeblog.stanford.edu
Pepper and halt: Spicy chemical may inhibit gut tumors
Researchers at the University of California, San Diego School of...
medicalxpress.com
Study reveals one reason brain tumors are more common in men
New research at Washington University School of Medicine in St....
medicalxpress.com
Clues to curbing obesity found in neuronal 'sweet spot'
Preventing weight gain, obesity, and ultimately diabetes could be as...
medicalxpress.com
This Week: Lifestyle Medicine, More Ebola Troops
(MedPage Today) -- Another popular guest post on healthy hearts,...
medpagetoday.com
FDA Approves Long-Acting COPD Inhaler
(MedPage Today) -- The FDA approved another once-daily bronchodilator, olodaterol...
medpagetoday.com
Why isn't there a treatment or vaccine for Ebola?
In the four decades since the Ebola virus was first...
medicalxpress.com
Ebola-hit African states seal off outbreak epicentre
Guinea, Liberia and Sierra Leone announced Friday an isolation zone...
medicalxpress.com
Expressive writing may help breast cancer survivors
Writing down fears, emotions and the benefits of a cancer...
medicalxpress.com
Friday Feedback: GME Beyond Repair?
(MedPage Today) -- Do you think medical residents today are...
medpagetoday.com
PodMed: A Medical News Roundup From Johns Hopkins (with audio)
(MedPage Today) -- This week's topics include the benefits of...
medpagetoday.com
Can’t remember being a baby? Rapid growth of new neurons in young brains may explain why
A close friend once told me that one of her...
scopeblog.stanford.edu
Obesity in Women Linked With Early RA
(MedPage Today) -- Women who are overweight or obese, particularly...
medpagetoday.com
Ebola outbreak speeds up efforts to find a vaccine
There is no vaccine on the world market to protect...
medicalxpress.com
STDs on the rise in Miami area
Rates of both chlamydia and syphilis in Miami-Dade have nearly...
medicalxpress.com
Florida officials issue warning on Vibrio bacteria
(HealthDay)—Florida health officials are cautioning visitors to the state's beaches...
medicalxpress.com
Dementia Tied to More ICD Placements
(MedPage Today) -- Dementia patients get more implantable cardioverter-defibrillators than...
medpagetoday.com
More than half of general surgery residents want to quit
(HealthDay)—A majority of categorical general surgery residents seriously consider leaving...
medicalxpress.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +