Haptoglobin vs. Free Hemoglobin to Measure Intravascular Hemolysis

This is the question:

When testing if a type II hypersensitivity reaction occurred we learned you can use free plasma hemoglobin levels. Wouldn't haptoglobin levels be a better estimation if what we are testing is intravascular hemolysis?

Haptoglobin is produced in the liver.  It binds free hemoglobin in serum and it is an acute phase reactant.  Its primary function appears to be the irreversible binding of free oxy-hemoglobin in plasma.  Haptoglobin prevents the loss of hemoglobin to urine and conserves iron.  The total circulating haptoglobin is capable of binding about 3 g of hemoglobin and it may be completely depleted by a single severe episode of hemolysis.  If the RBC destruction is occurring in the liver or spleen, the haptoglobin level will be normal because the free hemoglobin is not being released into the bloodstream. 

The haptoglobin test is used primarily to help detect and evaluate hemolytic anemia and to distinguish it from anemia due to other causes.  However, it cannot help determine the cause of the hemolysis.  Serial determinations are used to detect and monitor acute phase reactions and hemolytic states.  If the haptoglobin level, RBC count, hemoglobin, and hematocrit levels are decreased and the reticulocyte count is increased it is likely that you have some degree of hemolytic anemia.  If the haptoglobin level is decreased and there is no sign of hemolytic anemia, then it is possible that the liver is not producing haptoglobin.  Liver disease may also decrease the haptoglobin levels, because of decreased production.  Plasma haptoglobin is increased in acute phase reactions and in burns and nephritic syndrome.  Low haptoglobin levels occur in increased intravascular hemolysis or hemoglobin turnover, which is seen in hemolytic anemias, transfusion reactions, and malaria.  Chronic intravascular hemolysis causes a small but continuing drop in haptoglobin levels.  Haptoglobin levels will return to normal within 2-3 days unless the hemolysis persists. 

Plasma free hemoglobin binds to haptoglobin and this complex is rapidly removed by the parenchymal cells of the liver.  The free hemoglobin, in excess of the binding capacity of haptoglobin, is excreted in the urine.  The urine will be chocolate brown colored.

I have not found information supporting one test over the other.  I think that haptoglobin is probably the more commonly ordered of the two tests.  The haptoglobin test might be better since the free hemoglobin is excreted in the urine.  I do know that serial determinations are better than a single measurement to monitor the level of hemolysis.           

Lab Etiquette, Dress Codes, and Safety

Lab Etiquette

The lab techs that are teaching in the clinical lab will often have patient work to complete while they are teaching.  Therefore, they need your attention in order to effectively teach you and complete their work.  When I talk about lab etiquette, I am mainly talking about cell phone use.  Med. Tech. students should not be using their cell phones in the lab.  First, it is impolite to text while someone is teaching you and you cannot concentrate on two things at once.  While you are working on instruments your full attention is needed and you cannot be distracted by a cell phone.  Even if you are not working on an instrument, you still need your full attention on your training.  This year is the hardest and most intense year of your education and it is the most comprehensive preparation for the registry.  Once you start working, you will not use your theory nearly as much as you do during your clinical rotation.  The lab techs will take into consideration the fact that you might be waiting to hear for a job offer.  You just need to mention it to them and they won’t mind if you take a call.  This should be a rare occurrence, though.

Dress Codes

There is a dress code in the laboratory.  The female employees are required to wear scrubs and the male employees wear dress pants, a dress shirt, and a tie.  The students are required to wear dress pants and the Med. Tech. student polo shirts.  Your shoes should impervious to fluids and have a back on them.  Cloth shoes should not be worn because of the chance of spilling blood or body fluids on them.  You would not want to get blood or body fluids on your feet.  This is the dress code for our laboratory; it may be different at other laboratories.  If you find a different dress code please share it with us in the comment section.   

    

Lab Safety

In the laboratory we work with a lot of potentially infectious samples and all samples are treated as such.  All lab techs are required to wear disposable lab coats.  Technologists are also required to wear gloves when handling potentially infectious specimens.  When you are wearing your gloves you should not be touching your face, your hair, or your cell phone, because once you have touched specimens you do not know what is on your gloves.  I would consider most every surface in a laboratory to be dirty.  Think of it this way; would you want to set your lunch box on a counter in the laboratory and then set it on your kitchen table where you eat?  I sometimes see students chewing on a pen.  That is definitely something that you should avoid.  Also, food and drink are prohibited in the laboratory work areas.  You are only allowed to have food and drink in designated areas, such as the staff lounge.       

Years ago, before there was information available about the hazards of handling specimens, the practices were very different.  Techs did not wear gloves and mouth pipetting was a common practice.  Then with the discovery of the transmission mode of AIDS and HIV and other infectious diseases, a lot of the regulations changed.  Techs were then required to wear gloves and other personal protective equipment.  This was hard for some of the older techs and I still occasionally see a few handling specimens without gloves on.  The laboratory is a safe place to work as long as you wear your personal protective equipment and take the proper precautions.   

Welcome to the Med Tech Student Blog

I am writing this blog to help inform Medical Technology or Clinical Laboratory Science students about what to expect during their year of clinical training. I want to start the blog with a question and answer format and then expand to other topics as the blog evolves. I plan on posting once a week and I will take my topics from the questions that have been presented.


About the Author



Chemistry Analyzer

My name is Julie and I am a Medical Technologist at a mid-sized hospital in Pennsylvania that currently has a school of Medical Technology. I have a Bachelor’s Degree in Medical Technology, a Master’s Degree in Business Administration, and a Master’s in Education in Business/Workforce Development. I have been a Medical Technologist for 22 years. I perform phlebotomy on patients of all ages and I perform chemistry and urinalysis testing. I also teach the Medical Technology students in the clinical laboratory.
 

Venipuncture

 



Calcium Oxalate Crystals in Urine
(Square crystals with an X in the middle)



Educational Requirements for the School of Medical Technology

To attend a school of Medical Technology, students must have a bachelor’s degree with the chemistry, biology, and math requirements or be enrolled in a 3 plus 1 program with an affiliated college. In the 3 plus 1 program you attend a college for three years and your final year is at the school of Medical Technology. When you are finished you will have a bachelor’s degree and a degree from the school of Medical Technology.

Clinical Training

The clinical training will be one of the most challenging years of your education. In some schools the students spend the first 6 months in the classroom learning theory and then they spend the next 6 months in the clinical laboratory for hands on training. Other schools have a student laboratory, where students learn about the tests before they enter the laboratory. The students will also learn to perform phlebotomy procedures on patients.  Other schools may vary in structure and I am not sure if all schools teach phlebotomy.  If you find anything different please post in the comment section.      

ASCP Certification

In Pennsylvania you are required to be certified by ASCP or the American Society of Clinical Pathology. If you are certified after January 1, 2004, then you are required to participate in the International Certification Maintenance Program every three years in order to retain your certification. This is a continuing education program that will help you to excel in your career. Take a look at this link for more detailed information.  http://www.ascp.org/

Comment Policy

I encourage you to leave comments. I will review all comments before they are posted. I'll reply to all questions within a week, and errors in the posts will be acknowledged in the comment area. Feel free to disagree with my points if there is need for disagreement, but keep in mind that all off-topic comments, disparaging comments, comments with more than one link, and comments that include profanity will be deleted.