Leukocytosis and Leukopenia – White Blood Cell Pathology

00:02 Here, we’ll take a look at quantitative disorders.

00:04 We’ll take a look at the spectrums of quantitative WBC pathology.

00:08 Meaning to say, you could have too much or too little.

00:12 Let’s first take a look at a hierarchy of your WBCs.

00:16 Your total WBC count should be between 4,500 to 11,000.

00:22 Your segmented neutrophil should be at the highest at being approximately 56%.

00:27 Lymphocytes should come in second at 34%.

00:30 Monocytes at 4%.

00:32 Bands, let me pause here for a second.

00:35 Understand that normally speaking, you should have a little bit of primitive neutrophil in your circulation, it being bands.

00:42 This is a normal WBC count, 3%.

00:46 Eosinophils at 3%, and down in the basement, your basophils will be a measly 0.3%.

00:53 Now, what you want to keep in mind is that for any reason, if you find your WBC count to be elevated, well, what exactly is causing the WBC count to be increased? Is it due to, perhaps, infections? Maybe neutrophils are causing the increase in WBC.

01:10 Is your patient suffering from allergies? That WBC count will be increased there due to increase in eosinophils.

01:16 Please be able to properly walk through the different causes of WBC count.

01:24 Our topic will go through leukocytosis, neutrophilic leukocytosis, lymphocytosis.

01:30 Our focus mainly will be on neutrophilic leukocytosis because of the important differentials that we shall come to.

01:37 Now, remember when you say leukocytosis, you’re talking about all WBCs that are increased.

01:44 This may include neutrophilic, may include lymphocyte, eosinophils, basophils, or perhaps, monocytes.

01:53 On the other hand, meaning to say the spectrum of quantitative disorders, here, we’ll find a decrease in WBC count.

01:59 This is then referred as being leukopenia.

02:03 Now, if there is a drop in neutropenia, what may then have caused this? We’ll take a look.

02:07 Or maybe there is lymphopenia as maybe seen with HIV.

02:14 Under quantitative disorders, let’s say that there was a patient who had type 1.

02:18 HSR stands for hypersensitivity reaction, or maybe invasive helminthic infection such as ascaris lumbricoides.

02:26 Well, let’s say that the patient, in fact, had a type 1 type of allergy or anaphylactic shock in which there were isotypes switching with the IgE then landing upon a mast cell.

02:37 This mast cell is then going to release quite a bit of histamine.

02:41 In addition to that, you have involvement of eosinophils with allergies, a type 1 hypersensitivity.

02:47 Or you can have an invasive helminth in which, let’s say, that you have a patient that has developed gastroenteritis, secondary to ascaris lumbricoides.

02:56 At some point in time, you might have in helminth that then passes through your pulmonic system or respiratory system.

03:02 When this occurs, you should know as well that the granules within eosinophil, if you remember correctly, contain major basic protein.

03:10 Major basic protein is the particular “enzyme” within the granule of an eosinophil, which we’re seeing here in the picture.

03:18 Take a look at it, please.

03:19 It is rather pinkish, and this is then going to release major basic protein to combat the helminth.

03:26 If you have myeloproliferative disorders, I want you to take a look at the color here of this cell, and I’d like for you to compare the color of this cell to the one on the left.

03:35 Both of these are granulocytes.

03:38 However, totally different responsibility.

03:41 On your right, let’s say that one of your myeloproliferative disorder had the translocation of 9 and 22.

03:46 And you should know the chronic myelogenous leukemia, which is the topic we’d take up in a little bit, may result in increased number of all myeloid cells.

03:55 And we say myeloid cells, you should be referring to all cells except your lymphocytes, T-cells, B-cells, and natural killer cells.

04:04 My point is this, if you find basophilia taking place in your patient, maybe perhaps, high on your differential, it should be myeloproliferative disorder such as chronic myelogenous leukemia.

04:16 Let’s say that your patient is suffering from a viral infection, or maybe your patient has a whooping cough type of issue.

04:26 Obviously, I’m referring to pertussis.

04:28 Now, what’s interesting is the fact that viral, you should quite be familiar with, meaning to say that you have a lymphocyte, as you see here, and the lymphocyte with the nucleus being approximate in size of this rounding RBCs, well, you would bring up a lymphocyte type of reaction, lymphocytosis.

04:48 But why is the bacteria here known as bordetella pertussis? Because bordetella pertussis inhibits the entry of lymphocyte into a lymph node, therefore, you would expect to see absolute lymphocytosis.

05:01 What if you found monocytosis? Well, in this case, you’re talking about chronic inflammation.

05:06 In chronic inflammation, remember, beyond the third day, the neutrophils will undergo apoptosis, and this will then be replaced by your monocytes.

05:14 And then coming into a tissue, you would then call these macrophages.

05:18 On this spectrum or on this end of the spectrum of quantitative disorders, this is an increase and increase and increase of different types of WBCs.

05:28 Overall, giving the WBC an increased count, but then depending as to which particular WBC, either a granulocyte or agranulocyte or even a lymphocyte is then giving you a picture of leukocytosis.