Medical Specialty >> Hematology

Doctors Lounge - Hematology Answers

Back to Hematology Answers List

If you think you may have a medical emergency, call your doctor or 911 immediately. Doctors Lounge ( does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site.

DISCLAIMER: The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Please read our 'Terms and Conditions of Use' carefully before using this site.

Date of last update: 10/12/2017.

Forum Name: Hematology Topics

Question: 13yo low WBC & neutrophils, high RDW & monocytes

 MOM2PALPJL - Wed Jul 14, 2010 8:48 am

My 13yo son had labs on 5/20 w/ RDW 15.6, Monocytes 11%. At this time WBC was 4.7 & Neutrophils 51%. Dr suggested iron & b-12 supplements & repeat labs. Bought b-12 sublingual methylcobalimin 1000mcg's & chewable vit w/iron & w/in 10 days my child looked better than he had in years. He had been very tired, run down, always w/ dark circles, could be very irritable but also 13... also underweight, 62" & 84lbs. He has always been skinny though. Anyway, we were going to repeat labs in 3 mo. We were back at dr's for my daughters annual visit, and she also was amazed at the remarkable improvement in his appearance, ordered more labs, this time to r/o celiacs and check for specific levels of iron & b-12. He has also had stomach pains, leg & joint pains, just very tired. This all improved too & his weight was also up to 89. Labs done on 6/30 all negative for anything celiacs related, RDW still 15.6, Monocytes still 11%, but WBC now 4.0 and Neutrophils 41% w/ absolute neutrophils at 1640. Vitamin b-12 847, Folate serum 16.5 & Ferritin 19. Dr also suggested crohn's as possibility. Seems like he was not absorbing nutrients but unsure - just looking for understanding as to what our next step should be. Thanks so much in advance.
 Dr.M.Aroon kamath - Mon Aug 09, 2010 3:16 am

User avatar Hi,
The high RDW helps in determining if there is only a B12 and/or folic acid deficiency (with normal RDW showing the red cells are mostly the same size) or with concomitant iron deficiency (a high RDW due to small and large red blood cells).

The normal reference range for an absolute monocyte count is
40 - 950/µL. A value >950/µL is called as Monocytosis.

Monocytosis is seen in some of the following disorders,
- recovery phase of many acute infections,
- chronic infectious disorders (tuberculosis),
- chronic inflammatory bowel disease,
- rheumatic diseases (lupus, rheumatoid arthritis),
- malignant processes (Hodgkin's and non-Hodgkin's lymphoma),
- granulomatous diseases: sarcoidosis, histiocytosis X,syphilis, brucellosis, Crohn's disease etc)
- storage diseases (Niemann–Pick disease,Gaucher's disease),
- Parasites (malaria),&
- drugs (methsuximide, griseofulvin, and haloperidol).

The slightly increased monocyes in a differential count in the case of your son, indicate need for an absolute monocyte count. As your doctor suspects, Crohn's disease can be one of the possibilities.

Many children with myelodysplasia syndrome(MDS), may exhibit monocytosis. Most of these cases will also have blasts(>5%), without an excess of blasts in the bone marrow.The presence of blasts in the blood may lead to this condition being labeled as juvenile myelomonocytic leukemia(JMML).

Your son has indeed responded to vitamin B12 and folic acid. However, other tests to assess the iron status such as transferrin saturation may be needed as the ferritin value, although seemingly within range(closer to the lower limit of normal), may still be associated with depleted iron stores.

You next step, at least as far as this forum is concerned, should be to provide us all the test results of your son (the complete blood count, reticulocyte count, absolute monocye count, ESR, peripheral smear examination etc), so that it may be possible to narrow down the differential diagnoses.
Best wishes!

| Check a doctor's response to similar questions

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us