Red blood cell dynamics for gastrointestinal evaluation
Methods for identifying patients with anemia, distinguishing thalassemia-trait anemia from iron-deficiency anemia, and identifying pre-anemic patients several weeks before anemia becomes clinically detectable. Also, methods for detecting blood doping in athletes and for optimizing therapy with erythropoiesis stimulating agents or iron supplementation. Computer-readable storage devices and systems, e.g., for use in the described methods.
1. A method of screening or selecting a subject for screening for a gastrointestinal (GI) disorder, the method comprising:
in a sample comprising red blood cells from the subject who does not have iron deficiency anemia (IDA) based on a complete blood count (CBC) of the sample, determining a population mean corpuscular hemoglobin concentration (MCHC);
transforming a volume and a hemoglobin content of each of the red blood cells into an index by projecting the volume and the hemoglobin content of each of the red blood cells onto an MCHC line defined by the MCHC;
determining a sample percentage corresponding to a portion of the red blood cells in the sample in which the index of each red blood cell of the portion of the red blood cells falls below a threshold percentage of a mean projection location on the MCHC line;
comparing the sample percentage to a reference percentage; and
selecting the subject who does not have IDA for GI evaluation or further screening if the sample percentage is below the reference percentage.
2. The method of claim 1 , wherein the threshold percentage is between about 70% and about 95% of a population mean projection on the MCHC line.
3. The method of claim 1 , wherein the reference percentage is between about 10% and about 15%.
4. The method of claim 1 , wherein the sample comprises whole blood from the subject.
5. The method of claim 1 , wherein the MCHC line represents a least-squares linear fit of coordinates of volume and hemoglobin content of the red blood cells in the sample.
6. The method of claim 1 , wherein projecting the volume and the hemoglobin content of each red blood cell onto the MCHC line comprises performing a projection operation defined by
u
=
v
·
cos
θ
-
h
·
sin
θ
θ
=
-
tan
-
1
(
h
_
v
_
)
for each red blood cell, wherein v is a mean cell volume, h is a mean cell hemoglobin content, v is a volume of a red blood cell, his a hemoglobin content of the red blood cell, and u is an index of a projection of the red blood cell onto the MCHC line.
7. The method of claim 1 , wherein the GI disorder is colorectal cancer, diverticulitis, ischemic bowel, gastric cancer, gastritis, esophagitis, GI polyps, inflammatory bowel disease, or Celiac disease.
8. The method of claim 1 , wherein the GI evaluation or further screening corresponds to a GI evaluation using a colonoscopy.
9. The method of claim 1 , wherein transforming the volume and the hemoglobin content of each of the red blood cells into the index comprises:
transforming, based on a model representing a deterministic component and a random component of volume and hemoglobin content dynamics of the red blood cells, the volume and the hemoglobin content of each of the red blood cells into the index.
10. The method of claim 9 , wherein the model is based on one or more of:
(i) a magnitude of variation in a rate of hemoglobin content reduction;
(ii) a magnitude of variation in a rate of red blood cell volume reduction;
(iii) a normalized critical volume or clearance threshold;
(iv) an average rate of slow-phase volume and hemoglobin content reduction;
(v) an average rate of fast-phase volume reduction; or
(vi) an average rate of fast-phase hemoglobin content reduction.
11. The method of claim 10 , wherein the model is based on each of:
(i) a magnitude of variation in a rate of hemoglobin content reduction;
(ii) a magnitude of variation in a rate of red blood cell volume reduction;
(iii) a normalized critical volume or clearance threshold;
(iv) an average rate of slow-phase volume and hemoglobin content reduction;
(v) an average rate of fast-phase volume reduction; or
(vi) an average rate of fast-phase hemoglobin content reduction.
12. A system comprising:
a computing device comprising:
a memory for storing instructions, and
a detection module comprising one or more processors or processing devices capable of executing the stored instructions to perform operations, the operations comprising:
in a sample comprising red blood cells from a subject for screening for a gastrointestinal (GI) disorder who does not have iron deficiency anemia (IDA) based on a complete blood count (CBC) of the sample, determining a population mean corpuscular hemoglobin concentration (MCHC);
transforming a volume and a hemoglobin content of each of the red blood cells into an index by projecting the volume and hemoglobin content of each of the red blood cells onto an MCHC line defined by the MCHC;
determining a sample percentage corresponding to a portion of the red blood cells in the sample in which the index of each red blood cell of the portion of the red blood cells falls below a threshold percentage of a mean projection location on the MCHC line;
comparing the sample percentage to a reference percentage; and
selecting the subject who does not have IDA for GI evaluation or further screening if the sample percentage is below the reference percentage.
13. The system of claim 12 , wherein the threshold percentage is between about 70% and 95% of a population mean projection on the MCHC line.
14. The system of claim 12 , wherein the reference percentage is between about 10% and about 15%.
15. The system of claim 12 , wherein the sample comprises whole blood from the subject.
16. The system of claim 12 , wherein the MCHC line represents a least-squares linear fit of coordinates of volume and hemoglobin content of the red blood cells in the sample.
17. A non-transitory computer readable storage device configured to store computer readable instructions, which when executed by one or more processors cause operations, the operations comprising:
in a sample comprising red blood cells from a subject for screening for a gastrointestinal (GI) disorder who does not have iron deficiency anemia (IDA), determining a population mean corpuscular hemoglobin concentration (MCHC);
transforming a volume and a hemoglobin content of each of the red blood cells into an index by projecting the volume and hemoglobin content of each of the red blood cells onto an MCHC line defined by the MCHC;
determining a sample percentage corresponding to a portion of the red blood cells in the sample in which the index of each red blood cell of the portion of the red blood cells falls below a threshold percentage of a mean projection location on the MCHC line;
comparing the sample percentage to a reference percentage; and
selecting the subject who does not have IDA for GI evaluation or further screening if the sample percentage is below the reference percentage.
18. The non-transitory computer readable storage device of claim 17 , wherein the reference percentage is between about 10% and about 15%.
19. The non-transitory computer readable storage device of claim 17 , wherein the sample comprises whole blood from the subject.
20. The non-transitory computer readable storage device of claim 17 , the MCHC line represents a least-squares linear fit of coordinates of volume and hemoglobin content of the red blood cells in the sample.