Features
The Urit BH7000 detects 35 parameters, including the six leukocyte populations (LYM, MON, NEU, EOS, BASO, and IMG or immature granulocytes) and reticulocytes.
Reticulocytes are automatically determined during general analysis if selected.
It uses only 28 µL of sample and has a speed of up to 60 samples/hour when working without reticulocytes and 40 samples/hour when working with reticulocytes.
Reagents
The system uses six different reagents:
LD Lyse
DF Dye
DR Diluent
FR Dye
DS Diluent
LH Lyse
Technology
The Urit BH7000 uses flow cytometry + laser + fluorescence technology.
What's new compared to traditional analyzers like the Smart V5 is the use of fluorescence for optical cell detection.
The larger the nucleus, the more DNA there is, and therefore, the more cells are stained and emit more fluorescence.
When the analysis is complete, the analyzer will display 5 scattergrams on the screen:
Optical Platelets
One of the advantages of this analyzer is the ability to detect platelets optically rather than by impedance. This avoids interference and erroneous results. Furthermore, the reagents "break up" the aggregates, allowing for a more accurate count. This is especially important in cat samples.
IMG – Immature Granulocytes
The immune system comprises three types of granulocyte cells: eosinophils, basophils, and neutrophils. These cells are the result of a six-stage differentiation process in the bone marrow called granulopoiesis. The first recognizable cell in this differentiation process is the myeloblast. The other stages in the order of differentiation are promyelocytes, myelocytes, metamyelocytes, and band cells, respectively.
Immature granulocytes represent three cell populations: promyelocytes, myelocytes, and metamyelocytes.
What is their clinical significance?
Under normal conditions, these populations are absent from peripheral blood, except in newborns, and a significant number should prompt further investigation. In fact, in some cases, a high population of immature granulocytes, also called "left shift," can be observed in peripheral blood. It typically reflects increased myeloid cell production in pathological conditions that could include inflammatory infection, severe hematologic disease, cancer, tissue necrosis, acute transplant rejection, surgical or orthopedic trauma, myeloproliferative diseases, steroid use, and also pregnancy.
Reticulocytes
In addition to the five leukocyte populations, the main characteristic of Urit is its ability to determine reticulocytes.
Reticulocytes are immature RBCs. Slightly larger than RBCs, they mature in the bone marrow and circulate for a few days in the blood before fully developing into RBCs. Like RBCs, mammalian reticulocytes do not have a nucleus.
They are called reticulocytes because, once stained, the rRNA (ribosomal RNA, the precursor of DNA) network can be observed under a microscope.
The analyzer gives us values in total number (RET#) and percentage (RET%), and also indicates the ratio of immature reticulocytes to the total (IRF).
Reticulocytes take about 7 days to convert into red blood cells.
There are two types of reticulocytes: punctate and aggregate.
Punctate does not indicate regeneration, aggregate does.
Punctata stain with low fluorescence (HFR), a stronger color, and are very close to the red blood cells. They are not significant because they are also preserved from past regenerative anemias.
On the other hand, aggregata stain with medium or high fluorescence (LFR/MFR) and are further away from the red blood cells. Many analyzers do not allow them to be differentiated, but they can be distinguished on the Urit reticulocyte graph.
What is their clinical significance?
The RET count in healthy patients is low, but some conditions or diseases cause an increase in RET counts.
In cases of anemia, the body increases RBC production and releases them into the blood earlier, causing the RET count to increase.
Hemolysis can cause anemia and can be caused by inadequate transfusion or immune-mediated diseases. Anemia can occur in puppies due to the presence of fleas.
Some medications can also cause an increase in RET counts without anemia.
The main reason for a low RET value is non-regenerative anemia, which occurs in patients with tumors, chronic inflammation, feline leukemia, viral infections, medical treatments, etc.