What is Arneth index| Schilling index |Importance |Blood|

        

                     Arneth count &Index and Schilling index

                   What is Arneth count and index?

Table of contents

1.	Arneth count & index
2.	Schilling test
3.	Precursor cells
4.	Importance

Polymorphonuclear is a type of white blood cells. It is also called a neutrophil.

When a neutrophil is formed in the bone marrow, it has a profoundly indented nucleus-single lobed nucleus which is typically U-shaped, and it is called a Stab cell or Schaf's cell. When it is released into the circulation, its nucleus is bilobed. As the cell matures, the number of lobes of the nucleus increases from one to five or six. A very old neutrophil is known as 'Senile neutrophil.'

The development of lobes in the nucleus is very constant. Therefore, one can predict the age of a neutrophil. One can recognize young, mature, and old neutrophils.

Arneth counted 100 neutrophils and arranged the cells according to the nuclear lobes. This gives % of neutrophils. 

If we count 100 neutrophils in a blood film, the number of neutrophils according to the numbers of lobe the result is as follows:

                                                 

Stage	Percentage of Neutrophils	Number of lobes
I	5%	One lobe
II	30%	Two lobes connected by a single chromatin thread
III	45%	Three lobes connected by two chromatin threads
IV	18%	Four lobes connected by three chromatin threads
V	02%	Five or more connected by four or more chromatin threads

                    

This is known as Arneth count after Josef Arneth. According to the nucleus shape, whether round or s-shaped each class is divided into subclasses, making it twenty-five types in total.

Sometimes it was difficult to recognize the nuclear lobulation of neutrophils and differ from person to person. So Arneth count was not accepted universally.  

Cook (1914) suggests that Arneth count is valuable in diagnosing and prognosis a disease. According to Cook, chromatin filament must connect the lobes. Following Cooks criteria, When 100 neutrophils are counted, the result is as follows:

tage	Percentage of Neutrophils	Number of lobes
I	10%	One lobe
II	25%	Two lobes connected by a single chromatin thread
III	47%	Three lobes connected by two chromatin threads
IV	16%	Four lobes connected by three chromatin threads
V	02%	Five or more connected by four or more chromatin threads

 

However, due to recent advancements in the medical field, Arneth Cook count has lost its importance.

Shilling 1920 simplified the Arneth count. In the differential count of leucocytes, each type is counted separately. Each variety of neutrophilic granular cells is expressed as a percentage of the total leucocytes. (InArneth's method, it is described only as a % of the whole neutrophilic cells). Total neutrophilic granular cells 67%.
Stage           Name            Percentage of cells
     I         Myelocyte            0%
     II       Metamyelocyte      0-1%
     III      Older Metamyelocyte 3-4% Band cells
     IV      Neutrophils               64%.
The Arneth index is the sum of the cells in the first two groups.
Bushnell and  Treuholtz proposed that Arneth index =sum  of the  
group I+ group II+1/2 of group III.   
Q.How long a neutrophil lives? 

A.The average life span of neutrophils is 8 to 10 hours only.

Q. What is a left shift or regenerative shift?

 A. when neutrophils with one, two, and three-lobed nuclei are more than 80%, it is called shift left or regenerative shift.

This 'shift to the left indicates that bone marrow is hyperactive, rapidly making cells, and is seen in acute infection, especially pyogenic and bleeding. It suggests that the body can react in need and emergency appropriately.

Q. What is 'shift to the right' or degenerative shift?

A. when neutrophils with four, five, and six lobed nuclei are more than 20%, it is called 'shift to the right' or degenerative shift. This 'shift to the right indicates that bone marrow is hypoactive. It is seen in pernicious anemia, vitamin deficiency, aplasia of bone marrow. It shows that the body cannot react in need and emergency appropriately. Even in acute infections, the bone marrow will not form cells to counter the ill effect of microorganisms.

Nowadays, Arneth count or index is not commonly used.

                                            

    

                    

Stage I

                                           

      

                               

Stage 2

                                         

          

    

                              

                                         

               

                                    

                                        

       

                                    Schilling's Index 

The Schilling's hemogram after the name of Viktor Theodor Adolf

 George Schilling counts the different developmental stages of

 white blood cells in the peripheral blood.

Four stages of neutrophil are found in the peripheral blood. Their

 average percentage in adult blood are as follows,

The total neutrophil is 67% of W.B.C.    

Stage	Percentage of cells	Description of the cell
Myelocyte	0%	Large cell, spherical nucleus, and fine granules in the cytoplasm
Metamyelocyte	0-1%	Slight indentation of the nucleus.
Older Metamyelocyte	3-5%	Early nucleus lobulation starts, and the cell is known as Band cell or Staff cell.
Neutrophils	62-65%	Other stages of neutrophils.

Precursor cells are present in the peripheral blood in the rapid

 formation of white blood cells.

                                            Schilling Test

                Schilling"s test of Vitamin B12 absorption test is used to differentiate megaloblastic anemia due to intrinsic factor deficiency pernicious anemia from other causes of B12deficiency.

     Internal link: https://blog.totalphysiology.com/2021/01/white-blood-cell leucocytes.html

 External link: https://en.m.wikipedia.org>wiki