**4. Discussion**

Since Thomas A. E. Platts-Mills and Kimishige Ishizaka have discovered that fresh normal human serum in EGTA buffer was found to cause >90% hemolysis of unsensitized rabbit red blood cells (RaRBC) [11], simple timed lysis assay and dilution methods called AP50 (Alternative Pathway 50) was performed to quantify hemolytic complement activity in human serum [13–15]. This reaction requires C3, factors B and D, and Mg++ ions to form the C3 convertase (C3bBb) [14, 15]. In AP50, ACP is activated and measured by virtue of RaRBC decreased sialic acid content in addition to the blockade of the classical pathway activation by chelation of calcium by EGTA [16]. Nonetheless, AH50 requires a lot of material like spectrophotometer and consumable test tubes and highly skillful personal. To adapt this assay to simple labs, a semi-solid phase assay was proposed to measure ACP activity by using chicken erythrocytes incorporated in agarose gel called AP100. Cell membranes of chicken erythrocytes have the same properties as those of the


**109**

*Semi-Solid Phase Assay for the Alternative Complement Pathway Activity Assessment (AP100)*

rabbit in terms of cell surface charge density of sialic acid whereas they are more robust than rabbit because they have nuclei. AP100 assay has many advantages over the AH50 one (**Table 2**). For example, AP100 is more reliable for the eculizumab monitoring as shown in the article we have recently reviewed [17]. Moreover, AH50 still challenging in low incomes country laboratories that cannot equip their hospital and research laboratories to perform this assay. To overcome this roadblock, it was proceeded to render this method more practical to each laboratory with a purpose to be stored and transported for several weeks. This includes a hemolytic agarose dishes/plates; a special adaptation to prevent complement activation via the classical pathway and facilitate complement activation via the alternative one

To the best of our knowledge there were no laboratory performing that assays in developing countries especially in Africa and no educational chapter is available to explain it. Once its optimization in each of these countries laboratories was performed, thanks to ACP dishes/plates, we are expecting to empower doctors' decision making process and improve quality of patients' management and therapy follow-up. Therefore this portable and easy to use device even at the bedside of the patient and in the companion do not necessitate any equipped laboratory and may facilitate prospective analysis and disease screening in large populations. With enlargement of the ACP disease spectrum necessitated complement blockade, AP100 should be considered by clinical laboratory scientist especially to analyze sets of samples at once.

I am very thankful to my all students; Ahlem Lamnai, Souad M'hamedi, Saadia

*DOI: http://dx.doi.org/10.5772/intechopen.81743*

in agarose gels.

**Acknowledgements**

Benmadi, Wasila Aeid.

The author has nothing to disclose.

**Disclosures**

**A.Appendix**

#### **Table 2.**

*Hemolytic agarose assay features in comparison to tube hemolytic assay.*

*Semi-Solid Phase Assay for the Alternative Complement Pathway Activity Assessment (AP100) DOI: http://dx.doi.org/10.5772/intechopen.81743*

rabbit in terms of cell surface charge density of sialic acid whereas they are more robust than rabbit because they have nuclei. AP100 assay has many advantages over the AH50 one (**Table 2**). For example, AP100 is more reliable for the eculizumab monitoring as shown in the article we have recently reviewed [17]. Moreover, AH50 still challenging in low incomes country laboratories that cannot equip their hospital and research laboratories to perform this assay. To overcome this roadblock, it was proceeded to render this method more practical to each laboratory with a purpose to be stored and transported for several weeks. This includes a hemolytic agarose dishes/plates; a special adaptation to prevent complement activation via the classical pathway and facilitate complement activation via the alternative one in agarose gels.

To the best of our knowledge there were no laboratory performing that assays in developing countries especially in Africa and no educational chapter is available to explain it. Once its optimization in each of these countries laboratories was performed, thanks to ACP dishes/plates, we are expecting to empower doctors' decision making process and improve quality of patients' management and therapy follow-up. Therefore this portable and easy to use device even at the bedside of the patient and in the companion do not necessitate any equipped laboratory and may facilitate prospective analysis and disease screening in large populations. With enlargement of the ACP disease spectrum necessitated complement blockade, AP100 should be considered by clinical laboratory scientist especially to analyze sets of samples at once.
