Semi-solid phase assay for the alternative complement pathway activity assessment (AP₁₀₀)

Since the introduction of the most expensive drug in the world (Eculizumab) in the therapeutic arsenal of many diseases involving the alternative complement pathway (ACP) in their pathophysiology, the unmet need to perform simple ACP assays affordable for all countries has become one of the major challenges of the contemporary medicine. The assay currently used is AH₅₀, despite it still challenging for several laboratories. This educational chapter consists of a detail protocol of standardized hemolytic assay AP₁₀₀ and aims to help clinical laboratories over the world and especially those of the developing and low income countries to perform it. The procedure is essentially the same as for the timed lysis assay and dilution methods (AP₅₀) except the concentration of ACP buffer and the chicken erythrocyte density used to make the gels. In clinical field, AP₁₀₀ has at least nine applications in disease diagnosis and follow-up. AP₁₀₀ has many advantages over the AH₅₀ as it is more reliable for the Eculizumab monitoring and more practical with a purpose to be stored and transported for several weeks. AP₁₀₀ is a portable and easy to use device both at the bedside and in the companion medical care.