Sickle cell solubility test: evaluation of an in-house method

This study aims to assess the performance of an in-house sickle cell solubility test (SCT) and compare it against data published on other in-house and commercial methods. Also assessed are the effects of possible interference due to haemoglobin (Hb) level, Hb F and Hb S levels, as well as lipaemia, icterus and haemolysis index. A total of 1030 patient samples were tested by the SCT and subsequently confirmed by high-performance liquid chromatography (HPLC). Seventy-five (7.3%) samples revealed a positive SCT whereas 955 (92.7%) were negative. The sensitivity and specificity of the method was 100% and it was shown to detect low levels of Hb S (12.1%). These data show that the authors' in-house SCT method has an excellent performance against other documented methods (including some commercial kits), which is probably explained by its robustness against low levels of Hb S and interfering substances such as lipaemia. The authors believe this shows that in-house tests are able to produce highly reliable results comparable to, if not better than, certain commercially available CE-marked kits.