Diagnostic Pitfalls during Therapy for Extreme Hypertriglyceridaemia

We report the case of a 34-year-old man with extreme hypertriglyceridaemia (276.6 mmol/l) that was corrected by diet and triple-drug therapy. No primary defect could be found despite an intensive biochemical and genetic evaluation. Early in the time course of triglyceride-lowering therapy, the composition and concentration of different lipoprotein species changed markedly. His lipoprotein profile mimicked type III hyperlipidaemia, then familial hypercholesterolaemia, and finally hyperalphalipoproteinaemia. The increase in LDL cholesterol and apolipoprotein B was paralleled by a sixfold increase in lipoprotein(a). We conclude that these different forms of hypercholesterolaemia disappear solely with a continuation of the triglyceride-lowering therapy.