The invention concerns compositions and methods for assay or detection of apolipoprotein-B48 in samples. In particular, it concerns a method for differential measurement of apolipoprotein-B48 (“Apo-B48”) and apolipoprotein-B100 (“Apo-B100”) in biological samples. The invention also concerns synthetic products of Apo-B100, the corresponding antibodies, kits containing same, and their uses for detecting, differentially quantifying and/or recording an amount of Apo-B48 and/or Apo-B100 in a sample, or for quantifying and/or recording atherogenic lipoparticles in a sample. The products, materials and kits hereinabove can also be used for differentially modulating the levels of Apo-B48 and/or Apo-B100 or their activity, in vitro or in vivo, and for regulating lipid metabolism in a subject.