Atherosclerosis 131 (1997) 127 – 133 Plasma lipoprotein composition, apolipoprotein(a) concentration and isoforms in  -thalassemia Mario Maioli a , Giovanni B. Vigna b , Giancarlo Tonolo a , Patrizia Brizzi a , Milco Ciccarese a , Paola Donega ` b , Margherita Maioli c, *, Renato Fellin b a Institute of Internal Medicine, Uniersity of Sassari, Sassari, Italy b Institute of Internal Medicine 2, Uniersity of Ferrara, Ferrara, Italy c Institute of Biochemistry, Uniersity of Sassari, iale S. Pietro, 8, 07100 Sassari, Italy Received 28 December 1996; received in revised form 31 January 1997; accepted 10 February 1997 Abstract Patients with homozygous  -thalassemia show an abnormal lipoprotein profile. In asymptomatic heterozygotes the lipid pattern is less markedly affected but interestingly related to a diminished cardiovascular risk. The extent and significance of these findings are still a matter of debate and no data are available on lipoprotein(a) plasma levels. Seventy patients with homozygous  -thalassemia (HT-P), 70  -thalassemia trait carriers (TT-C) and 70 sex and age-matched controls were investigated and their plasma lipoprotein profile and apo(a) phenotypes determined. In a subgroup of these same subjects (12 HT-P, 12 TT-C and 24 controls) and in 12 bone marrow-transplanted homozygous  -thalassemic patients (BMT-P) plasma lipoprotein composition was assessed. HT-P disclosed significantly lower total-cholesterol, LDL-cholesterol, HDL-cholesterol, apo A-I, apo B plasma levels and higher triglyceride concentration than TT-C ( -7, -11, -8, -8, -13 and +11%, respectively) or controls ( -39, -50, -46, -32, -30 and +35%, respectively). All lipoprotein subclasses were triglyceride-enriched, while LDLs were also protein-enriched and HDLs protein-depleted. TT-C disclosed a small but significant reduction in apo A-I and apo B plasma levels but only minor lipoprotein abnormalities with respect to the controls. BMT-P lipoprotein composition was intermediate between HT-P and normal subjects. Apo(a) plasma levels did not differ among the groups. A higher prevalence of ‘small’ apo(a) isoforms was present in HT-P. Within the same ‘isoform group’, apo(a) plasma levels were significantly lower in HT-P than in TT-C or controls. Since liver cirrhosis is almost always present in HT-P, it is conceivable that an altered hepatic apo(a) synthesis or catabolism due perhaps to diminished apolipoprotein glycation may be involved. In TT-C a partially improved cardiovascular risk profile was apparent (low hematocrit, low LDL-cholesterol and apo B), thus justifying the claim for a low prevalence of ischemic heart disease, but no Lp(a) plasma level modification could be detected. © 1997 Elsevier Science Ireland Ltd. Keywords:  -Thalassemia; Anemia; Lipoproteins; Cholesterol; Apolipoprotein(a); Isoforms 1. Introduction  -Thalassemia, an inherited disease of hemoglobin  -chain synthesis characterized by ineffective erythro- poiesis and hemolysis [1], shows striking geographical differences in prevalence (up to 30% of the respective population, particularly in the Mediterranean area). In the homozygous form of this disorder (Cooley‘s disease), anemia and hemolysis are prominent; patients thus need continuous transfusions which lead to con- comitant tissue hemosiderosis (also related to increased enteric iron absorption), hepatic fibrosis and eventually cirrhosis [2]. If appropriate treatment is not instituted early in life the outcome is ultimately fatal. On the other hand, heterozygous  -thalassemia ( -trait carrier state) is a mild microcytic anemia without significant clinical manifestations [3]. Mortality is not increased, and a low prevalence of several common diseases, * Corresponding author. Tel./fax: +39 79 228240. 0021-9150/97/$17.00 © 1997 Elsevier Science Ireland Ltd. All rights reserved. PII S0021-9150(97)06095-4