Brain functional impairment in beta-thalassaemia: the cognitive profile in Italian neurologically asymptomatic adult patients in comparison to the reported literature.

Abstract

Cognitive involvement in beta-thalassaemia is strikingly controversial and poorly studied in adulthood. This multicentre prospective study investigated 74 adult neurologically-asymptomatic beta-thalassaemia patients (mean-age 34·5±10·3years; 53 transfusion-dependent [TDT], 21 non-transfusion dependent [NTDT]) and 45 healthy volunteers (mean-age 33·9±10·7years). Participants underwent testing with Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV), Brief Psychiatric Rating Scale (BPRS) and multiparametric brain 3T-magnetic resonance imaging (MRI) for parenchymal, vascular and iron content evaluation. Patients had lower Full-Scale Intelligence Quotient (FSIQ) than controls (75·5±17·9 vs. 97·4±18·1, P<0·0001) even after correction for education level. Compared to TDT, NTDT showed a trend of higher FSIQ (P=0·08) but a similar cognitive profile at WAIS-subtests. FSIQ correlated with total and indirect bilirubin (P<0·0001 and P=0·002, respectively); no correlation was found with splenectomy, intracranial MRI/magnetic resonance-angiography findings, brain tissue iron content or other disease-related clinical/laboratory/treatment data. FSIQ did not correlate with BPRS scores, although the latter were higher among patients (28·74±3·1 vs. 27·29±4·8, P=0·01) mainly because of increased depression and anxiety levels. Occupation rate was higher among controls (84·4% vs. 64·9%, P=0·004) and correlated with higher FSIQ (P=0·001) and education level (P=0·001). In conclusion, Italian adult beta-thalassaemia patients seem to present a characteristic cognitive profile impairment and an increased rate of psychological disorders with possible profound long-term socio-economic consequences.