ABCB1 gene variants influence tolerance to selective serotonin reuptake inhibitors in a large sample of Dutch cases with major depressive disorder.

P-glycoprotein (P-gp), an ATP-driven efflux pump in the blood-brain barrier, has a major impact on the delivery of antidepressant drugs in the brain. Genetic variants in the gene ABCB1 encoding for P-gp have inconsistently been associated with adverse effects. In order to resolve these inconsistencies, we conducted a study in a large cohort of patients with major depressive disorder with the aim to unravel the association of ABCB1 variants with adverse effects of antidepressants and in particular with selective serotonin reuptake inhibitors (SSRIs), which display affinity as substrate for P-gp. The Netherlands Study of Depression and Anxiety (NESDA) study was used as a clinical sample. For 424 patients data were available on drug use, side effects. We selected six ABCB1 gene variants (1236T>C, 2677G>T/A, 3435T>C, rs2032583, rs2235040 and rs2235015) and analyzed them for association with adverse drug effects using multinomial regression analysis for both single variants and haplotypes. We found a significant association between the number of SSRI-related adverse drug effects and rs2032583 (P=0.001), rs2235040 (P=0.002) and a haplotype (P=0.002). Moreover, serotonergic effects (sleeplessness, gastrointestinal complaints and sexual effects) were significantly predicted by these variants and haplotype (P=0.002/0.003). We conclude that adverse drug effects with SSRI treatment, in particular serotonergic effects, are predicted by two common polymorphisms of the ABCB1 gene.

11C-verapamil to assess P-gp function in human brain during aging, depression and neurodegenerative disease.

P-glycoprotein (P-gp) at the blood-brain barrier (BBB) functions as an active efflux pump by extruding a wide range of substrates from the brain. This is important for maintaining loco-regional homeostasis and for protecting the brain against blood-borne toxic substances. Altered P-gp function seems to be involved in the pathophysiology of neurodegenerative disease and various neurological and psychiatric disorders. Positron emission tomography (PET) with the radiotracer (11)C-verapamil (VPM-PET) is a validated technique allowing measurement of P-gp function at the human BBB. In this review, we highlight changes of P-gp function, as measured with VPM-PET, in aging and in the pathogenesis and progression of neurodegenerative disease, as well as their role in depressive disorders.

An unusual cause of neonatal seizures in a newborn infant.

Neonatal seizures in the neonatal period are symptoms of numerous underlying disorders of the neonate. We present a case in which neonatal seizures due to cerebral infarction led to a diagnosis in the mother. Neonatal convulsions caused by cerebral artery thrombosis is relatively rare in the neonatal period and is often secondary to indwelling intravascular catheters that cause thromboembolism, but may be associated with many conditions.1 Cerebral artery thrombosis in newborns, in which antiphospholipid antibodies (APA) were found in the mother, has been described in three case reports. Two of these premature infants were born with other risk factors for thrombosis. APA could not be identified in any of these three infants. In the two cases reported by Silver et al the diagnosis was made several months after birth. This case is unique in the fact that no other risk factors for thrombosis could be identified to explain the infarction, and that APA were found in the offspring of an apparently healthy mother. Whether the prior fetal death was caused by APA remains unclear. The finding of lupus anticoagulant in her child led to the diagnosis of antiphospholipid antibody syndrome in her. We believe that in case of cerebral artery thrombosis in a neonate, with no trivial cause such as an indwelling catheter or sepsis, both mother and infant should be tested for presence of APA, even when the mother seems healthy.