Publications by authors named "Leon Karp"

Objective: Previous studies suggest that selective serotonin reuptake inhibitors (SSRIs) modulate immune system functionality. SSRIs are the preferred treatment for major depressive disorder (MDD). A high rate of MDD is observed in rheumatoid arthritis (RA) patients.

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A variety of psychiatric illnesses, including schizophrenia and bipolar disorder, have been reported in patients with microdeletion on chromosome 22q11-a region which includes the catechol-O-methyltransferase (COMT) gene. The variety of psychiatric manifestations in patients with the 22q11 microdeletion and the role of COMT in the degradation of catecholamine neurotransmitters may thus suggest a general involvement of the COMT gene in psychiatric diseases. We have previously reported on a significant association between a COMT haplotype and schizophrenia.

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The peripheral blood platelets of schizophrenic patients were isolated, and the level of the platelet-associated antibodies (SPAA) was correlated with the rating scores of discrete schizophrenic symptom clusters evaluated with the Brief Psychiatric Rating Scale. Irrespective of medication and gender, symptom-dependent correlations were established between the SPAA levels and the relevant psychometric scores. The results indicate a heterogeneous origin of schizophrenia and imply the involvement of an autoimmune arm as a predominantly protective immune response.

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Several lines of evidence have placed the catechol-O-methyltransferase (COMT) gene in the limelight as a candidate gene for schizophrenia. One of these is its biochemical function in metabolism of catecholamine neurotransmitters; another is the microdeletion, on chromosome 22q11, that includes the COMT gene and causes velocardiofacial syndrome, a syndrome associated with a high rate of psychosis, particularly schizophrenia. The interest in the COMT gene as a candidate risk factor for schizophrenia has led to numerous linkage and association analyses.

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