Background: A meaningful part of schizophrenia patients suffer from physiosomatic symptoms (formerly named psychosomatic) which are reminiscent of chronic fatigue syndrome and fibromyalgia (FF) and are associated with signs of immune activation and increased levels of tryptophan catabolites (TRYCATs). Aims: To examine whether FF symptoms in schizophrenia are associated with breakdown of the paracellular pathway, zonulin, lowered natural IgM responses to oxidative specific epitopes (OSEs); and whether FF symptoms belong to the behavioral-cognitive-physical-psychosocial-(BCPS)-worsening index consisting of indices of a general cognitive decline (G-CoDe), symptomatome of schizophrenia, and quality of life (QoL)-phenomenome. Methods: FF symptoms were assessed using the Fibromyalgia and Chronic Fatigue Rating scale in 80 schizophrenia patients and 40 healthy controls and serum cytokines/chemokines, IgA levels to TRYCATs, IgM to OSEs, zonulin and transcellular/paracellular (TRANS/PARA) molecules were assayed using ELISA methods. Results: A large part (42.3%) of the variance in the total FF score was explained by the regression on the PARA/TRANS ratio, pro-inflammatory cytokines, IgM to zonulin, IgA to TRYCATs (all positively) and IgM to OSEs (inversely). There were highly significant correlations between the total FF score and G-CoDe, symtopmatome, QoL phenomenome and BCPS-worsening score. FF symptoms belong to a common core shared by G-CoDe, symtopmatome, and QoL phenomenome. Discussion: The physio-somatic symptoms of schizophrenia are driven by various pathways including increased zonulin, breakdown of the paracellular tight-junctions pathway, immune activation with induction of the TRYCAT pathway, and consequent neurotoxicity. It is concluded that FF symptoms are part of the phenome of schizophrenia and BCPS-worsening as well.

Introduction: Increased oxidative stress, including elevated homocysteine (Hcy) plasma levels, and lowered levels of antioxidants participate in the pathophysiology and progression of chronic kidney disease (CKD). Paraoxonase (PON)1 activity and folic acid are antioxidants which play a role in Hcy metabolism. However, there are no data whether, in CKD, treatment with folic acid improves glomerular filtration rate (GFR) through effects on PON1 activity and Hcy concentrations. Methods: In the current study, we determined PON1 genotypes and activity, Hcy and estimated GFR (eGFR) both before and after treatment with folic acid (5 mg/d) versus no treatment during three consecutive months in 113 outpatients with CKD classified into stages 4, 3b and 3a. Results: PON1 CMPAase and AREase activities were significantly lower in patients allocated to CKD stage 4 as compared with stages 3b and 3a. Treatment with folic acid significantly improved eGFR and increased levels of CMPAase and AREase in patients allocated to classes 4 and 3b, but not 3a. The improvement of eGFR was associated with increased CMPAase and AREase activities, while the latter were associated with increased levels of folic acid. Treatment with folic acid significantly reduced plasma Hcy levels and the Hcy/PON1 activity ratio. The effects of folic acid increasing PON1 activities were not mediated by changes in Hcy. Discussion: Treatment of CKD patients in early/intermediate stages of CKD patients improves oxidative stress by rebalancing the prooxidant (Hcy) / antioxidant (PON1 activities) ratio. Treatment with folic acid significantly improves eGFR and these effects are mediated via increased PON1 activities. Treatment with folic acid in phase G3b and G4 may reduce renal disease progression by enhancing antioxidant defenses.