Publications

Baseline thyroid-secreting-hormone (TSH)-assessed by means of ultrasensitive assays (IRMA)-and free-thyroid-hormone (FT4) levels were determined in 84 depressed females, and the TSH responses to 200 micrograms thyrotropin-releasing hormone (TRH) (IV) measured. It was found that TRH-induced TSH responses were linearly and positively related to basal TSH-IRMA; lower TRH-stimulated TSH secretion in melancholic patients was attributable to lowered basal TSH-IRMA values. A progression was found-within the euthyroid range-of basal TSH-IRMA values towards lower levels along the diagnostic spectrum: the highest basal TSH-IRMA levels were witnessed in minor depressives and the lowest in melancholics, while simple major-depressed females occupied an intermediate position. This shift appears to be indicative of severity of illness. Basal TSH-IRMA data can roughly be used as a clinical tool separating melancholia from minor depression: at a threshold value of less than or equal to 1 microUI/ml, sensitivity was 56% and specificity 92%. It is concluded that basal TSH-IRMA provides a more accurate representation of melancholia than peak TSH responses, which appear to constitute little more than a magnified, but biased signal of basal TSH-IRMA. In future, the assay of basal TSH-IRMA could replace TRH testing.

In an attempt to delineate the pathophysiology underpinning the previously reported blunted lymphocyte responses to mitogenic stimulation in depressed patients, we measured the following immune variables in 28 depressives and 10 healthy controls: pre- and postdexamethasone (1 mg orally) lymphocyte responses to various mitogens, such as phytohaemagglutinin (PHA), and the PHA-induced accumulation of interleukin-1 beta (Il-1 beta) and soluble interleukin-2-receptors (sIl-2Rs) in culture supernatants. In the predexamethasone state, we found significantly more mitogen-stimulated blastogenesis in minor depressives vs healthy controls and major depressives. In depressed subjects there was a significant inverse relationship between the severity of illness and the mitogen-induced lymphocyte responses. Melancholics exhibited significantly more Il-1 beta accumulation in PHA culture supernatant than healthy controls. In healthy controls--but not in depressed patients--the sIl-2R accumulation perfectly reflects the magnitude of the PHA-induced lymphocyte stimulation. Dexamethasone administration significantly suppressed the lectin-induced blastogenesis and the Il-1 beta production rate in normal volunteers, whereas depressives exhibited dexamethasone nonsuppression in those factors. Healthy controls exhibited significantly less postdexamethasone blast transformation, Il-1 beta and sIl-2Rs accumulation in culture supernatant than the depressed patients.

Premenstrual syndrome (PMS) frequently occurs in women of childbearing age. There are different case definitions of PMS, one proposed by the American College of Obstetricians and Gynecologists (ACOG) and another based on the Daily Record of Severity of Problems (DRSP) scores. Here we review our recent papers indicating that the discovery of biomarkers of menstrual cycle-related symptoms is strongly dependent on the case definitions used and that the gold standard methods used to asses PMS, including the ACOG case definition, induce a high degree of false-negative findings. We propose a new case definition of the menstrual cycle-associated syndrome (MCAS), which is characterized by increased DRSP scores during the menstrual cycle and additionally by an exaggerated increase in symptoms the week prior to the menses. This case definition performed well and was externally validated by diverse biomarkers including plasma levels of progesterone and estradiol, chemokines (e.g. CCL2, CCL5 and CCL11), epidermal growth factor, hydroperoxides, paraoxonase 1 activity and complement C4. In conclusion, when evaluating menstrual cycle-related symptoms and their associations with biomarkers, we propose to assess daily measurements of the DRSP and based on those scores to a) use the diagnosis of MCAS as an indicant of menstrual cycle-related symptoms; and b) examine the associations of the time series in the DRSP and its subdomains (e.g. depression, physio-somatic, anxiety) and those in biomarkers including distributed lag models.

The World Health Organization acknowledges Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) to be a medical illness. ME/CFS is characterized by disorders in the inflammatory and oxidative and nitrosative stress (IO&NS) pathways. In 2002, the Belgian government started with the development of CFS "Reference Centers", which implement a "psychosocial" model. The medical practices of these CFS Centers are defined by the Superior Health Council, e.g. treatment should be based upon Cognitive Behavioral Therapy (CBT) and Graded Exercise Therapy (GET); and biological assessments and treatments of ME/CFS should not be employed. Recently, the Belgian government has evaluated the outcome of the treatments at the CFS Centers. They concluded that a "rehabilitation therapy" with CBT/GET yielded no significant efficacy in the treatment of ME/CFS and that CBT/GET cannot be considered to be curative therapies. In case reports, we have shown that patients who were "treated" at those CFS centers with CBT/GET in fact suffered from IO&NS disorders, including intracellular inflammation, an increased translocation of gram-negative enterobacteria (leaky gut), autoimmune reactions and damage by O&NS. Considering the fact that these findings are exemplary for ME/CFS patients and that GET may even be harmful, it means that many patients are maltreated by the Belgian CFS Centers. Notwithstanding the above, the government and the CFS Centers not only continue this unethical and immoral policy, but also reinforce their use of CBT/GET in patients with ME/CFS treated at those Centers.

In schizophrenia, a single latent trait underlies psychosis, hostility, excitation, mannerism, negative (PHEMN) symptoms, formal thought disorders (FTD) and psychomotor retardation (PMR). Schizophrenia is accompanied by a breakdown of gut and blood-brain-barrier (BBB) pathways, increased tryptophan catabolite (TRYCAT) levels, bacterial translocation, and lowered natural IgM and paraoxonase (PON)1 activity. The aim of this study was to examine the factor structure of schizophrenia symptom domains and the biomarker correlates of these factors. We recruited 80 patients with schizophrenia and 40 healthy subjects and assessed the IgA/IgM responses to paracellular/transcellular (PARA/TRANS) ratios, IgA responses to TRYCATs, natural IgM to malondialdehyde and Gram-negative bacteria, and PON1 enzymatic activity.Direct Hierarchical Exploratory Factor Analysis showed a bifactorial oblique model with a) a general factor which loaded highly on all symptom domains, named overall severity of schizophrenia (“OSOS”); and b) a single-group factor (SGF) loading on negative symptoms and PMR. We found that 40% of the variance in the OSOS score was explained by IgA/IgM to PARA/TRANS ratio, male sex and education while 36.9% of the variance in SGF score was explained by IgA to PARA/TRANS, IgM to Gram-negative bacteria, female sex (positively associated) and IgM to MDA, and PON1 activity (negatively associated). Schizophrenia phenomenology comprises two biologically-validated dimensions, namely a general OSOS dimension and a single-group negative symptom dimension, which are associated with a breakdown of gut/BBB barriers, increased bacterial translocation and lowered protection against oxidation, inflammation and bacterial infections through lowered PON1 and natural IgM.