Prednisone effects on blood-brain barrier permeability and CNS IgG synthesis in healthy humans

Treatment and protective effects of metalloproteinase inhibitors alone and in combination with N-Acetyl cysteine plus vitamin E in rats exposed to aflatoxin B1

This study was conducted to investigate the effects of matrix metalloproteinase (MMP) inhibitors dexamethasone and minocycline administrations -both single and in combination with N-acetylcysteine (NAC) and vitamin E-on the tissue distribution and lethal dose (LD)₅₀ of aflatoxin (AF)B₁ in rats. We performed this study on male Wistar rats (8-10 weeks) in two phases. In the first phase, rats were administered dexamethasone (5 and 20 mg/kg) and minocycline (45 and 90 mg/kg), both as single treatments and in combination with NAC (200 mg/kg) and vitamin E (600 mg/kg); these treatments followed AFB₁ administration (2 mg/kg). In the second phase, the therapeutic effect value (TEV) was calculated to determine the treatment effect on the LD₅₀ level of AFB₁. The tissue affinity of AFB1 from high to low was liver, kidney, intestine, brain, heart, spleen, lung, testis, and vitreous humor, respectively. Dexamethasone at the 20 mg/kg dose significantly reduced AFB₁ concentrations in the plasma and the other tissues, except for the vitreous humor. The effects of minocycline on the plasma and tissue concentrations of AFB₁ varied by dose and tissue. The combinations of dexamethasone or minocycline with NAC and vitamin E increased the AFB₁ concentrations in the plasma and all tissues, except for vitreous humor and liver. In male rats, the LD₅₀ value of AFB₁ was 11.86 mg/kg. The TEV of dexamethasone (20 mg/kg) was calculated to be 1.5. Dexamethasone can be administered in repeated doses at ≥20 mg/kg to increase survival in AFB₁ poisoning.

What does plasma CRP tell us about peripheral and central inflammation in depression?

Peripheral blood C-reactive protein (CRP) is a biomarker used clinically to measure systemic inflammation and is reproducibly increased in a subset of patients with major depressive disorder (MDD). Furthermore, increased peripheral blood CRP in MDD has been associated with altered reward circuitry and increased brain glutamate in relation with symptoms of anhedonia. Nevertheless, the relationship between peripheral CRP and other peripheral and central markers of inflammation in depressed patients has not been established. Plasma (n = 89) and CSF (n = 73) was collected from medically stable, currently unmedicated adult outpatients with MDD. Associations among plasma and CSF CRP and plasma and CSF inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF] and IL-1beta) and their soluble receptors/antagonists were examined. Relationships between plasma and CSF inflammatory markers and depressive symptoms including anhedonia and reduced motivation (RM) were also explored. Plasma CRP was correlated with multiple plasma inflammatory markers (all p < 0.05), and a strong correlation was found between plasma and CSF CRP (r = 0.855, p < 0.001). CSF CRP in turn correlated with CSF cytokine receptors/antagonists (all p < 0.05). Principal component analyses revealed clusters of CSF inflammatory markers that were associated with high plasma CRP (>3 mg/L) and correlated with depressive symptom severity. These findings were driven by CSF TNF, which correlated with RM (r = 0.236, p = 0.045), and CSF IL-6 soluble receptor, which correlated with anhedonia (r = 0.301, p = 0.010) in the sample as a whole and particularly females. CRP appears to be a peripheral biomarker that reflects peripheral and central inflammation and seems well-suited for guiding immunotherapies targeting TNF and IL-6 in patients with MDD.

Selective Subnormal IgG1 in 54 Adult Index Patients with Frequent or Severe Bacterial Respiratory Tract Infections

We characterized 54 adult index patients with reports of frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG1. Mean age was 50 ± 13 (SD) y; 87.0% were women. Associated disorders included the following: autoimmune conditions 50.0%; hypothyroidism 24.1%; atopy 38.9%; and other allergy 31.5%. In 35.5%, proportions of protective S. pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination (PPPV). Blood lymphocyte subset levels were within reference limits in most patients. Regressions on IgG1 and IgG3 revealed no significant association with age, sex, autoimmune conditions, hypothyroidism, atopy, other allergy, corticosteroid therapy, or lymphocyte subsets. Regression on IgG2 revealed significant associations with PPPV response (negative) and CD19+ lymphocytes (positive). Regression on IgG4 revealed significant positive associations with episodic corticosteroid use and IgA. Regression on IgA revealed positive associations with IgG2 and IgG4. Regression on IgM revealed negative associations with CD56+/CD16+ lymphocytes. Regressions on categories of infection revealed a negative association of urinary tract infections and IgG1. HLA-A^⁎03, HLA-B^⁎55 and HLA-A^⁎24, HLA-B^⁎35 haplotype frequencies were greater in 38 patients than 751 controls. We conclude that nonprotective S. pneumoniae IgG levels and atopy contribute to increased susceptibility to respiratory tract infections in patients with selective subnormal IgG1.

Selective subnormal IgG3 in 121 adult index patients with frequent or severe bacterial respiratory tract infections

We characterized 121 adults with frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG3. Mean age was 47 ± 13 (SD)y; 87.6% were women. Associated disorders included: autoimmune conditions 33.1%; hypothyroidism 14.9%; atopy 29.8%; and other allergy manifestations 41.3%. In 34.1%, proportions of protective Streptococcus pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination. Blood CD19+, CD3+/CD4+, CD3+/CD8+, and CD56+/CD16+ lymphocyte levels were within reference limits in most patients. In regression analyses, independent variables age; sex; autoimmune conditions; hypothyroidism; atopy; allergy manifestations; corticosteroid therapy; and lymphocyte subsets were not significantly associated with IgG subclass, IgA, or IgM levels. Frequencies of HLA haplotypes A*01, B*08; A*02, B*14; A*02, B*15; A*02, B*44; A*02, B*57; and A*03, B*07 were greater in 80 patients than 751 controls. We conclude that subnormal IgG3 and non-protective S. pneumoniae IgG levels contribute to increased susceptibility to respiratory tract infections.

Gonadotropin, ACTH, prolactin, sexual steroid and cortisol levels in postmenopausal women's cerebrospinal fluid (CSF)

In CSF and serum of 24 fertile (34.9 +/- 12.2 years) and 15 postmenopausal (58.9 +/- 6.9 years) female patients with non-inflammatory neurologic diseases, LH, FSH, ACTH, prolactin (Prol), estradiol (E), progesterone (P), testosterone (T), and cortisol (C) levels were determined by RIA. In postmenopause, serum levels of FSH and LH had 8- and 6-fold increases in comparison to those in reproductive age. In postmenopause, serum levels of E, P, ACTH and Prol had 8-, 5-, 3- and 2-fold decreases. Serum levels of T and C remained statistically unchanged during the whole life span. In postmenopause, CSF levels of FSH and LH had 3- and 2-fold increases, while E, P, Prol, ACTH CSF levels remained statistically unchanged compared to those in reproductive age (CSF-C levels were under the test sensitivities). CSF/serum ratio of FSH had a 4-fold decrease while that of E had a 4-fold increase in the postmenopause. CSF and serum levels of estradiol and ACTH as well as the logarithmic values of FSH, Prol and P concentrations correlated significantly regarding the whole reproductive postmenopausal life span, however, the CSF-blood barrier seemed to protect the brain from the effects of peripheral estradiol-progesterone deficiencies.