Serum levels of gamma interferon in patients with Down's syndrome

Dermatologic conditions in Down syndrome: A single-center retrospective chart review

BACKGROUND

Current literature addressing dermatologic conditions associated with Down syndrome is limited, with emphasis on rare skin conditions and lack of consensus on the incidence of more common disorders.

OBJECTIVE

We sought to evaluate dermatologic conditions in patients with Down syndrome diagnosed and managed by dermatologists.

METHODS

This was a retrospective analysis of 101 pediatric and adult patients with Down syndrome seen by the University of Massachusetts Dermatology Department between 2008 and 2018.

RESULTS

Folliculitis was the most common diagnosis overall (30.7%), followed by seborrheic dermatitis (26.7%) and hidradenitis suppurativa (22.8%). Eczematous dermatitis, alopecia areata, and xerosis were the most common diagnoses observed in children aged 0-12 years; hidradenitis suppurativa, folliculitis, and seborrheic dermatitis in adolescents aged 13-17 years; and folliculitis, seborrheic dermatitis, and xerosis in adults 18 years and older. Other notable diagnoses present overall included onychomycosis (9.9%) and psoriasis (8.9%). Malignant cutaneous tumors were present in two patients, specifically basal cell carcinoma and malignant melanoma in situ.

LIMITATIONS

This was a retrospective, single-institution study.

CONCLUSION

Dermatologic conditions in patients with Down syndrome vary by age but are most often adnexal and eczematous disorders. Trisomy of chromosome 21 and the resulting downstream effects, specifically on the immune system, may account for these findings.

Inflammation as a Modulator of Host Susceptibility to Pulmonary Influenza, Pneumococcal, and Co-Infections

Bacterial and viral pathogens are predominant causes of pulmonary infections and complications. Morbidity and mortality from these infections is increased in populations that include the elderly, infants, and individuals with genetic disorders such as Down syndrome. Immune senescence, concurrent infections, and other immune alterations occur in these susceptible populations, but the underlying mechanisms that dictate increased susceptibility to lung infections are not fully defined. Here, we review unique features of the lung as a mucosal epithelial tissue and aspects of inflammatory and immune responses in model pulmonary infections and co-infections by influenza virus and Streptococcus pneumoniae. In these models, lung inflammatory responses are a double-edged sword: recruitment of immune effectors is essential to eliminate bacteria and virus-infected cells, but inflammatory cytokines drive changes in the lung conducive to increased pathogen replication. Excessive accumulation of inflammatory cells also hinders lung function, possibly causing death of the host. Some animal studies have found that targeting host modulators of lung inflammatory responses has therapeutic or prophylactic effects in these infection and co-infection models. However, conflicting results from other studies suggest microbiota, sequence of colonization, or other unappreciated aspects of lung biology also play important roles in the outcome of infections. Regardless, a predisposition to excessive or aberrant inflammatory responses occurs in susceptible human populations. Hence, in appropriate contexts, modulation of inflammatory responses may prove effective for reducing the frequency or severity of pulmonary infections. However, there remain limitations in our understanding of how this might best be achieved—particularly in diverse human populations.

Aberrations in circulating inflammatory cytokine levels in patients with Down syndrome: a meta-analysis

Evidence suggests that immune system alterations in Down syndrome (DS) may be early events that drive neuropathological and cognitive changes of Alzheimer's disease. The primary objective of this meta-analysis was to investigate whether there is an abnormal cytokine profile in DS patients when compared with healthy control (HC) subjects. A systematic search of Pubmed and Web of Science identified 19 studies with 957 DS patients and 541 HC subjects for this meta-analysis. Random effects meta-analysis demonstrated that patients with DS had significantly increased circulating tumor necrosis factor-α (Hedges’ g = 1.045, 95% confidence interval (CI) = 0.192 to 1.898, p = 0.016), interleukin (IL)-1β (Hedges’ g = 0.696, 95% confidence CI = 0.149 to 1.242, p = 0.013), interferon-γ (Hedges’ g = 0.978, 95% CI = 0.417 to 1.539, p = 0.001) and neopterin (Hedges’ g = 0.815, 95% CI = 0.423 to 1.207, p < 0.001) levels compared to HC subjects. No significant differences were found between patients with DS and controls for concentrations of IL-4, IL-6, IL8 and IL-10. In addition, most of the cytokine data in this meta-analysis were from children with DS and HC, and subgroup analysis showed that children with DS had elevated tumor necrosis factor-α, IL-1β and interferon-γ levels when compared with controls. Taken together, these results demonstrated that patients (children) with DS are accompanied by increased circulating cytokine tumor necrosis factor-α, IL-1β and interferon-γ levels, strengthening the clinical evidence that patients (children) with DS are accompanied by an abnormal inflammatory response.

Immune-related conditions and acute leukemia in children with Down syndrome: a Children's Oncology Group report

BACKGROUND

Children with Down syndrome have unique immune profiles and increased leukemia susceptibility.

METHODS

Mothers of 158 children with Down syndrome diagnosed with acute leukemia at 0 to 19 years in 1997 to 2002 and 173 children with Down syndrome but no leukemia were interviewed. Associations were evaluated via multivariable unconditional logistic regression.

RESULTS

No associations were detected for asthma, eczema, allergies, or hypothyroidism. Diabetes mellitus associated with leukemia (OR = 9.23; 95% confidence interval 2.33-36.59); however, most instances occurred concurrent with or after the leukemia diagnosis.

CONCLUSIONS AND IMPACT

Children with Down syndrome who develop leukemia have increased diabetes risk, likely due to treatment and underlying susceptibility factors.

Cytokine dysregulation in autism spectrum disorders (ASD): possible role of the environment

Autism spectrum disorders (ASD) are neurodevelopmental diseases that affect an alarming number of individuals. The etiological basis of ASD is unclear, and evidence suggests it involves both genetic and environmental factors. There are many reports of cytokine imbalances in ASD. These imbalances could have a pathogenic role, or they may be markers of underlying genetic and environmental influences. Cytokines act primarily as mediators of immunological activity but they also have significant interactions with the nervous system. They participate in normal neural development and function, and inappropriate activity can have a variety of neurological implications. It is therefore possible that cytokine dysregulation contributes directly to neural dysfunction in ASD. Further, cytokine profiles change dramatically in the face of infection, disease, and toxic exposures. Imbalances in cytokines may represent an immune response to environmental contributors to ASD. The following review is presented in two main parts. First, we discuss select cytokines implicated in ASD, including IL-1Β, IL-6, IL-4, IFN-γ, and TGF-Β, and focus on their role in the nervous system. Second, we explore several neurotoxic environmental factors that may be involved in the disorders, and focus on their immunological impacts. This review represents an emerging model that recognizes the importance of both genetic and environmental factors in ASD etiology. We propose that the immune system provides critical clues regarding the nature of the gene by environment interactions that underlie ASD pathophysiology.

Increased pro-inflammatory cytokine production in Down Syndrome children upon stimulation with live influenza A virus

PURPOSE

Children with down syndrome (DS) have an increased susceptibility to infections, due to altered humoral and/or cellular immunity. The aim of this study was to determine the cytokine production in whole blood of children with DS upon stimulation with live influenza A virus.

METHODS

Whole blood of 61 children with DS and 57 of their healthy siblings was stimulated with 2.5 × 10(4) TCID50/ml influenza A virus during 6, 24, and 48 h. TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-12p70, IFN-α, IFN-γ concentrations, and viral load were measured at all time points.

RESULTS

At most of the time points, TNF-α, IL-1β, IL-6, and IL-8 concentrations were significantly higher in children with DS following stimulation with live influenza A virus. IFN-α and IFN-γ levels were also significantly higher in the DS group. Viral clearance, however, was equal in both groups.

CONCLUSIONS

Children with DS have an altered immune response to influenza A virus. The production of higher levels of pro-inflammatory cytokines may be responsible for a more severe clinical course of viral disease in these children.

Promotional etiology for common childhood acute lymphoblastic leukemia: the infective lymphoid recovery hypothesis

This paper speculates on the role of infection in modifying a young child's risk of promoting precursor B-cell acute lymphoblastic leukemia (ALL). It is suggested that the heat shock instigated by infections, particularly in infancy, stimulates Th1 pro-inflammatory cytokines and an apoptosis-inhibitory environment. This infective stress also increases the number of cooperating oncogenic mutations in pre-leukemic cells, especially if the primary adaptive immune response is delayed. The glucocorticoid release that follows leads to acute thymic involution, a decline in antitumor immunity, and maturation arrest of B-lymphocytes. The infective lymphoid recovery hypothesis addresses an apparent contradiction-that a non-hygienic environment primes the adaptive immune response and is protective against childhood ALL, while multiple infections occurring later increase the risk of childhood ALL. In affluent (compared to less-affluent) societies, the characteristic ALL incidence peak in early childhood, and the shortened time to diagnosis, arise from surviving recurrent infections and the accumulated loss and recovery of lymphoid tissue. Evidence supporting the hypothesis, such as the role of lymphoid tissue reconstitution cytokines that stimulate proliferation stress on B-cell progenitors, comes from the study of children with congenital syndromes that are susceptible to leukemia.

Cyclic AMP inhibition of tumor necrosis factor alpha production induced by amyloidogenic C-terminal peptide of Alzheimer's amyloid precursor protein in macrophages: involvement of multiple intracellular pathways and cyclic AMP response element binding protein

In the present study, we focused on the molecular events involved in tumor necrosis factor-alpha (TNF-alpha) production in response to the amyloidogenic 105-amino acid carboxyl-terminal fragment (CT105) of amyloid precursor protein, a candidate alternative toxic element in Alzheimer's disease pathology, and the mechanisms by which cyclic AMP regulates the relating inflammatory signal cascades. CT105 at nanomolar concentrations strongly activated multiple signaling pathways involving tyrosine kinase-dependent extracellular signal-regulated kinase and p38 mitogen-activated protein kinases. Moreover, phosphatidylinositol 3-kinase/Akt signal was required for excess TNF-alpha production in human macrophages derived from THP-1 cells. Interferon-gamma significantly potentiated the induction of the CT105-mediated signal cascade. These multiple signaling pathways in turn converged, at least in part, at the nuclear transcription factor known as cAMP response element binding protein (CREB), which acts on the TNF-alpha gene promoter through the cAMP response element. The cell-permeable cAMP analog dibutyryl cAMP partially and almost simultaneously suppressed all of these CT105-induced signaling pathways through excessive CREB phosphorylation, which led to decreased CREB DNA binding activity and reduced TNF-alpha expression. Furthermore, dibutyryl cAMP decreased the interaction of the p65 nuclear factor-kappa B with CREB binding protein, thus further inhibiting CT105-mediated TNF-alpha expression. Collectively, the detailed molecular mechanisms of amyloidogenic CT-induced TNF-alpha production as negatively regulated by cAMP may advance the possibility of targeted treatment in Alzheimer's disease.

Molecular mechanisms underlying cyclic AMP inhibition of macrophage dependent TNF-alpha production and neurotoxicity in response to amyloidogenic C-terminal fragment of Alzheimer's amyloid precursor protein

In the present study, we characterized the intracellular pathway involved in the macrophage production of tumor necrosis factor-alpha (TNF-alpha) and the molecular mechanisms by which cyclic AMP (cAMP) regulates the neurotoxic inflammatory signaling cascade in response to the 105 amino acid carboxyl-terminal fragment (CT105) of amyloid precursor protein, a candidate of alternative toxic elements in Alzheimer's disease (AD) pathology. CT105 in combination with interferon-gamma (IFN-gamma) elicited a robust and sustained increase of TNF-alpha production due to enhanced TNF-alpha mRNA transcription, mediated via increased nuclear factor-kappaB (NF-kappaB) in human macrophages derived from monocytic THP-1 cells. A mechanistic analysis revealed that the cAMP analog, dibutyryl cyclic AMP (dbcAMP), or the adenyl cyclase activator, forskolin, effectively suppressed the stimulant-induced TNF-alpha production by reducing the nuclear translocation and DNA binding activity of NF-kappaB. The inhibitory mechanisms manifested by dbcAMP included the decreased phosphorylation/degradation of NF-kappaB inhibitor (IkappaB) followed by its increased synthesis/stability. Importantly, this macrophage derived TNF-alpha appears to be a key pathological mediator of the resultant neurotoxicity, which was attenuated by increased cAMP levels during macrophage stimulation with CT105. These findings provide evidence, which supports an important role of CT105 as a potent macrophage stimulator eliciting NF-kappaB-mediated inflammatory signals for excess TNF-alpha production, which in turn ultimately leads to the neurotoxicity. In addition, the detailed inhibitory mechanism of cAMP action implies that an increased cAMP level could be benefit against AD progression.

Interferon gamma induces retrograde dendritic retraction and inhibits synapse formation

The expression of interferon gamma (IFNgamma) increases after neural injury, and it is sustained in chronic inflammatory conditions such as multiple sclerosis and infection with human immunodeficiency virus. To understand how exposure to this proinflammatory cytokine might affect neural function, we examined its effects on cultures of neurons derived from the central and peripheral nervous systems. IFNgamma inhibits initial dendritic outgrowth in cultures of embryonic rat sympathetic and hippocampal neurons, and this inhibitory effect on process growth is associated with a decrease in the rate of synapse formation. In addition, in older cultures of sympathetic neurons, IFNgamma also selectively induces retraction of existing dendrites, ultimately leading to an 88% decrease in the size of the arbor. Dendritic retraction induced by IFNgamma represents a specific cellular response because it occurs without affecting axonal outgrowth or cell survival, and it is not observed with tumor necrosis factor alpha or other inflammatory cytokines. IFNgamma-induced dendritic retraction is associated with the phosphorylation and nuclear translocation of signal transducer and activator of transcription 1 (STAT1), and expression of a dominant-negative STAT1 construct attenuates the inhibitory effect of IFNgamma. Moreover, retrograde dendritic retraction is observed when distal axons are selectively exposed to IFNgamma. These data imply that IFNgamma-mediated STAT1 activation induces both dendritic atrophy and synaptic loss and that this occurs both at the sites of IFNgamma release and at remote loci. Regressive actions of IFNgamma on dendrites may contribute to the neuropathology of inflammatory diseases.

Effects of the beta-amyloid and carboxyl-terminal fragment of Alzheimer's amyloid precursor protein on the production of the tumor necrosis factor-alpha and matrix metalloproteinase-9 by human monocytic THP-1

To explore the direct role of beta-amyloid (Abeta) and carboxyl-terminal fragments of amyloid precursor protein in the inflammatory processes possibly linked to neurodegeneration associated with Alzheimer's disease, the effects of the 105-amino acid carboxyl-terminal fragment (CT(105)) of amyloid precursor protein on the production of tumor necrosis factor-alpha (TNF-alpha) and matrix metalloproteinase-9 (MMP-9) were examined in a human monocytic THP-1 cell line and compared with that of Abeta. CT(105) elicited a marked increase in TNF-alpha and MMP-9 production in the presence of interferon-gamma in a dose- and time-dependent manner. Similar patterns were obtained with Abeta despite its low magnitude of induction. Autocrine TNF-alpha is likely to be a main mediator of the induction of MMP-9 because the neutralizing antibody to TNF-alpha inhibits MMP-9 production. Genistein, a specific inhibitor of tyrosine kinase, dramatically diminished both TNF-alpha secretion and subsequent MMP-9 release in response to CT(105) or Abeta. Furthermore, PD98059 and SB202190, specific inhibitors of ERK or p38 MAPK respectively, efficiently suppressed CT(105)-induced effects whereas only PD98059 was effective at reducing Abeta-induced effects. Our results suggest that CT(105) in combination with interferon-gamma might serve as a more potent activator than Abeta in triggering inflammatory processes and that both tyrosine kinase and MAPK signaling pathways may represent potential therapeutic targets for the control of Alzheimer's disease progression.

Evidence for an interferon-related inflammatory reaction in the trisomy 16 mouse brain leading to caspase-1-mediated neuronal apoptosis

The trisomy of human chromosome 21 (Down syndrome) is the leading genetic cause of learning difficulties in children, and predisposes this population to the early onset of the neurodegeneration of Alzheimer's disease. Down syndrome is associated with increased interferon (IFN) sensitivity resulting in unexpectedly high levels of IFN inducible gene products including Fas, complement factor C3, and neuronal HLA I which could result in a damaging inflammatory reaction in the brain. Consistent with this possibility, we report here that the trisomy 16 mouse fetus has significantly increased whole brain IFN-gamma and Fas receptor immunoreactivity and that cultured whole brain trisomy 16 mouse neurons have increased basal levels of caspase 1 activity and altered homeostasis of intracellular calcium and pH. The trisomic neurons also showed a heightened sensitivity to the increase in both Fas receptor levels and caspase 1 activity we observed when IFN-gamma was added to the neuron culture media. Because of the autoregulatory nature of IFN activity, and the IFN inducing capability of caspase-1-activated cytokine activity, our data argue in favor of the possibility of an interferon-mediated, self-perpetuating, inflammatory response in the trisomy brain that could subserve the loss of neuron viability seen in this trisomy 16 mouse model for Down syndrome.