Specific glycosylation of alpha(1)-acid glycoprotein characterises patients with familial Mediterranean fever and obligatory carriers of MEFV

Glycoprotein analysis using lectin microcolumns and capillary electrophoresis: Characterization of alpha1-acid glycoprotein by combined separation methods

Separations based on combinations of 2.1 mm I.D. high-performance affinity microcolumns and capillary electrophoresis were developed and used to characterize the glycoforms of an intact glycoprotein. Human alpha₁-acid glycoprotein (AGP) was used as a model analyte due to its heterogeneous glycosylation resulting from variations in its degree of branching, fucosylation, and number of sialic acids. Three separation formats were examined based on microcolumns that contained the lectins concanavalin A (Con A) or Aleuria aurantia lectin (AAL). These microcolumns were used with one another or in combination with capillary electrophoresis. N-Glycan analysis of the non-retained and retained AGP fractions was carried out by using PNGase F digestion and nanoflow electrospray ionization mass spectrometry. Con A microcolumns were found to selectively enrich AGP that contained bi-antennary N-glycans, while AAL microcolumns retained AGP with fucose-containing N-glycans. Results from these separation methods indicated that fucosylation of the N-linked glycans was more abundant when a high degree of branching was present in AGP. Sialic acid residues were more abundant when higher degrees of branching and more fucose residues were present in AGP. The separation and analysis methods that were developed could be used with relatively small amounts of AGP and can be adapted for use with other intact glycoproteins.

Is There a Long-Term Risk for Donors With Heterozygous MEFV Mutation After Kidney Donation?

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal-recessive autoinflammatory disorder manifested severely by systemic amyloidosis. It has been hypothesized that heterozygous carriers may also have susceptibility to certain symptoms or even diseases. Because the living kidney donors of patients with FMF are generally relatives of the kidney recipients, there is a high possibility that the donors will have a heterozygous mutation of the FMF gene. The goal of this study was to investigate the long-term kidney function of donors who are carriers of the Mediterranean fever (MEFV) gene.

METHODS

The medium- to long-term outcomes of 12 asymptomatic donors were compared with MEFV gene carriers and 24 non-FMF recipients' donors.

RESULTS

Heterozygous carriers and the control group were similar with respect to age, sex, and follow-up period. The preoperative estimated glomerular filtration rate and 24-hour urine proteinuria levels were similar in the MEFV carrier and control groups. Four years after the donation, both groups had similar estimated glomerular filtration rates, but the change in 24-hour urine protein was statistically higher in the MEFV carrier group, and no significant change was observed in the control group (P = .004). At the end of the follow-up period, neither overt proteinuria nor kidney failure was seen in either group.

CONCLUSIONS

This study showed that the medium- to long-term results of the kidney donors who are carriers of the MEFV gene seem to be safe. However, there was more of a tendency for an increase in proteinuria in the MEFV gene carriers compared with control subjects, which necessitated further long-term care for these donors.

Cytokines and chemokines: At the crossroads of cell signalling and inflammatory disease

Inflammation occurs as a result of exposure of tissues and organs to harmful stimuli such as microbial pathogens, irritants, or toxic cellular components. The primary physical manifestations of inflammation are redness, swelling, heat, pain, and loss of function to the affected area. These processes involve the major cells of the immune system, including monocytes, macrophages, neutrophils, basophils, dendritic cells, mast cells, T-cells, and B-cells. However, examination of a range of inflammatory lesions demonstrates the presence of specific leukocytes in any given lesion. That is, the inflammatory process is regulated in such a way as to ensure that the appropriate leukocytes are recruited. These events are in turn controlled by a host of extracellular molecular regulators, including members of the cytokine and chemokine families that mediate both immune cell recruitment and complex intracellular signalling control mechanisms that characterise inflammation. This review will focus on the role of the main cytokines, chemokines, and their receptors in the pathophysiology of auto-inflammatory disorders, pro-inflammatory disorders, and neurological disorders involving inflammation.

TLR-4 polymorphisms and leukocyte TLR-4 expression in febrile UTI and renal scarring

BACKGROUND

In this study, we aimed to determine the relation of TLR-4 Asp299Gly and Thr399Ile polymorphisms and monocyte/neutrophil TLR-4 expression to febrile urinary tract infection (UTI) and renal scar development in children.

METHODS

The study was performed in children with a history of febrile UTI. Patients with and without renal scarring were classified as group 1 and group 2, respectively, while the control cases in our previous study were used as the control group (group 3). All three groups were compared for the rate of TLR-4 Asp299Gly and Thr399Ile polymorphisms, and for basal and lipopolysaccharide-stimulated monocyte/neutrophil TLR-4 expression levels.

RESULTS

There were 168 patients (86 in group 1, 82 in group 2) and 120 control cases. Monocyte/neutrophil TLR-4 expression levels were similar in groups 1 and 2. However, both groups had lower TLR-4 expression than group 3. The rate of TLR-4 Asp299Gly polymorphism was not different in all groups. TLR-4 Thr399Ile polymorphism was higher in groups 1 and 2 than in group 3 (14.0, 12.2, and 2.0 %, respectively), while group 1 and group 2 were not different. Furthermore, monocyte TLR-4 expression level was lower in those having TLR-4 Thr399Ile polymorphism than in those without this polymorphism.

CONCLUSIONS

Patients with febrile UTI had more frequent TLR-4 Thr399Ile polymorphism and lower monocyte/neutrophil TLR-4 expression. These findings indicate that children carrying TLR-4 Thr399Ile polymorphism and/or having low level of monocyte/neutrophil TLR-4 expression have a tendency to develop febrile UTI. However, we could not show the association of TLR-4 polymorphisms and of TLR-4 expression level to renal scarring.

Relationship between serum interleukin-1beta levels and acute phase response proteins in patients with familial Mediterranean fever

Introduction:

The aim of this study was to investigate whether serum levels of interleukin-1β (IL–1β) has any possible correlation on inflammatory parameters such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fibrinogen concentration in patients with familial Mediterranean fever (FMF) patients during attack-free period.

Materials and methods:

The serum levels of IL-1β, as an indicator of cytokines status, and the acute phase response proteins, CRP, ESR and fibrinogen levels were evaluated in 35 attack-free patients with FMF and 25 healthy volunteers.

Results:

Serum IL-1β levels were significantly higher in patients with FMF than control subjects (P = 0.018). There was no statistically significant difference in the serum levels of ESR, CRP and fibrinogen between two groups (P = 0.181, P = 0.816, P = 0.686, respectively). There was a significant correlation between IL-1β and CRP (r = 0.513, P = 0.002) values of FMF group.

Conclusions:

In conclusion, our results confirm the presence of increased IL-1β levels in FMF patients during attack-free period. Serum IL-1β values seems to correlate with CRP levels. The elevation of IL-1β levels may be important in monitoring subclinical inflammation of attack free period in FMF patients.

Predominant role of host genetics in controlling the composition of gut microbiota

Background

The human gastrointestinal tract is inhabited by a very diverse symbiotic microbiota, the composition of which depends on host genetics and the environment. Several studies suggested that the host genetics may influence the composition of gut microbiota but no genes involved in host control were proposed. We investigated the effects of the wild type and mutated alleles of the gene, which encodes the protein called pyrin, one of the regulators of innate immunity, on the composition of gut commensal bacteria. Mutations in MEFV lead to the autoinflammatory disorder, familial Mediterranean fever (FMF, MIM249100), which is characterized by recurrent self-resolving attacks of fever and polyserositis, with no clinical signs of disease in remission.

Methodology/Principal Findings

A total of 19 FMF patients and eight healthy individuals were genotyped for mutations in the MEFV gene and gut bacterial diversity was assessed by sequencing 16S rRNA gene libraries and FISH analysis. These analyses demonstrated significant changes in bacterial community structure in FMF characterized by depletion of total numbers of bacteria, loss of diversity, and major shifts in bacterial populations within the Bacteroidetes, Firmicutes and Proteobacteria phyla in attack. In remission with no clinical signs of disease, bacterial diversity values were comparable with control but still, the bacterial composition was substantially deviant from the norm. Discriminant function analyses of gut bacterial diversity revealed highly specific, well-separated and distinct grouping, which depended on the allele carrier status of the host.

Conclusions/Significance

This is the first report that clearly establishes the link between the host genotype and the corresponding shifts in the gut microbiota (the latter confirmed by two independent techniques). It suggests that the host genetics is a key factor in host-microbe interaction determining a specific profile of commensal microbiota in the human gut.

Fucosylation of serum α1-acid glycoprotein in rheumatoid arthritis patients treated with infliximab

To analyze fucosylation of alpha(1)-acid glycoprotein (AGP) and to identify relations between AGP fucosylation and clinical and biochemical indices of disease activity in patients with rheumatoid arthritis (RA) treated with monoclonal antitumor necrosis factor (TNF) antibody infliximab, we examined 22 patients with RA who underwent a 54-week treatment with infliximab according to ATTRACT protocol. Blood samples were collected at baseline and before every infusion of infliximab. AGP fucosylation was measured using lectin-binding enzyme-linked immunosorbent assay utilizing fucose-specific lectin Aleuria aurantia (AAL). Moreover, the clinical status/activity, erythrocyte sedimentation rate, serum C-reactive protein (CRP), antitrypsin, alpha(1)-antichymotrypsin, AGP reactivity with concanavalin A, serum C3 and C4 complement components, and serum concentrations of TNF and soluble TNF type 1 and type 2 receptors were determined. In most patients, the fucosylation of AGP decreased rapidly after first infusion of infliximab and remained low during the 54-week therapy (p < 0.001). The decrease in AGP affinity to AAL closely followed changes in clinical and laboratory activity of RA and correlated with pretreatment concentrations of CRP (r = 0.4986, p < 0.05) and TNF (r = 0.5181, p < 0.05). The fucosylation of AGP can be a part of a negative feedback loop regulating migration of inflammatory cells and collagenase-3 activity in RA. The decrease in AGP fucosylation accompanied by improvement in clinical and biochemical parameters of RA could possibly reflect reduced migration of inflammatory cells to inflamed joints and AGP-mediated inhibition of collagenase-3 as a response to infliximab treatment.

CATERPILLERs, pyrin and hereditary immunological disorders

The newly described CATERPILLER family (also known as NOD-LRR or NACHT-LRR) is comprised of proteins with a nucleotide-binding domain and a leucine-rich region. This family has gained rapid prominence because of its demonstrated and anticipated roles in immunity, cell death and growth, and diseases. CATERPILLER proteins are structurally similar to a subgroup of plant-disease-resistance (R) proteins and to the apoptotic protease activating factor 1 (APAF1). They provide positive and negative signals for the control of immune and inflammatory responses, and might represent intracellular sensors of pathogen products. Most importantly, they are genetically linked to several human immunological disorders.

The familial Mediterranean fever (MEVF) gene as a modifier of Crohn's disease

OBJECTIVES

Crohn's disease (CD) has been reported to be more frequent among non-Ashkenazi Jewish patients suffering from familial Mediterranean fever (FMF). Interestingly, functional similarities between the CD susceptibility gene (NOD2/CARD15) and the FMF gene (MEFV) have been described: both belong to the death domain containing protein family, important in the regulation of apoptosis, cytokine processing and inflammation.

AIMS

To investigate the prevalence of MEFV mutations in Jewish non-Ashkenazi CD patients and its putative effect on CD presentation.

METHODS

Germline DNA of 105 Israeli CD patients of non-Ashkenazi and mixed Ashkenazi-non-Ashkenazi ethnic background was analyzed for three most common MEFV mutations: M694V, V726A, and E148Q. Five patients (4.7%) with a clinical diagnosis of FMF were included. Data obtained from each patient included: age of onset, disease location, and behavior, the presence of extraintestinal manifestations of CD and therapeutic regimens.

RESULTS

The overall prevalence of mutation carriers among non-FMF-CD patients was 13% (13/100). A stricturing disease pattern was observed in 56% (10/18) of all carriers, FMF-CD, and non-FMF-CD patients, and in 25% (22/87) of noncarriers (OR: 3.7, 95% CI: 1.3-10.5, p= 0.015). The prevalence of fistulas was comparable in both groups. Extraintestinal manifestations were significantly more frequent among carriers than noncarriers (65%vs 32%, OR 3.9, 95% CI = 1.3-11.5, p= 0.015). No differences were observed in disease location and disease severity.

CONCLUSIONS

MEFV mutations are not associated with CD susceptibility, yet the presence of these mutations appears to be associated with a stricturing disease pattern and extraintestinal disease manifestations of CD.

Effect of inflammatory attacks in the classical type hyper-IgD syndrome on immunoglobulin D, cholesterol and parameters of the acute phase response

BACKGROUND

Classical type hyper-immunoglobulin D (IgD) syndrome (HIDS) is an hereditary auto-inflammatory disorder, characterized by recurrent episodes of fever, lymphadenopathy, abdominal distress and a high serum concentration of IgD. It is caused by mevalonate kinase deficiency.

OBJECTIVE

To further characterize the acute phase response during fever attacks in HIDS in order to improve diagnosis.

SUBJECTS

Twenty-two mevalonate kinase-deficient HIDS patients.

METHODS

Blood samples were drawn during and in between febrile attacks, and concentrations ofC-reactive protein (CRP), ferritin, procalcitonin, pentraxin 3, IgD and cholesterol in several lipoprotein fractions were determined.

RESULTS

The marked acute phase response at the time of a fever attack in classical type HIDS is reflected by a rise in CRP accompanied by a moderate but statistically significant rise in procalcitonin and pentraxin 3. In only two of 22 patients, procalcitonin concentration rose above 2 ng mL(-1) during fever attack, compatible with the noninfectious nature of these attacks. Ferritin does not reach the high concentrations found in adult-onset Still's disease. Despite the defect in mevalonate kinase, a component of cholesterol metabolism, serum cholesterol did not change during attacks. IgD concentration is elevated regardless of disease activity, although there is appreciable variation during life. Its role in HIDS remains unclear.

CONCLUSION

The combination of high CRP concentration plus procalcitonin concentration <2 ng mL(-1) in a symptomatic HIDS patient might indicate a febrile attack without (bacterial) infection; this observation warrants further investigation for its usefulness as a marker in clinical practice.

Common mutations in the familial Mediterranean fever gene associate with rapid progression to disability in non-Ashkenazi Jewish multiple sclerosis patients

Ancient founder mutations in the Mediterranean fever gene, MEFV, are associated with familial Mediterranean fever, a recessive, episodic, inflammatory disease. Since these mutations are reported to express with above normal levels of acute phase reactants in healthy heterozygotes we postulated that the heterozygous phenotype could aggravate the clinical expression of ongoing autoimmune diseases. This study evaluated progression to disability in relapsing-remitting multiple sclerosis (RR-MS) patients of non-Ashkenazi and Ashkenazi origin carrying an MEFV mutation, particularly the detrimental M694V, using the expanded disability status scale (EDSS). In the non-Ashkenazi patients group (n=48), carriers (n=17) presented with a two-fold higher fraction which reached EDSS=3.0 and 6.0 compared to noncarriers (n=31) despite a comparable mean of MS duration. The median time to reach EDSS=3.0 was 2 years in the carriers vs 10 years in noncarriers (P=0.007); The median time to reach EDSS=6.0 was 6 years vs 23 years, respectively (P=0.003). M694V heterozygous patients reached both EDSS milestones earlier than other patients. Progression to disability was not enhanced in Ashkenazi RR-MS carriers (n=12, noncarriers n=59). In conclusion, non-Asheknazi MS patients carrying one mutated MEFV gene, particularly M694V, expressed rapid progression to disability. The expressed mutation may increase inflammatory damage inflicted by autoimmune responses.