Deep phenotyping of facioscapulohumeral muscular dystrophy type 2 by magnetic resonance imaging

BACKGROUND AND PURPOSE

The aim was to define the radiological picture of facioscapulohumeral muscular dystrophy 2 (FSHD2) in comparison with FSHD1 and to explore correlations between imaging and clinical/molecular data.

METHODS

Upper girdle and/or lower limb muscle magnetic resonance imaging scans of 34 molecularly confirmed FSHD2 patients from nine European neuromuscular centres were analysed. T1-weighted and short-tau inversion recovery (STIR) sequences were used to evaluate the global pattern and to assess the extent of fatty replacement and muscle oedema.

RESULTS

The most frequently affected muscles were obliquus and transversus abdominis, semimembranosus, soleus and gluteus minimus in the lower limbs; trapezius, serratus anterior, latissimus dorsi and pectoralis major in the upper girdle. Iliopsoas, popliteus, obturator internus and tibialis posterior in the lower limbs and subscapularis, spinati, sternocleidomastoid and levator scapulae in the upper girdle were the most spared. Asymmetry and STIR hyperintensities were consistent features. The pattern of muscle involvement was similar to that of FSHD1, and the combined involvement of trapezius, abdominal and hamstring muscles, together with complete sparing of iliopsoas and subscapularis, was detected in 91% of patients. Peculiar differences were identified in a rostro-caudal gradient, a predominant involvement of lower limb muscles compared to the upper girdle, and in the higher percentage of STIR hyperintensities in FSHD2.

CONCLUSION

This multicentre study defines the pattern of muscle involvement in FSHD2, providing useful information for diagnostics and clinical trial design. Both similarities and differences between FSHD1 and FSHD2 were detected, which is also relevant to better understand the pathogenic mechanisms underlying the FSHD-related disease spectrum.

Follicular occlusion tetrad in a male patient with pachyonychia congenita: clinical and genetic analysis

The case of a 24-year-old male patient affected by follicular occlusion tetrad (acne conglobata, hidradenitis suppurativa, pilonidal cyst and dissecting cellulitis of the scalp) associated with clinical signs of pachyonychia congenita (PC)-2 (focal palmoplantar keratoderma, plantar pain, onycodystrophy and multiple cysts) is reported. The diagnosis was supported by genetic analysis that showed heterozygous mutation within the exon 1 of KRT17 gene. This case may reflect different expressions of a phenotypic spectrum induced by a common genetic alteration.

Interobserver Reproducibility of Immunohistochemical Her-2/Neu Assessment in Human Breast Cancer: An Update from INQAT round III

The clinical interest in HER-2/neu is related to trastuzumab, a drug used to treat patients with invasive breast carcinoma overexpressing the HER-2/neu protein. It is very important to correctly identify those patients who may benefit from trastuzumab by accurate assessment of the HER-2/neu status. Of the various methods available, the Dako Herceptest for immunohistochemical assay is considered the most reliable to reach this goal. The aim of this study was to investigate within a group of Italian laboratories the reproducibility of the results of HER-2/neu assessment by means of the Dako scoring system on slides stained with the Herceptest kit. This study was also conceived as the continuation of one of our previous studies, which was similar in its aims but different in the classification criteria adopted. Our results show that, whereas the intra-observer reproducibility was generally satisfactory, the interobserver reproducibility was not. Moreover, our findings confirm that the two extreme classes (0 and 3+) are more easy to identify than the other two and that the Herceptest does not allow to discriminate optimally between scoring classes 2+ and 3+. These findings are relevant in clinical practice where the treatment choice is based on categories defined by this assay, suggesting the need of adopting educational programs and/or new reference materials to improve the assay performance.

PCR-based approach for qualitative molecular analysis of six neurotropic pathogens

In the last few years, polymerase chain reaction analysis is frequently required to improve the detection of pathogen infections in central nervous system as a potential cause of neurological disorders and neuropsychiatric symptoms. The goal of this paper is to set up a fast, cheap and reliable molecular approach for qualitative detection of six neurotropic pathogens. A method based on PCR has been designed and implemented to guarantee the qualitative DNA detection of herpes simplex virus types 1 and 2 (HSVI/II), Epstein-Barr virus (EBV), cytomegalovirus (CMV), varicella-zoster virus (VZV), rubella virus (RUBV) and Toxoplasma gondii in the cerebrospinal fluid, where otherwise they are barely detectable. Each PCR assay was tested using dilutions of positive controls, which demonstrated a sensitivity allowing to detect up to 102 copies/ml in PCR and 10 copies/ml in real-time PCR for each pathogen. Once been set up, the protocol was applied to evaluate the cerebrospinal fluid from 100 patients with suspected infectious diseases of the central nervous system and 50 patients without any infection. The method allowed to identify 17 positive cerebrospinal fluid with polymerase chain reaction and 22 with real-time PCR (RT-PCR), respectively. Therefore, application of RT PCR allows a fast and sensitive evaluation of neurotropic DNA pathogens in the course of diagnostic routine within neurological units.

Assessing individual risk for AMD with genetic counseling, family history, and genetic testing

PurposeThe goal was to develop a simple model for predicting the individual risk profile for age-related macular degeneration (AMD) on the basis of genetic information, disease family history, and smoking habits.Patients and methodsThe study enrolled 151 AMD patients following specific clinical and environmental inclusion criteria: age >55 years, positive family history for AMD, presence of at least one first-degree relative affected by AMD, and smoking habits. All of the samples were genotyped for rs1061170 (CFH) and rs10490924 (ARMS2) with a TaqMan assay, using a 7500 Fast Real Time PCR device. Statistical analysis was subsequently employed to calculate the real individual risk (OR) based on the genetic data (ORgn), family history (ORf), and smoking habits (ORsm).Results and conclusionThe combination of ORgn, ORf, and ORsm allowed the calculation of the Ort that represented the realistic individual risk for developing AMD. In this report, we present a computational model for the estimation of the individual risk for AMD. Moreover, we show that the average distribution of risk alleles in the general population and the knowledge of parents' genotype can be decisive to assess the real disease risk. In this contest, genetic counseling is crucial to provide the patients with an understanding of their individual risk and the availability for preventive actions.

Sentinel node mapping with radiotracer alone in vulvar cancer: a five year single-centre experience and literature review

PURPOSE OF INVESTIGATION

The pathologic status of lymph node represents the most important prognostic factor in vulvar cancer patients, but a complete groin dissection is associated with high post-operative morbidity. Sentinel lymph node (SLN) could be representative of the totality of regional lymph nodes and consequently its biopsy might have a significant impact on clinical management in vulvar cancer patients.

MATERIALS AND METHODS

From January 2006 to December 2010 45 patients with vulvar carcinoma are evaluated. Preoperative lymphatic mapping with technetium-99m-labeled nanocolloid was performed in all patients, followed by radioguided intraoperative detection. The detection rate is 100% of patients. All the SLNs were dissected separately for histopathological evaluation and a routine inguinofemoral lymphadenectomy was performed.

RESULTS

Nine patients had positive SLNs. In the remaining 36 patients with negative SLNs, one of them showed positive non-SLNs at histological examination. It was the only false negative case in the present series.

CONCLUSIONS

Based on literature review, lymphoscintigraphy and sentinel node biopsy under gamma-detecting probe guidance offer a reliable and careful method to identify sentinel node in early vulvar cancer. Taking certain guidelines, SLN biopsy seems to be a safe alternative to inguinofemoral node dissection in order to reduce morbidity of surgical treatment.

Association of KIF3A, but not OVOL1 and ACTL9, with atopic eczema in Italian patients

BACKGROUND

Atopic eczema (AE) (OMIM %603165) is the most common chronic inflammatory skin disease characterized by xerosis, pruritus, and erythematous lesions with increased transepidermal water loss. It's a complex disease due to the interaction between environmental and genetics factors. To date, different loci have been related to the disease.

OBJECTIVES

To verify the association, between AE and rs479844, rs2164983, and rs2897442, target for OVOLI (11q13), ACTL9 (19p13.2), and in KIF3A (5q31) genes in the Italian population. Recently, these SNPs have been validated as associated to the disease.

METHODS

A case-control study testing a cohort of 359 AE cases and 778 controls.

RESULTS

We confirmed the association between rs2897442 in KIF3A gene and the disease at both allele and genotype level (P-value: 4.8 × 10(-4) and P-value: 6.3 × 10(-4), respectively). The C allele of the SNP showed an Odds Ratio (OR) of 1.46 (95% CI 1.18-1.82), moreover the CC genotype achieved an OR of 2.77 (95% CI 1.66-4.61). We failed to reveal association between AE and the other two SNPs tested.

CONCLUSIONS

Our study indicated KIF3A as a novel gene implicated in the development of AE in the Italian population.

Allele frequencies of the new European Standard Set (ESS) loci in a population of Apulia (Southern Italy)

Allele frequencies of five miniSTRs loci (D1S1656, D2S441, D12S391, D10S1248 and D22S1045) included in the new European Standard Set (ESS) were calculated from a sample of 150 unrelated individuals from Apulia, a Region of Southern Italy. Two different PCR Amplification Kits were used, in order to evaluate the concordance of the genotypes. The results obtained with the two kits showed no differences in all genotype profiles. No deviation from Hardy-Weinberg expectations was detected at either locus. Moreover genetic analysis using Fst estimation showed no evidence for differentiation at the five new loci between Apulia and Italian populations. The high levels of polymorphisms of the analyzed markers in the Apulian population allow to confirm that these markers are useful tools in paternity and forensic analysis from degraded DNA samples.

Effects of Paraquat and Capsaicin on the Expression of Genes Related to Inflammatory, Immune Responses and Cell Death in Immortalized Human HaCat Keratinocytes

The present experiments were aimed to characterize in immortalized human HaCat keratinocytes the gene expression induced by paraquat and capsaicin, two agents known to induce cell death or to affect inflammatory and pain pathways, respectively. In particular, the following set of genes were analysed by qRealtime PCR: CXCL10,CXCL11, IL-10 (inflammatory and immune responses), TP73, BCL2, (apoptotic and anti-apoptotic genes), MMP9 (proteolysis), SOD-1, BAK-1 and CAT (peroxysomal and microsomal oxidation pathways). In this way, we were able to differentiate the two toxins since they had a different profile of gene expression. In fact, paraquata was found to activate set of genes involved in inflammatory (CXL10,CXL11 and IL-10), and cell death (BCL2, BAK-1, MMP9) pathways. Another specific site of action of paraquat was represented by an activation of the gene involved in SOD-1 transcription. On the contrary, capsaicin was found to produce only an up-regulation of BCL2, an anti-apoptotic gene and MMP9, whereas no significant changes were reported in genes involved in inflammatory and immune responses. Finally, in comparison to previous experiments carried out with TNF-α and IL-1β, we have shown that paraquat produced a similar pattern of activation of set of genes involved both in inflammation and apoptosis.

Rescue of murine silica-induced lung injury and fibrosis by human embryonic stem cells

Alveolar type II pneumocytes (ATII cells) are considered putative alveolar stem cells. Since no treatment is available to repair damaged epithelium and prevent lung fibrosis, novel approaches to induce regeneration of injured alveolar epithelium are desired. The objective of this study was to assess both the capacity of human embryonic stem cells (HUES-3) to differentiate in vitro into ATII cells and the ability of committed HUES-3 cells (HUES-3-ATII cells) to recover in vivo a pulmonary fibrosis model obtained by silica-induced damage. In vitro differentiated HUES-3-ATII cells displayed an alveolar phenotype characterised by multi-lamellar body and tight junction formation, by the expression of specific markers such as surfactant protein (SP)-B, SP-C and zonula occludens (ZO)-1 and the activity of cystic fibrosis transmembrane conductance regulator-mediated chloride ion transport. After transplantation of HUES-3-ATII cells into silica-damaged mice, histological and biomolecular analyses revealed a significant reduction of inflammation and fibrosis markers along with lung function improvement, weight recovery and increased survival. The persistence of human SP-C, human nuclear antigen and human DNA in the engrafted lungs indicates that differentiated cells remained engrafted up to 10 weeks. In conclusion, cell therapy using HUES-3 cells may be considered a promising approach to lung injury repair.

Effects of TNF-α and IL-1β on the Activation of Genes Related to Inflammatory, Immune Responses and Cell Death in Immortalized Human HaCat Keratinocytes

The present experiments were designed to characterize by microarray analysis the transcriptional responses of human keratinocytes (HaCat) to TNF-α and IL-1β, given alone or in combination, in order to better understand the mechanisms underlying inflammatory, immune responses and cell death in which both cytokines play a pathophysiological role. Significant differences in the percentage and quality of genes dysregulated by TNF-α and IL-1β were shown. Both cytokines activated a series of genes involved in inflammatory, immune response as well as in cell death. In our experimental conditions, TNF-α, in contrast to IL-1β, did not induce a significant level of apoptosis in keratinocytes. However, given together both cytokines produced a significant decrease in apoptotic cells and synergistic transcriptional response which was due to the activation of several specific genes occurring after application of each cytokine. TNF-α and IL-1β evoked apoptotic effect and transcriptional responses were linked to the stimulation of their specific receptors since a pre-treatment with monoclonal antibodies vs TNF-α and/or IL-1β receptors was able to significantly reduce them.

"The Linosa Study": epidemiological and heritability data of the metabolic syndrome in a Caucasian genetic isolate

BACKGROUND AND AIMS

Growing evidence suggests that the metabolic syndrome (MetS) has both a genetic and environmental basis. To evaluate the possibility of a further genetic analysis, we estimated prevalence rates and heritabilities for the MetS and its individual traits in the adult population of Linosa, a small and isolated Italian Island in the southern-central part of the Mediterranean Sea.

METHODS AND RESULTS

The Linosa Study (LiS) group consisted of 293 Caucasian native subjects from 51 families (123 parents; 170 offsprings). The MetS was defined according to NCEP/ATP III criteria and the following prevalence rates were calculated: hyperglycaemia 20.3%; central obesity 34.9%; hypertension 43.4%; hypertriglyceridaemia 29.9%; "low HDL" 56.6%; MetS 29.9%. Waist circumference was significantly related to all the quantitative parameters included in the NCEP/ATP III MetS definition. The MetS showed a heritability of 27% (p=0.0012) and among its individual components, treated as continuous and discrete traits, heritability ranged from 10% for blood glucose to 54% for HDL-cholesterol. Among MetS subtypes, the clustering of central obesity, hypertriglyceridaemia and "Iow HDL" had the highest heritability (31%; p<0.001).

CONCLUSION

These data showed high prevalence rates for the MetS and its related traits in an isolated and small Caucasian population. The appreciable heritability estimates for the MetS and some of its components/clusters in the LiS population might support the observation of genetic factors underlying the pathogenesis of the MetS and encourage further analysis to identify new susceptibility genes.

Divergent phenotype of two siblings human leukocyte antigen identical, affected by nonclassical and classical congenital adrenal hyperplasia caused by 21-hydroxylase deficiency

CONTEXT

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders most often caused by enzyme 21-hydroxylase deficiency. Most mutations causing enzymatic deficiency are generated by recombinations between the active gene CYP21 and the pseudogene CYP21P. Only 1-2% of affected alleles result from spontaneous mutations. The phenotype of CAH varies greatly, usually classified as classical or nonclassical, depending on variable degree in 21-hydroxylase activity. Here we report a divergent phenotype of two human leukocyte antigen identical siblings, affected by nonclassical and classical CAH caused by 21-hydroxylase deficiency due to different genotype.

PATIENTS AND METHODS

Using direct sequencing method and Southern blot, we studied two children (one male and one female), affected, respectively, by nonclassical and classical CAH and their parents.

RESULTS

The mother was heterozygous for the Q318X mutation, and the father was heterozygous for the V281L mutation. The brother was a compound heterozygote for the mutations V281L and Q318X, whereas the proband was compound heterozygote for the Q318X mutation and a large conversion. The two children are human leukocyte antigen identical (A*02;B*14;DRB1*01/A*33;B*14;DRB1*03).

CONCLUSIONS

Different phenotype of the proband is the result of compound heterozygosity for the maternal mutation Q318X and a de novo large conversion.

Transmission ratio distortion in the spinal muscular atrophy locus: Data from 314 prenatal tests

BACKGROUND

Spinal muscular atrophy (SMA) is a recessive neurodegenerative disorder characterized by the loss of alpha-motor neurons in the spinal cord and subsequent death of motor neuron cells. SMA occurs with a frequency of 1 in 6,000 live births, with a carrier frequency of 1 in 40, and is a leading genetic cause of infant mortality. SMA is caused by loss or mutation of the telomeric survival motor neuron gene (SMN1), which is deleted in almost 94% of SMA patients

OBJECTIVE

To analyze the transmission ratio at the SMA locus, examining the segregation of the SMN1-deleted alleles in 314 fetuses from carrier parents who requested prenatal testing for the disease.

METHODS

Prenatal diagnosis of SMA in families at 25% risk of the disease has been performed on chorionic villous sampling specimens, through direct detection of the SMN1 gene mutation and linkage analysis using microsatellite markers from the 5q13 region. Analysis of the genotypic/allelic frequencies of the SMN1 gene was performed using the chi2 test, assuming a recessive mendelian inheritance.

RESULTS

Of 314 fetuses analyzed, 95 were homozygous for the wild-type allele (30.3%), 154 were carriers (49.0%), and the remaining 65 were homozygous for the mutated allele (20.7%). Statistical analysis demonstrated that proportion of fetuses predicted with SMA is lower than 25% expected for a recessive disorder, resulting in a transmission rate of the SMN1-deleted allele deviant from the 50% expected in a random the segregation of a mendelian tract (p = 0.016)

CONCLUSIONS

This is the first study to evaluate the genotypic frequencies at the spinal muscular atrophy (SMA) locus based on data derived from prenatal analysis, which are not subject to ascertainment bias. The analysis showed a transmission ratio distortion at the SMA locus in favor of the SMN1 wild-type alleles.

Characterization of the loricrin (LOR) gene as a positional candidate for the PSORS4 psoriasis susceptibility locus

Psoriasis is a chronic inflammatory disease of the skin with both genetic and environmental risk factors. Non-parametric linkage analyses have mapped many susceptibility loci on different chromosomes. We mapped one of these loci, PSORS4, on human chromosome 1q21. Using the linkage disequilibrium approach, we refined the critical region to a specific genomic interval of about 100 Kb which contains only the loricrin (LOR) gene. Here we report a genetic and functional study of this gene to verify its involvement in psoriasis pathogenesis. We document low expression of LOR in psoriatic skin of patients selected from families in which the disease was segregating with the PSORS4 locus. Re-sequencing of the entire gene in a subset of patients revealed the existence of novel polymorphisms able to influence the protein structure, as shown by molecular modelling studies. However, no evidence for genetic association was detected in a large cohort of Italian nuclear families. This rules out the LOR gene as a candidate for the PSORS4 locus.

The level of soluble Granzyme A is elevated in the plasma and in the Vgamma9/Vdelta2 T cell culture supernatants of patients with active Behçet's disease

OBJECTIVE

Gramzyme A (GrA) is a serine proteinase with trypsin-like activity that is released extracellularly during the degranulation of cytotoxic cells. Among the cytotoxic cells, gamma/delta T cells participate in the early phases of the immune response and are known to express perforin and granzymes constitutively in agreement with their cytolytic pontential.

METHODS

GrA activity was detected using the synthetic substrate N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester in the plasma and supernatants of peripheral blood mononuclear cell cultured in the presence of Dimethylallyl pyrophosphate to obtain Vgamma9/Vdelta2 T cell expansion.

RESULTS

Significantly high levels of GrA were found in the serum and supernatants of lymphocytes from patients with active Behçet's disease cultured in the presence of DMAPP. Levels were found to be significantly lower after remission. A positive correlation was observed between GrA levels in the supernatants and the Vgamma9/Vdelta2 T cell expansion factor.

CONCLUSION

These results strongly suggest that Vgamma9/Vdelta2 T cells are active participants in the pathogenesis of the disease through their degranulation and granzyme release.

Impaired expression of erythrocyte glycosyl-phosphatidylinositol-anchored membrane CD59 in patients with psoriatic arthritis. Relation to terminal complement pathway activation

OBJECTIVE

Complement-mediated injury is regulated by many factors; among these CD59 has been identified as a widely distributed glycoprotein that inhibits membrane C5b-9 (terminal complement component) formation. The aim of the study was to assess erythrocyte CD59 expression in patients with psoriatic arthritis in order to understand the role of CD59 in the pathogenesis.

METHODS

Washed erythrocytes from 50 patients with psoriatic arthritis, 8 with cutaneous psoriasis and 24 healthy subjects were incubated with monoclonal anti-CD59 antibody followed by a second FITC conjugated antibody and fluorescence intensity analysed by FAC-Scan flow cytometer to assess their CD59 membrane expression. SC5b-9 levels were measured in the plasma by ELISA and results compared with CD59 values. Immune complexes, complement C3 and C4 and rheumatoid factor were also determined.

RESULTS

Impaired expression of erythrocyte membrane-anchored CD59 was found in patients with psoriatic arthritis; the lowest levels were seen in active patients (p < 0.01). Increased SC5b-9 was seen in the plasma of patients with active disease. An inverse correlation was also found between plasma C5b-9 and the CD59 expression levels (r = -0.81, p < 0.001).

CONCLUSION

The low CD59 expression on erythrocytes from patients with psoriatic arthritis may be an index of a low tissue CD59 expression. This impairment could facilitate the activation of complement pathway and increase the risk for arthritis. Membrane attack complex formation in deficient membrane bound CD59 may also exacerbate synovial cell injury and inflammation.

Humoral and cell mediated immune response to cow's milk proteins in Behçet's disease

OBJECTIVE

To investigate the humoral and cellular immune response against cow's milk proteins in Behçet's disease and to distinguish any behaviour during active or inactive disease.

METHODS

Peripheral blood mononuclear cells from 16 patients and from eight normal controls were cultured in the presence of phytohaemagglutinin (PHA), beta-casein, beta-lactoglobulin, or chicken egg albumin. Interferon gamma (IFNgamma) and interleukin 4 (IL4) were measured in the culture supernatants by enzyme linked immunosorbent assay (ELISA). Serum samples from 46 patients with Behçet's disease and from 37 healthy subjects were also studied for antibody detection. Antibodies to beta-casein, beta-lactoglobulin, and chicken egg albumin were determined by ELISA.

RESULTS

High IFNgamma but not IL4 levels were found in the supernatants of lymphocytes from patients with active disease cultured in the presence of cow's milk proteins. Levels were comparable with those obtained in cultures stimulated with PHA. A significantly higher level of anti-beta-casein and anti-beta-lactoglobulin IgG and IgA antibodies was found in patients with active Behçet's disease. No relation was found between their occurrence and the age of the patients, the duration of disease, or the presence of gastrointestinal abnormalities. Antibodies to chicken albumin were detected at low levels and with a prevalence similar to that of healthy subjects.

CONCLUSION

The results indicate that an active immune response occurs in Behçet's disease. This response involves an increased frequency of antibodies to cow's milk protein and a strong Th1 polarisation after exposure to these antigens. The occurrence of these abnormalities supports a putative role for cow's milk proteins immune response in the pathogenesis of Behçet's disease.

Mapping a dominant form of multinodular goiter to chromosome Xp22

Multinodular goiter (MNG) is a common disorder characterized by a nodular enlargement of the thyroid gland and occurring with a female&rcolon;male ratio of 5&rcolon;1. This article reports the analysis of an Italian three-generation pedigree MNG, including 10 affected females and 2 affected males. After linkage to candidate regions previously implicated in various forms of goiter was excluded, a novel MNG locus was searched. Because no male-to-male transmission was present in the study pedigree, an X-linked autosomal dominant pattern of inheritance was hypothesized. Therefore, 18 markers spaced at 10-cM intervals on the X chromosome were examined. A significant LOD score was observed in the Xp22 region, where marker DXS1226 generated a maximum LOD score of 4.73 at a recombination fraction of 0. Analysis of six flanking microsatellites confirmed these data, and haplotype inspection delimited a 9.6-cM interval lying between DXS1052 and DXS8039.

Glucose-induced loss of glycosyl-phosphatidylinositol-anchored membrane regulators of complement activation (CD59, CD55) by in vitro cultured human umbilical vein endothelial cells

AIMS/HYPOTHESIS

This study examines whether increased glucose concentrations are responsible for a decreased expression of membrane regulators of complement activation molecules. The effect of high glucose in determining an increase in membrane attack complex deposition on endothelial cells was also investigated.

METHODS

Endothelial cells were isolated from umbilical cord tissue, cultured in the presence of increased concentrations of glucose, and the expression of CD46, CD55, and CD59 was detected by ELISA (enzyme-linked immunosorbent assay) and by flow cytometry. Glucose-treated endothelial cells were also incubated with antiendothelial cell antibodies and fresh complement to assess the amount of membrane attack complex formation.

RESULTS

High concentrations of glucose decreased the expression of CD59 and CD55 by endothelial cells in a time-dependent and glucose concentration-dependent manner without affecting CD46 expression. High concentrations of soluble CD59 were found in the supernatants of cells treated with high glucose. The decrease in CD59 expression induced by high glucose concentrations was reversed by coincubation of cells with a calcium channel blocking agent (Verapamil). All of these effects were not reproduced by osmotic control media. Cells treated with concentrations of high glucose were more susceptible to complement activation and membrane attack complex formation after exposure to antiendothelial cell antibodies.

CONCLUSION/INTERPRETATION

We speculate that hyperglycaemia could directly contribute to a loss of CD59 and CD55 molecules through a calcium-dependent phosphoinositol-specific phospholipase C activation and subsequent regulation of cell wall expression of GPI-anchored proteins. This phenomenon could facilitate the activation of a complement pathway and could play a part in the aetiology of endothelial dysfunction in diabetes.

Polymorphonuclear leukocyte myeloperoxidase levels in patients with Behçet's disease

Myeloperoxidase was measured in the plasma and in the supernatants of polymorphonuclear granulocyte cultures from patients with Behçet's disease. High levels were found in both plasma and supernatants from patients with active disease. The addition of pentoxifylline to granulocyte cultures determined a significant decrease of myeloperoxidase levels in active patients only. Hyperactive neutrophils are present during the course of Behçet's disease and may be considered of importance in the pathogenesis of the vascular lesions.

Enhancement of endothelial cell E-selectin expression by sera from patients with active Behçet's disease: moderate correlation with anti-endothelial cell antibodies and serum myeloperoxidase levels

We studied the in vitro E-selection expression of endothelial cells treated with sera from patients with Behçet's disease (BD) and factors (anti-endothelial cell antibodies, anti-neutrophil cytoplasmic antibodies, cytokines, and myeloperoxidase (MPO) that may contribute to adhesion molecule expression. A total of 21 patients with BD and 27 healthy controls were studied. In vitro E-selectin endothelial cell expression was investigated by ELISA after HUVEC incubation with sera or purified IgG from patients with BD and controls. Increased E-selectin expression was observed when endothelial cells were incubated with sera from patients with active disease or from patients with circulating anti-endothelial cell antibodies and high levels of plasma myeloperoxidase. Abnormalities of endothelial cell function have been suggested to play a role in the occurrence of vascular damage in BD. Our findings suggest that anti-endothelial cell antibodies and neutrophil hyperactivity, as inferred from the high plasma MPO levels in patients with active disease, may explain endothelial cell activation and neutrophil accumulation in vascular lesions.

IgG anti-endothelial cell antibodies (AECA) in type I diabetes mellitus; induction of adhesion molecule expression in cultured endothelial cells

AECA were detected in 25 of 71 patients with type 1 diabetes mellitus and in two of 33 healthy subjects. Patients with diabetes of < 1 year duration and those with long-standing disease had the highest levels of these antibodies. Inhibition studies suggest that at least part of the AECA reactivity is due to cross-reactive anti-ssDNA antibodies. AECA-positive sera were able to increase intercellular adhesion molecule-1 (ICAM-1) and E-selectin on human umbilical vein endothelial cells (HUVEC). Increased binding of polymorphonuclear (PMN) cells was also found to accompany raised E-selectin expression. Soluble ICAM-1 and E-selectin were also found to be increased in the sera of AECA-positive patients. An effect of AECA on endothelial cell function is suggested in diabetes mellitus.

Anti-single-stranded DNA antibody in the sera of patients with type 2 diabetes mellitus. Relation to vascular complications

Anti-single-stranded(ss)DNA antibodies were searched for by enzyme-linked immunosorbent assay (ELISA) in the serum of 202 outpatients with non-insulin-dependent diabetes mellitus and 135 healthy subjects to investigate their prevalence in the serum of patients with type 2 diabetes and their relationship with the presence of vascular complications. Of the 202 patients 128 had vascular complications. Anti-ssDNA antibodies were observed to be significantly more frequent in the serum of patients with vascular complications (33.6%) and in particular in patients with overt nephropathy (50%) than in patients without complications (6.7%) or controls (6.7%). Anti-ssDNA antibodies have been previously described in patients with type 1 diabetes before clinical evidence of vascular disease and their cross-reactivity with a variety of anionic biological molecules or cells, i.e. platelets and endothelial cells, assessed. It seems not unreasonable that these auto-antibodies detected in patients with type 2 diabetes could be of importance in the pathogenesis or progression of angiopathy.

Detection of anti-myeloperoxidase antibodies in the serum of patients with type 1 diabetes mellitus

Anti-myeloperoxidase (anti-MPO) antibodies were detected in 34 of 88 (38%) patients with type 1 diabetes mellitus but in only 3 of 55 (5.7%) healthy subjects and in 4 of 20 patients with autoimmune disease. Specificity of anti-MPO antibodies was assessed by MPO inhibition studies. No relationship was found between the occurrence of anti-MPO and anti-thyroperoxidase antibodies. Levels of soluble intercellular adhesion molecule 1 (ICAM-1) were found to be higher in anti-MPO antibody-positive (n = 28, 508 +/- 126 ng/ml) than in anti-MPO antibody-negative (n = 58, 438 +/- 140 ng/ml: P < 0.05) patients. A state of chronic neutrophil activation has been described in diabetes mellitus. As anti-MPO antibodies can stimulate neutrophils to damage endothelial cells in systemic vasculitis, this suggests that a similar mechanism may be operative in the development of diabetic angiopathy.

Anti platelet property of anti-single-stranded DNA antibodies in type 1 (insulin-dependent) diabetes mellitus

Nineteen of 50 sera from children with type 1 (insulin-dependent) diabetes mellitus showed anti-platelet reactivity. This reactivity was significantly associated with the presence of proteoglycan cross-reactive anti-ssDNA antibodies. As well as DNA-anti-DNA interaction, increasing salt concentration of the dilution buffer caused a decrease in the binding of positive sera to platelets. Purified ssDNA inhibited also the anti-platelet reactivity of anti-ssDNA positive sera. The addition of purified IgG from anti-ssDNA positive but not from anti-ssDNA negative sera to washed platelets caused an increased collagen-induced platelet aggregation similar to that obtained with the addition of polycationic agents. It may be suggested that ionic interaction between anti-negative charged molecule antibodies (such as anti-ssDNA antibodies) and platelet surface negative charges may be a pathophysiological mechanism contributing to the altered platelet function observed in diabetes.

Inhibition of Fc gamma receptors in the plasma of subjects with Down's syndrome

Subjects with Down's syndrome have several immunological abnormalities. We examined the sera of 29 subjects with Down's syndrome for the presence of Fc gamma receptor blocking and for the presence of anti-ssDNA antibodies by EA rosette inhibition. Fifty-five percent of Down subjects had levels of inhibition above the upper limit of normality in comparison to 7% of normal controls. The finding that after polyethylene glycol precipitation of selected sera giving high levels of EA rosette inhibition there was a reduction or a disappearance of the EA rosette inhibition could indicate that the blocking factors detected behaved as immune complexes. Since almost all subjects with anti-ssDNA antibodies also had elevated values of EA rosette inhibition, a role for immune complexes eventually formed with autoantibodies in an Fc-mediated immunoregulatory system is suggested.

Two-site ELISA for quantification of the terminal C5b-9 complement complex in plasma. Use of monoclonal and polyclonal antibodies against a neoantigen of the complex

A quantitative ELISA procedure using monoclonal and polyclonal antibodies against neoantigens of the terminal C5b-9 complement complex has been developed. The ELISA was demonstrated to be both sensitive and reproducible. The normal range for C5b-9 determinations, defined as 2.5-97.5% interval of the values obtained in 76 healthy blood donors, was 3.12-10.3 AU/ml. The presence of rheumatoid factor did not affect the determination of C5b-9 as demonstrated by immunoabsorption studies.

Detection of the terminal fluid-phase complement complex, SC5b-9, in the plasma of patients with insulin-dependent (type I) diabetes mellitus. Relation to increased urinary albumin excretion and plasma von Willebrand factor

An ELISA was used to measure the fluid-phase complement complex in the plasma of 54 patients with insulin-dependent (type I) diabetes mellitus. Sixty-seven per cent of the diabetic patients had increased levels of SC5b-9. In individual diabetic patients, increased SC5b-9 was found to be significantly associated with the occurrence of anti-heparan sulphate cross-reactive anti-ssDNA antibodies and in some cases with circulating immune complexes. There was a significant correlation between levels of SC5b-9 and those of urinary albumin excretion rate (AER) (r = 0.39, P less than 0.01). Levels of AER were 8.4 +/- 2.26 micrograms/min and 2.04 +/- 0.35 micrograms/min in the SC5b-9 positive and negative patients, respectively (P less than 0.01). A relationship was also found between SC5b-9 and plasma von Willebrand Factor (r = 0.45, P less than 0.02), von Willebrand factor was 189.2 +/- 19.3% and 132.3 +/- 19.6% in SC5b-9 positive and negative patients, respectively (P less than 0.05). It may be that the abnormalities found in this study play a role in the pathogenesis of the late diabetic vascular complications.

Increased plasma levels of IgA-IgG immune complexes and anti-F(ab')2 antibodies in patients with type 2 (non insulin-dependent) diabetes mellitus and microangiopathy

C3 fixing IgA immune complexes were found to be elevated in 25% of patients with type 2 (non insulin-dependent) diabetes mellitus as compared to healthy subjects (2%). Immune complexes containing both IgA and IgG were found in 42% of the diabetic population but not in controls. The presence of C3-IgA and/or IgA/IgG immune complexes correlated with the occurrence of antiglobulins antibodies of IgA class in particular with autoantibodies reactive with the Fab2 portion of IgG. These immunopathological findings were more frequent in patients that exhibited microvascular complications and in particular in patients with proliferative retinopathy. These and our previous results strongly suggest a role of IgA system abnormality in the pathogenesis of diabetic vascular complications.

Cross-reactivity of anti-ssDNA antibodies with heparan sulfate in patients with type I diabetes mellitus

Anti-single-stranded-DNA antibodies cross-reactive with heparan sulfate were detected in serums of patients with type I (insulin-dependent) diabetes mellitus. The results suggested that heparan sulfate, the major glycosaminoglycan constituent of the glomerular basement membrane, may serve as a target antigen in vivo for cross-reactive anti-DNA antibodies. These polyreactive antibodies, directed toward repeating negatively charged units, may neutralize the heparan sulfate-associated polyanionic sites in the glomerulus, leading to an abnormal permeability of anionic plasma proteins.

Serum levels of type III procollagen peptide in diabetes mellitus

Serum levels of type III procollagen peptide (P-III-P) were investigated in 19 patients with type 1 (insulin-dependent) and in 48 (25 orally treated, 23 insulinized) patients with type 2 (non insulin-dependent) diabetes mellitus. Among patients with type 2 diabetes, 16 orally treated and 14 insulin-treated subjects had macrovascular complications. P-III-P levels were not correlated with the duration of diabetes and with glucose control, nor were there any significant sex and age differences in the levels. P-III-P values were significantly higher in the sera of insulin-treated non insulin-dependent diabetic patients with macroangiopathy. These high values (18.5 +/- 10.8 ng/ml) were in contrast with normal values in healthy subjects (8.5 +/- 2.5, P less than 0.001), insulin-dependent diabetics (9.9 +/- 3.4 ng/ml, P less than 0.01), non insulin-dependent diabetics treated with oral agents (8.2 +/- 2.6 ng/ml, P less than 0.001) and insulin-treated non insulin-dependent patients without macroangiopathy (8.2 +/- 4.9 ng/ml, P less than 0.001). Although this study does not demonstrate that an increase in type III collagen synthesis is responsible for the pathogenesis of macroangiopathy, it suggests that insulin-dependent fibroblast sensitization may play a role in the acceleration and progression of macroangiopathy.

[Velocity of nerve conduction in children and adolescents with type I diabetes mellitus: clinical, metabolic and immunologic correlations]

Clinical, metabolic, neurophysiologic and immunological data were obtained in a group of 50 patients with type I diabetes mellitus Results were compared with those obtained in 30 healthy subjects of comparable age. M.N.C. (median nerve conduction) velocities and sensitive latency were observed to be significant lower in the diabetic patients rather than in the controls. These abnormalities were correlated with the duration of diabetes rather than with the glucose control. The positivity for circulating immune complexes was found to be associated with a significant reduction of median sensory nerve conduction velocity. There results suggest that in addition to metabolic, genetic, vascular and hormonal abnormalities also immunologic factors may play a role in the pathogenesis of diabetic neuropathy.

The relationship of insulin antibodies, platelet-fixing immune complexes and platelet-associated IgG to in vitro platelet aggregation and thromboxane B2 synthesis in childhood type 1 (insulin-dependent) diabetes mellitus

The relationship of insulin antibodies, platelet-fixing soluble immune complexes and platelet associated IgG to in vitro platelet aggregation and thromboxane B2 synthesis was studied in a group of children with type 1 (insulin-dependent) diabetes mellitus. Insulin antibodies, through the formation of insulin anti-insulin platelet-fixing immune complexes, seem to increase the levels of platelet associated IgG and both insulin immunity and increased platelet associated IgG are associated with the highest degree of platelet aggregation and thromboxane synthesis. These data suggest a possible role of immune factors in the platelet disfunction of diabetic subjects. Both platelet abnormalities and immune factors have been thought to play a role in the pathogenesis of the late diabetic complications. In this paper data concerning a possible interaction between these two factors are presented.

Collagen binding activity in sera of patients with insulin-dependent (type 1) and non insulin-dependent (type 2) diabetes mellitus

An increase in the capacity of serum IgG to bind to native type IV collagen was observed in patients with both insulin-dependent and non insulin-dependent diabetes mellitus. This increased binding seems to be due to circulating immune complexes in the majority of the cases and to autoantibodies in some. The increased collagen binding activity was associated in postpubertal patients with the presence of diabetic microangiopathy, suggesting a pathogenetic role.

Autoantibodies to albumin in the plasma of patients with diabetes mellitus. Relationship with circulating immune complexes

Anti-albumin antibodies that recognize glutaraldehyde treated albumin have been detected in diabetes mellitus, belonging to all immunoglobulin classes. Anti-albumin antibodies have been found to be closely associated with circulating immune complexes, suggesting a role in their formation. It is suggested that such immune complexes may account for the positive immunofluorescence findings of albumin, immunoglobulin and complement in blood vessels previously reported in diabetes mellitus.

Circulating immune complexes and platelet thromboxane synthesis in patients with insulin-dependent (type I) diabetes mellitus

Platelets from diabetic subjects with circulating immune complexes (CIC) synthesized greater amounts of thromboxane than did platelets from CIC-negative patients or controls. In view of the known action of CIC on platelet function, a relationship between these two factors may be suggested in the initiation and progression of microangiopathy in diabetes.

Contribution of secretory IgA, polymeric IgA and IgA/secretory component-containing circulating immune complexes to the serum hyper-IgA in diabetes mellitus

The relative contribution of secretory IgA, monomeric and polymeric IgA and IgA/secretory component-containing immune complexes was investigated in sera of diabetic patients. Secretory IgA and immune complexes containing IgA and secretory component seem to participate in the hyper-IgA of patients with Type 2 (non-insulin-dependent) diabetes only, suggesting an altered hepatic clearance via secretory component receptors on hepatocytes. In Type 1 (insulin-dependent) diabetes, the high serum IgA levels might be explained by an increase in IgA production in response to antigenic stimuli. Evidence is also accumulated that immune complexes containing IgA of mucosal origin may be involved in microangiopathy production in Type 2 diabetes.

Serum hyper IgA in diabetes mellitus: I. Increase in the proportion of the polymeric to the monomeric form

The relative contribution of monomeric and polymeric IgA was investigated in diabetic sera showing that 80-87% of IgA in diabetes are polymeric. A defective mechanism of hepatobiliary transport of IgA is suggested in diabetes mellitus.