SAT0527 COMBINED EFFECT OF COMMON VARIANTS IN EXON 2 OR EXON 3 AND A PATHOGENIC MUTATION IN EXON 10 OF THE MEDITERRANEAN FEVER GENE ON INFLAMMASOME ACTIVATION IN JAPANESE PATIENTS WITH FAMILIAL MEDITERRANEAN FEVER

Background:

Familial Mediterranean fever (FMF) is an autoinflammatory disease that is caused by Mediterranean fever (MEFV) gene mutations. It is characterized by recurrent and self-limiting febrile attacks within a short period. Although the pathologic significance ofMEFVexon 2 or exon 3 common variants in patients with FMF is modest and these variants are usually associated with less severe clinical presentations of FMF (1, 2), their combined effects with pathogenic mutation in exon 10 remain to be evaluated.

Objectives:

To determine the combined effect of common variants on clinical manifestations and inflammasome activity, we compared the clinical and laboratory characteristics between the coexistence and non-coexistence ofMEFVexon 2 or exon 3 variants in patients with FMF that had a heterozygousMEFVexon 10 mutation.

Methods:

We excluded patients with FMF that had twoMEFVexon 10 mutations in one or more alleles and those withMEFVvariants in exons other than in exons 2, 3, or 10. Finally, we reviewed 131 Japanese patients with FMF that had a heterozygousMEFVexon 10 mutation, and they were divided into the groups with and withoutMEFVexon 2 or exon 3 variants of 34 and 97, respectively. All enrolled patients had only a heterozygous M694I mutation in exon 10 of theMEFVgene. We measured serum IL-18 levels at remission without febrile attacks in the groups with and withoutMEFVexon 2 or exon 3 variants of 9 and 31, respectively.

Results:

In the univariate analysis, the group with variants in exon 2 or exon 3 had significantly earlier onset (16.0 years v.s. 20.5 years, p = 0.04), a higher percentage of thoracic pain with febrile attacks (68% v.s. 44%, p = 0.02), a higher frequency of attack (1.0/month v.s. 0.5/month, p = 0.02), and a higher IL-18 level in the serum at remission (606.3 pg/ml v.s. 168.4 pg/ml, p = 0.04, Figure 1) compared to the group without these variants. Importantly, multivariate analyses showed that the coexistence ofMEFVexon 2 or exon 3 variants and an exon 10 mutation was independently and significantly associated with earlier onset of FMF (p = 0.049) and thoracic pain (p = 0.03).

Figure 1.

Conclusion:

Our results suggest that the coexistence ofMEFVexon 2 or exon 3 variants and aMEFVexon 10 mutation has combined effects on inflammasome activation in the Japanese population.

References:

[1]Migita K, Uehara R, Nakamura Y, et al. Familial Mediterranean fever in Japan. Medicine (Baltimore). 2012 Nov;91(6):337-43.

[2]Shinar Y, Livneh A, Langevitz P, Genotype-phenotype assessment of common genotypes among patients with familial Mediterranean fever. J Rheumatol. 2000;27(7):1703.

Disclosure of Interests:

None declared

AB0988 CLINICAL FEATURES AND ANALYSIS OF MEFV GENE IN 31 PATIENTS WITH FAMILIAL MEDITERRANEAN FEVER (FMF)

Background:

FMF is recessive systemic autoinflammatory disorder characterized by recurrent fever, peritonitis, pleuritis, pericarditis and arthritis accompanied with headache and abdominal pain. Mutation of MEFV gene encoding pyrin resulted in inflammasome activation and the uncontrolled production of IL-1β. Overview of pathogenesis, clinical features and management in Japanese patients with FMF had been reported. However, the differences of clinical features between mutated and non-mutated of MEFV still remain unclear.

Objectives:

We have analyzed 31 Japanese patients with FMF in Gifu district to clarify the association between various clinical features and mutation ofMEFV.

Methods:

Genomic DNA were purified from white blood cells in 31 FMF patients, and mutated MEFV has been explored. We have analyzedMEFV, TNFRSF1A, MVK and NLRP3 genesin 31 patients with FMF except for 1 patient. Therefore, we excluded another autoinflammatory diseases such as TNF receptor-associated syndrome (TRAPS), mevalonate kinase deficiency and cryopyrin-associated periodic syndrome. Clinical symptoms and laboratory data were analyzed around onset time. Each patient had been treated with colchicine (0.5-2 mg).

Results:

Characteristics of Patients with FMF (22 female/9 male) were as follows; Onset time were 0-56 years-old (21.4 ±11.8), and Frequencies of clinical symptoms such as periodic fever, headache, abdominal pain, arthralgia, chest pain, cervical lymph nodes swelling, and myalgia were 31/31, 9/31, 8/31, 6/31, 5/31, 3/31 and 1/31, respectively (double symptoms were observed). Patients with FMF were divided into 3 groups as follows; Patients with typical compound heterozygous mutations of MEFV (E148Q /M694I) which indicated exon 10 mutation, were 5 cases (G1). Patients with atypical mutations, except for exon 10, such as 133G>A in 3UTR, exon 1 (E84K), 2 (L110P, E148Q), 3(R202Q, P257L, G304R, P369S, R408Q), 5(S503C) and 9(I591M) were 13 cases (G2). Patients with no mutations in MEFV gene were 12 cases (G3). There were no significant differences of age at first visiting hospital (FV)and onset age of fever attack (O) (FV: 29.0 ± 15.6, 27.1 ± 12.5 years-old (yo) and 34.7 ± 12.7 yo, O: 21.0 ± 17.6 yo, 17.8 ± 12.1 yo and 25.2 ± 6.5). But significant differences in duration of fever attack (D) and frequency of fever attack (FF) between G1 and G2 or G3 were observed as follows; (D: 2.2 ± 0.4 days vs 5.5 ± 3.1 days, P<0.05, and 3.8 ± 1.7 days), FF: 0.72 ± 0.3/month (M), 1.24 ± 1.1/M, and 1.5 ± 0.7/M vs group1, P<0.05), respectively. Laboratory examinations such as WBC, CRP and serum amyloid A (SAA)at fever attack were not significantly different between 3 groups. All of those patients were effective for colchicine treatment except for 2 patients in group 1 because of loss of hair, severe diarrhea and liver dysfunction due to side effects of colchicine. Finally, 4 patients in G1and G2 received canakinumab treatment. Patients withMEFVmutations have no family histories. Mutations of E148Q were found in 12 patients (40%).

Conclusion:

We have examined association between clinical features and mutations of MEFV in 31 patients in Gifu district, suggesting that duration of fever attacks and frequency of fever attacks in G1 are significantly shorter than G2 and G3, respectively in Japanese patients with FMF. Mutations of E148Q in exon 2 were observed in 16-23 % of normal Japanese patients, indicating that E148Q is the polymorphism or accelerating factor.

Disclosure of Interests:

None declared

Characteristic elevation of soluble TNF receptor II : I ratio in macrophage activation syndrome with systemic juvenile idiopathic arthritis

To investigate the clinical significance of soluble tumour necrosis factor receptor (sTNF-R) II/I ratio as an indicator of the diagnosis of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (s-JIA), we measured the serum sTNF-RI and II levels in 117 patients with s-JIA, including 29 patients with MAS, 15 with Epstein-Barr virus-induced haemophagocytic lymphohistiocytosis (EBV-HLH), 15 with Kawasaki disease (KD) and 28 healthy controls (HCs). We determined their correlation with measurements of disease activity and severity. Furthermore, we measured serum interleukin (IL)-18 levels in patients with EBV-HLH and compared these in levels in patients with MAS. The sTNF-RII/I ratio was elevated significantly in MAS and EBV-HLH patients compared with those in the acute phase of s-JIA and KD patients, whereas there were no significant differences between HCs and those in the acute phase of s-JIA. The sTNF-RII/I ratio increased profoundly as MAS developed and correlated positively with disease activity. Serum IL-18 levels were elevated significantly in MAS patients compared with EBV-HLH patients. The monitoring of serum IL-18 and sTNF-RII/I might be useful for the diagnosis of MAS and the differentiation between MAS and EBV-HLH.

Development of IgA nephropathy-like glomerulonephritis associated with Wiskott-Aldrich syndrome protein deficiency

Wiskott-Aldrich syndrome (WAS) is a rare X-linked disorder caused by mutations in the WAS gene. Glomerulonephritis is a frequent complication, however, histopathological data from affected patients is scarce because the thrombocytopenia that affects most patients is a contraindication to renal biopsies. We found that WASp-deficient mice develop proliferative glomerulonephritis reminiscent of human IgA nephropathy (IgAN). We examined whether increased aberrant IgA production is associated with the development of glomerulonephritis in WASp-deficient mice. Serum IgA and IgA production by splenic B cells was increased in WASp-deficient mice compared to wild-type (WT) mice. A lectin-binding study revealed a reduced ratio of sialylated and galactosylated IgA in the sera from old WASp-deficient mice. Circulating IgA-containing immune complexes showed significantly higher titers in WASp-deficient mice compared to WT mice. These results indicate that the increased IgA production and aberrant glycosylation of IgA may be critically involved in the pathogenesis of glomerulonephritis in WAS.

Molecular and immunohistochemical detection of rotavirus in urinary sediment cells of children with rotavirus gastroenteritis

This is the first report showing that rotavirus infects the urinary sediment cells in immunocompetent children with rotavirus gastroenteritis. We found that inclusion-bearing cells were frequently detected in the urine samples of patients with rotavirus gastroenteritis. These cells were positive for cytokeratin, which was sometimes coexpressed with rotavirus antigen, in our immunohistochemical analysis. Moreover, in nested RT-PCR experiments, we detected rotavirus double-stranded RNA in some urine samples of patients with rotavirus gastroenteritis. We concluded that rotavirus could lead to infection of the urinary sediment cells concomitantly with rotavirus gastroenteritis.

Promoter DNA methylation of CD10 in infant acute lymphoblastic leukemia with MLL/AF4 fusion gene

10045

Background: Infant ALL displays distinct biologic and clinical features with a poor prognosis. The CD10-negative immunophenotype of infant ALL is a hallmark and provides a predictable signature of MLL rearrangements. While CD10 negativity reflects an earlier stage of B-cell development, complete IgH gene rearrangements (VDJH) show more mature IgH status. Discordance between immunophenotype and genotype of infant ALL suggests an aberrant process in immunophenotypic steps of differentiation or a secondary down-regulation of CD 10 expression associated with MLL rearrangements. We performed methylation analysis of full promoter regions of the CD10 gene to investigate epigenetic mechanisms responsible for CD10 negativity. Methods: CD10-negative infant ALL with MLL/AF4, CD10-positive infant ALL with germ-line MLL, CD10-positive pre-B ALL cell line, infant AML (M5) with MLL/AF9 and pediatric AML (M2) with AML1/ETO were analyzed for VDJH status and methylation of CD10 gene promoters. Results: Three of 4 cases with infant ALL revealed complete rearrangements of VDJH gene with productive joints. Bisulfite sequencing of CD 10 type 1 and 2 promoters identified more than 84% of methylated CpG dinucleotides in all three CD10-negative infant ALL cases with MLL/AF4. The CpG dinucleotides distributed in the clusters of putative Sp 1 binding sites and functionally active regulatory regions of the promoters were fully methylated. In contrast, none or a few of the CpG dinucleotides were methylated in the CD10-positive ALL, AML (M5) with MLL/AF9 or AML (M2) with AML1/ETO. Conclusions: Structural evidence of dense methylation in the CD 10 gene promoter suggested that methylated transcription factor binding sites contribute to CD10 silencing as an epigenetic mechanism. [Table: see text]

No significant financial relationships to disclose.

Analysis of T cell receptor Vbeta diversity in peripheral CD4 and CD8 T lymphocytes in patients with autoimmune thyroid diseases

Autoimmune thyroid diseases are characterized by intrathyroidal infiltration of CD4(+) and CD8(+) T lymphocytes reactive to self-thyroid antigens. Early studies analysing T cell receptor (TCR) Valpha gene usage have shown oligoclonal expansion of intrathyroidal T lymphocytes but not peripheral blood T cells. However, TCR Vbeta diversity of the isolated CD4(+) and CD8(+) T cell compartments in the peripheral blood has not been characterized fully in these patients. We performed complementarity-determining region 3 (CDR3) spectratyping as well as flow cytometric analysis for the TCR Vbeta repertoire in peripheral CD4(+) and CD8(+) T cells from 13 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis. Polyclonal TCR Vbeta repertoire was demonstrated by flow cytometry in both diseases. In contrast, CDR3 spectratyping showed significantly higher skewing of TCR Vbeta in peripheral CD8(+) T cells but not CD4(+) T cells among patients with Hashimoto's thyroiditis compared with healthy adults. We found trends towards a more skewed CDR3 size distribution in those patients having disease longer than 5 years and requiring thyroid hormone replacement. Patients with Graves' disease exhibited no skewing both in CD4(+) and CD8(+) T cells. These findings indicate that clonal expansion of CD8(+) T cells in Hashimoto's thyroiditis can be detected in peripheral blood and may support the role of CD8(+) T cells in cell-mediated autoimmune attacks on the thyroid gland in Hashimoto's thyroiditis.

Clonal relationship between infiltrating immunoglobulin G4 (IgG4)-positive plasma cells in lacrimal glands and circulating IgG4-positive lymphocytes in Mikulicz's disease

Mikulicz's disease (MD) is gaining acceptance as an immunoglobulin G4 (IgG4)-related disease characterized by bilateral lacrimal and salivary gland swelling. The aetiology of MD and other IgG4-related diseases is still unclear. The present work was performed to study the clonality of infiltrating IgG4-positive plasma cells in lacrimal glands and circulating peripheral blood cells in patients with MD, and compare the clonal relationship between infiltrating and circulating IgG4 positive cells. Total cellular RNA was extracted from the lacrimal glands and peripheral blood in five MD patients. Reverse transcription polymerase chain reaction was performed with primers specific for activation-induced cytidine deaminase (AID) and for Ig VH and IgG4. Sequences of Ig VH were compared with the structure of Ig VH of the lacrimal glands and the peripheral blood cells. AID was expressed to varying degrees in lacrimal glands of all MD patients. Most IgG4-positive cells infiltrating lacrimal glands and in peripheral blood were polyclonal, although several clonally related pairs were detected. In one patient, two of the circulating IgG4 VH4-59 clones shared identical CDR3 sequences with the clones within the lacrimal glands. In conclusion, while most tissue-infiltrating and circulating IgG4-positive cells in MD are polyclonal, some clonally related IgG4 positive cells exist between lacrimal gland and peripheral blood, accounting for the clinical features of MD as an IgG4-related disease involving multiple organs.

Clonotypic analysis of T cell reconstitution after haematopoietic stem cell transplantation (HSCT) in patients with severe combined immunodeficiency

Haematopoietic stem cell transplantation (HSCT) is performed for treatment of a broad spectrum of illnesses. Reconstitution of an intact immune system is crucial after transplantation to avoid infectious complications, and above all, the establishment of T cell receptor (TCR) diversity is the most important goal in the procedure. Until recently, little has been known of the mechanism of T cell reconstitution in the very early period after HSCT. In this study, we analysed TCR repertoires sequentially in four patients with severe combined immunodeficiency (SCID) before and after HSCT. In all patients, the TCR repertoires were extremely abnormal before HSCT, whereas after transplantation there was progressive improvement in TCR diversity, based on analysis of the TCR Vbeta repertoire and CDR3 size distributions. Somewhat unexpectedly, there was a significant but transient expansion of TCR diversity 1 month after transplantation in all cases. Clonotypic analysis of TCRs performed in one case showed that many T cell clones shared identical CDR3 sequences at 1 month and that the shared fraction decreased progressively. These results indicate that early expansion of TCR diversity may reflect transient expansion of pre-existing mature T cells from the donor blood, independent of de novo T cell maturation through the thymus.

Neuromyelitis optica associated with myasthenia gravis: characteristic phenotype in Japanese population

We report two female patients with neuromyelitis optica (NMO, Devic's syndrome) following or coincidental with myasthenia gravis (MG). Their illnesses were characterized by subacute myelitis with optic neuritis, high serum levels of muscle acetylcholine receptor antibody, and autoimmune thyroid disease. Both patients fulfilled the clinical criteria of NMO, however, NMO-IgG, autoantibody against aquaporin-4 water channel, was absent from their sera. Both NMO and MG are relatively rare diseases. The considerable coincidence of these two disorders suggests that there is a subgroup of patients with NMO having a common immunological pathogenesis with MG.

Selective expansion of CD16highCCR2- subpopulation of circulating monocytes with preferential production of haem oxygenase (HO)-1 in response to acute inflammation

Monocytes are composed of two distinct subpopulations in the peripheral blood as determined by their surface antigen expressions, profiles of cytokine production and functional roles played in vivo. We attempted to delineate the unique functional roles played by a minor CD16(high)CCR2(-) subpopulation of circulating monocytes. They produced significant levels of interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha, but very low levels of IL-10 upon in vitro stimulation. Characteristic profiles of cytokine production were confirmed by stimulating purified subpopulations of monocytes after cell sorting. It was noteworthy that freshly isolated CD16(high)CCR2(-) monocyte subpopulations produced significant levels of haem oxygenase (HO)-1, whereas the major CD16(low)CCR2(+) subpopulation produced little. These results were contrary to the generally accepted notion that the CD16(high)CCR2(-) monocyte subpopulation plays a predominantly proinflammatory role in vivo. The CD16(high)CCR2(-) subpopulation increased in Kawasaki disease and influenza virus infection. In accord with this, HO-1 mRNA expression by mononuclear cells was significantly increased in these illnesses. These results indicate that CD16(high)CCR2(-) subpopulations are of a distinct lineage from CD16(low)CCR2(+) monocytes. More importantly, they may represent a monocyte subpopulation with a unique functional role to regulate inflammation by producing HO-1 in steady state in vivo.

Treatment with low-dose angiotensin-converting enzyme inhibitor (ACEI) plus angiotensin II receptor blocker (ARB) in pediatric patients with IgA nephropathy

AIM

IgA nephropathy associated with heavy proteinuria is considered a more progressive form of this disease. In this report, we describe the favorable clinical effect of combination therapy with low doses of an angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) in the chronic stage of pediatric IgA nephropathy associated with heavy proteinuria.

PATIENTS

We initially used ACEI for seven children with IgA nephropathy and heavy proteinuria who did not achieve remission with the routine treatment including steroids.

RESULTS

With ACEI therapy alone, only three patients showed an antiproteinuric response. In one of the three patients, the proteinuria decreased by half, but was still over 1 g/day. In the other four patients, the proteinuria did not decrease. In these five patients, of whom one partial was a responder and four were non-responders for ACEI, ARB was added, and in marked contrast to ACEI therapy alone, the antiproteinuric effect was significantly augmented (p < 0.01). The antiproteinuric response induced by combination therapy was not accompanied by blood pressure changes. Urinary low-molecular protein and N-acetyl-beta-D-glucosaminidase (NAG) levels tended to decrease after both ACEI alone and combination therapy.

CONCLUSION

These data indicate that inhibition therapy of the angiotensin system not only decreases proteinuria levels but also protects renal tubular cells. Moreover, there were no obvious side effects associated with this therapy during the follow-up period of our clinical trial. In conclusion, this report shows that the combination of low doses of ACEI and ARB might provide marked antiproteinuric and long-term renoprotective effects in pediatric IgA nephropathy, with this approach appearing to be both well-tolerated and safe.

Oxidation of hemoglobin by lipid hydroperoxide associated with low-density lipoprotein (LDL) and increased cytotoxic effect by LDL oxidation in heme oxygenase-1 (HO-1) deficiency

Heme-catalyzed oxidation of low-density lipoprotein (LDL) is one of the relevant mechanisms involved in LDL modification. We previously revealed a substantial oxidation of plasma hemoglobin to methemoglobin and a subsequent heme-catalyzed LDL oxidation generating moieties toxic to endothelium in heme oxygenase-1 (HO-1)-deficiency in human. Drawing upon our previous observation we posited a pathway for oxidation of plasma hemoglobin in the HO-1-deficient child involving LDL-associated lipid hydroperoxide. In support, LDL-associated lipid hydroperoxide oxidized ferrohemoglobin to methemoglobin--known to readily release its heme moieties--in a dose-dependent manner. Repeated heme exposure of the child s LDL further increased its lipid hydroperoxide content within min leading to additional cytotoxic effect on endothelium. Both cytotoxicity and HO-1 inducing ability of the oxidized LDL were strongly dependent on its lipid hydroperoxide content. We wondered if cells of the HO-1-deficient patient were prone to oxidative damage arising from heme-mediated oxidation of LDL. Indeed, we found elevated cytotoxicity induced by heme-catalyzed oxidation of LDL in lymphoblastoid cells derived from the HO-1-deficient patient. We conclude that oxidation of hemoglobin to methemoglobin by LDL-associated lipid hydroperoxide and increased sensitivity of cells of the HO-1-deficient child to stress of oxidized LDL might contribute to the vascular disorders reported earlier.

Expansion and activation of minor histocompatibility antigen HY-specific T cells associated with graft-versus-leukemia response

The immune system of females is capable of recognizing and reacting against the male-specific minor histocompatibility antigen (mHA), HY. Thus, cytotoxic T-lymphocytes (CTLs) recognizing this antigen may be useful in eradicating leukemic cells of a male patient if they can be generated in vivo or in vitro from a human leukocyte antigen (HLA)-identical female donor. The HLA-A*0201-restricted HY antigen, FIDSYICQV, is a male-specific mHA. Using HLA-A2/HY peptide tetrameric complexes, we reveal a close association between the emergence of HY peptide-specific CD8(+) T cells in peripheral blood and molecular remission of relapsed BCR/ABL(+) chronic myelogenous leukemia in lymphoid blast crisis in a patient who underwent female-to-male transplantation. Assessment of intracellular cytokine levels identified T cells that produce interferon-gamma in response to the HY peptide during the presence of HY tetramer-positive T cells. These results indicate that transplant with allogeneic HY-specific CTLs has therapeutic potential for relapsed leukemia, and that expansion of such T cells may be involved in the development of a graft-versus-leukemia response against lymphoblastic leukemia cells.

Oligoclonal expansion of circulating and tissue-infiltrating CD8+ T cells with killer/effector phenotypes in juvenile dermatomyositis syndrome

Although triggering by infectious agents and abnormal immune responses may play some role in the pathogenesis of juvenile dermatomyositis syndrome (JDMS), the precise mechanism of muscle destruction and vascular damage is largely unknown. In this study, we tried to elucidate the role of cytotoxic T cells in two patients with JDMS, who were diagnosed based on the characteristic symptoms, laboratory data, MRI findings and electromyographic patterns. Peripheral blood T cell phenotypes were determined by flow cytometry, using mAbs against specific T cell receptor (TCR) Vbetas. Complementarity-determining region3 (CDR3) size analysis was performed by gene scanning of CDR3 polymerase chain reaction (PCR) amplification products specific for each Vbeta. Subsequently, CDR3 nucleotide sequences were obtained after cloning of the predominant products. The distribution of lymphocytes infiltrating the muscle tissue was analysed by immunohistochemistry. In both patients examined, a unique combination of TCR Vbeta repertoires was increased within the CD8+ T cells. These subpopulations expressed a characteristic phenotype, indicating that they are memory/effector T cells with killer functions. At the same time, immunohistological and molecular biological examinations of the biopsied muscle samples revealed that identical CD8+ T cell clones with identical phenotypes/TCR Vbeta infiltrated within the inflammatory tissue, in particular around vessels. These findings indicate that oligoclonal expansion of CD8+ T cells plays a central role in the pathogenesis of muscle injury in the juvenile form of dermatomyositis syndrome and may provide a useful clinical parameter of disease activity and responsiveness to anti-inflammatory therapy.

Cytoprotective role of heme oxygenase (HO)-1 in human kidney with various renal diseases

BACKGROUND

We previously reported that glomerular changes in the renal specimen of a human case with heme oxygenase-1 (HO-1) deficiency were mild, but tubulointerstitial injury advanced progressively. This study examined the patterns of HO-1 production in the kidney in various renal diseases. Furthermore, the critical cytoprotective roles of HO-1 were evaluated in the kidney by comparing HO-1 production and expressions of carboxymethyllysine (CML) and pentosidine, both of which are markers of oxidative stress.

METHODS

Renal biopsy or autopsy materials were obtained from a total of 74 patients. Degrees of hematuria and proteinuria and the levels of urinary N-acetyl-beta-D-glucosaminidase (NAG), beta2-microglobulin (beta2m), and creatinine were evaluated. Immunohistochemical studies for HO-1, CML, and pentosidine expressions were performed with their specific antiserum.

RESULTS

HO-1 staining was observed within tubular epithelial cells in all of the renal diseases, but was not detected within intrinsic glomerular cells. HO-1 staining tended to be more intense within distal tubuli than in proximal tubuli. Within distal tubuli, there was no significant correlation between intensity of HO-1 staining and degree of hematuria or presence of proteinuria. Within proximal tubuli, HO-1 staining tended to be more intense with greater degrees of hematuria, presence of proteinuria, and moderate tubulointerstitial damage. Intense staining of CML and pentosidine was observed within renal tubular epithelial cells only in HO-1-deficient patients.

CONCLUSIONS

HO-1 plays important roles in protecting renal tubuli from oxidative injuries, as these cells are constantly exposed to various oxidative stresses. It is suggested that renal tubular epithelia are more susceptible to oxidative stress due to the lack of this critical enzyme in HO-1 deficiency.

Differential cellular targets of Epstein-Barr virus (EBV) infection between acute EBV-associated hemophagocytic lymphohistiocytosis and chronic active EBV infection

Unusual Epstein-Barr virus (EBV) infection into T or natural killer cells plays a pivotal role in the pathogenesis of acute EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and chronic active EBV infection (CAEBV). The precise frequency and localization of EBV genome in lymphocyte subpopulations especially within T-cell subpopulations are unclear in these EBV-related disorders. This study analyzed the frequency of EBV-infected cells in circulating lymphocyte subpopulations from 4 patients with acute EBV-HLH and 4 with CAEBV. EBV- encoded small RNA-1 in situ hybridization examination of peripheral blood lymphocytes showed a significantly higher frequency of EBV-infected cells of 1.0% to 13.4% in EBV-HLH and 1.6% to 25.6% in CAEBV, respectively. The patterns of EBV infection in lymphocyte subpopulations were quite different between acute EBV-HLH and CAEBV. EBV infection was predominant in CD8(+) T cells in all EBV-HLH patients, whereas the dominant EBV-infected cell populations were non-CD8(+) lymphocyte subpopulations in CAEBV patients. Phenotypical analysis revealed that EBV-infected cell populations from both EBV-HLH and CAEBV were activated. There was no predominance of any EBV substrain of latent membrane protein-1, EBV-associated nuclear antigen (EBNA)-1, and EBNA-2 genes between the 2 abnormal EBV-associated disorders, and self-limited acute infectious mononucleosis. These results showing differential virus-cell interactions between acute EBV-HLH and CAEBV indicated different pathogenic mechanisms against EBV infection between the 2 EBV-associated diseases, which accounts for the difference in clinical manifestations between the 2 diseases.

Complete arrest from pro- to pre-B cells in a case of B cell-negative severe combined immunodeficiency (SCID) without recombinase activating gene (RAG) mutations

The B-cell lineage in a patient with B-cell-negative severe combined immunodeficiency (SCID) was analysed by using antisurrogate light chain (SL) MoAbs. Peripheral CD3(+) T cells and CD19(+) B cells were absent in the patient. The common gamma (gamma c) chain was expressed normally on the patient's peripheral NK cells and his peripheral mononuclear cells did not possess any mutations in recombinase activating gene (RAG)-1, 2. Normal levels of expression of Ku70 and Ku80 protein were found by Western blot analysis. The patient did, however, display an increase in fibroblast sensitivity to irradiation. Furthermore, flow cytometric analyses of bone marrow cells showed that surface IgM and cytoplasmic mu positive cells were absent and that CD19(+) B cells were composed of only CD34(+) terminal deoxynucleotidyl transferase (TdT)(+) SL(+) pro-B cells. The complete arrest of pro- to pre-B cell development in the SCID patient's bone marrow suggests that some genes involved in V(D)J recombination, excepting the RAG gene, may play a causative role in the immunodeficiency.

Human pancreatic cancer cells disable function of Fas receptors at several levels in Fas signal transduction pathway

The aims of this study were to evaluate the functional expression of Fas receptors (Fas) in human pancreatic cancer cell lines; Capan-1, AsPC-1, BxPC-3, PANC-1, and MIA PaCa-2 and to search for the mechanisms of receptor-mediated inhibition of Fas signaling in these cells. Despite the expression of Fas receptors at considerable levels, exposure of these cells to agonistic Fas antibodies (500 ng/ml) induced only minimal apoptosis in 4 cell lines. The mechanisms allowing resistance to Fas-mediated apoptosis are complex. Using RT-PCR, we identified molecules which might counteract the apoptogenic signal at several levels of Fas signal transduction pathway. The most striking findings were the overexpression of Fas decoy receptors (DcR3), Fas associated phosphatase-1 (FAP-1), and FLICE-inhibitory protein (c-FLIP) in the resistant cell lines as well as in pancreatic cancer surgical specimens. In conclusion, pancreatic cancer cells express three molecules that can abrogate Fas function at different levels of Fas signaling cascade, resulting in resistance to Fas-mediated apoptosis, and this may promote the progression of this malignancy.

Human pancreatic cancer cells express non-functional Fas receptors and counterattack lymphocytes by expressing Fas ligand; a potential mechanism for immune escape

The aim of this study was to investigate the expression and functional status of Fas ligand (FasL) and its receptor (Fas) in human pancreatic cancers. Using RT-PCR and Western blotting, Fas and FasL were expressed in seven surgically resected pancreatic cancer specimens and five cell lines; Capan-1, AsPC-1, BxPC-3, PANC-1, and MIA PaCa-2. In the resected specimens, pancreatic cancer cells induced apoptosis in the surrounding lymphoid cells. In coculture experiments of pancreatic cancer and Jurkat T cells, 50% of Jurkat T cells underwent apoptosis after 2 days, however, almost all pancreatic cancer cells remained viable. In addition, by testing Fas function using anti-Fas antibody (CH11), all cell lines were resistant to Fas-mediated apoptosis except Capan-1 cells which showed sensitivity similar to that of Jurkat T cells. These results suggest that pancreatic cancer cells evade immune surveillance by expression of FasL and non-functioning Fas that allow them to activated T-cells. These tumor escape mechanisms may contribute to the rapid fatal course of pancreatic cancer.

Structural evidence of genomic exon-deletion mediated by Alu-Alu recombination in a human case with heme oxygenase-1 deficiency

We previously reported a family affected by heme oxygenase-1 (HO-1) deficiency [Yachie et al., 1999]. The proband was a compound heterozygote for a complete loss of exon 2 (the maternal allele) and a two-nucleotide deletion within exon 3 (the paternal allele). In this report, we describe a large genomic deletion (1730 bp) including entire exon 2 in this family as a specific mechanism generating exon-2 absence observed in the HO-1 mRNA. Analysis of the deletion junction demonstrated fusion of a 5' portion of Alu-Sx element with a 3' portion of Alu-Sq element. The junction contained sequences with high homology to the recombinogenic Alu "core" sequence. These structural features of the HO-1 gene suggest homologous recombination associated with Alu element. This study presents the initial characterization of the HO-1 gene defect causing a human case of HO-1 deficiency and provides the molecular basis for understanding this genetic disease.

N-ethylmaleimide-enhanced phosphatidylserine externalization of human pancreatic cancer cells and immediate phosphatidylserine-mediated phagocytosis by macrophages

The purpose of this study was to examine whether N-ethylmaleimide (NEM) can enhance phosphatidylserine (PS) externalization on the outer surface of cancer cells, and PS-externalized cancer cells can be phagocytosed immediately by macrophages. NEM could externalize PS of cancer cells in concentration- and time-dependent manners. When treated with 5 mM NEM for 1 h, 80% of the carcinoma cells externalized their PS. In phagocytosis assay, these cells were engulfed immediately by macrophages before undergoing apoptosis. These results suggest that NEM can immediately externalize PS of cancer cells, leading to their recognition and phagocytosis by macrophages before undergoing apoptosis morphologically.

Tubular injury as a cardinal pathologic feature in human heme oxygenase-1 deficiency

Heme oxygenase (HO) catalyzes degradation of heme to biliverdin, iron, and carbon monoxide. It consists of three isoforms: an inducible form (HO-1), a constitutive form (HO-2), and the third isoform (HO-3), with properties similar to HO-2. There is limited evidence to suggest that the induction of HO-1 may have anti-inflammatory effects in an in vivo model of oxidative stress-mediated renal injury. We experienced the first human case of HO-1 deficiency. The patient had persistent proteinuria and hematuria, with biochemical evidence of renal tubular injury. We obtained three consecutive renal specimens: two from renal biopsies at 2 and 5 years of age and the third from autopsy at 6 years of age. The patient had systemic vascular endothelial-cell injury with massive intravascular hemolysis. The serum was loaded with heme and a large amount of heme-conjugated haptoglobin. A high concentration of haptoglobin was also detectable in urine. Mesangial proliferation or change in glomerular capillary-wall thickness was relatively mild to moderate in all specimens. Electron microscopic examination showed widespread endothelial detachment and subendothelial deposits of an unidentifiable material. It was striking that tubulointerstitial injury, with tubular dilatation and/or atrophy, interstitial fibrosis, and inflammatory cell infiltration, advanced progressively. Tubular epithelial cells were injured, and massive deposition of iron and haptoglobin was detectable. Bowman's capsules were dilated significantly, probably secondary to the collapse of atrophic tubuli. This is the first report to show that HO-1 has critical roles in vivo in protecting renal tubuli, in addition to vascular endothelium, from oxidative injury.

Diminished expression of CD59 on activated CD8+ T cells undergoing apoptosis in systemic lupus erythematosus and Sjögren's syndrome

The present study was undertaken to examine the phenotype of T cells undergoing in vitro apoptosis in patients with autoimmune diseases such as systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS). Compared with normal controls, we found diminished expression of CD59 antigen (one of the cell-surface complement-regulatory proteins) on CD8+ T cells, but not on CD4+ T cells, from patients with SLE and SS. Three-colour immunofluorescence analysis revealed that these CD59dim CD8+ T cells were activated T cells, expressing both human leucocyte antigen (HLA)-DR and CD45RO antigens. In addition, these CD59dim CD8+ T cells were more susceptible to in vitro apoptosis than CD59bright CD8+ T cells. In two patients with active lupus, the percentage of CD59dim CD8+ T cells was significantly decreased after steroid therapy. These findings suggest that decreased expression of CD59 antigen on in vivo-activated CD8+ T cells may be correlated with disease activity and may be involved in activation-induced apoptosis in patients with SLE and SS.

Coexistence of lymphoblastic and monoblastic populations with identical mixed lineage leukemia gene rearrangements and shared immunoglobulin heavy chain rearrangements in leukemia developed in utero

Congenital leukemia often provides insight into mechanisms of in utero leukemogenesis. A 10-day-old boy with clinical features of skin nodules, marked hepatosplenomegaly, and subcutaneous bleeding received a diagnosis of congenital leukemia. This patient initially had a dominant B progenitor lymphoblast population and minor monocyte component. Treatment with prednisolone, vincristine, and doxorubicin resulted in a loss of lymphoblast population and a rapid increase and dominance of the monocyte component within 10 days. Complete remission initially was obtained with additional combination chemotherapy with epipodophyllotoxin (VP-16) and cytosine arabinoside (Ara-C), but relapse characterized by a lymphoblastic population in the bone marrow was subsequently observed. The authors hypothesize that the leukemic cells originated from a common B-monocyte lineage stem cell during fetal hematopoiesis.

Characterization of immune function and analysis of RAG gene mutations in Omenn syndrome and related disorders

Omenn syndrome was recently found to be caused by missense mutations in RAG1 or RAG2 gene that result in partial V(D)J recombination activity. Although the clinical hallmarks of the disease are well defined, there have been several cases with clinical findings similar to, but distinct from Omenn syndrome. The data on immune functions and RAG gene mutations of such cases are limited. We described five Japanese infants from four unrelated families, including two cases of Omenn syndrome and three cases of related disorders. Sibling cases with typical Omenn phenotype were found to be compound heterozygotes of R396C and L885R mutations in RAG1. The former has been reported in European cases and may constitute a hot spot. The latter is a novel missense mutation. Infants with related disorders exhibited erythroderma, eosinophilia, hypogammaglobulinaemia, decreased number of B cells and skewing to Th2, and their lymph node specimens showed architectural effacement, lymphocyte depletion and histiocytic hyperplasia, each of which is seen characteristically in Omenn syndrome. However, in these cases serum IgE levels were low or undetectable. We found no mutation in RAG genes except for a K820R substitution in RAG1, which was regarded to be a functional polymorphism, in two of these cases. Our study suggests that RAG missense mutation may be a genetic abnormality unique to Omenn syndrome with characteristic clinical and laboratory findings. Variations of Omenn syndrome, or related disorders, may represent a different type of immunodeficiency, distinct from abnormalities in lymphoid-specific recombinase activity.

Age-dependent increase of IgE-binding and FcepsilonRI expression on circulating basophils in children

Peripheral blood basophils are sparse in the circulation, but they express high-affinity receptors for IgE (FCepsilonRI) and bind IgE efficiently. The present study was performed to elucidate the role of IgE bound on the basophil surface in the development of allergic responses during infancy and early childhood. IgE-binding and FcepsilonRI expression on basophils were evaluated by two-color flow cytometry. Basophil-bound IgE increased rapidly and reached adult levels during infancy in atopic patients, while it gradually increased with advancing age in parallel with serum IgE in normal controls. IgE-binding and FcepsilonRI expression in atopic children were higher than in normal controls among various age groups. They correlated with serum IgE levels but reached a plateau when serum IgE exceeded 300 ng/mL. A low, but significant level of FcepsilonRI expression was observed on cord blood basophils, although IgE-binding was usually undetectable. Incubation of cord blood with IgE rapidly saturated the preexisting IgE receptors and basophil-bound IgE levels increased. When neonatal basophils were cultured for 48 h with IgE, FcepsilonRI expression was upregulated dose-dependently and IgE-binding increased further. The up-regulation of FcepsilonRI was completely inhibited by cycloheximide, indicating that it was dependent on de novo protein synthesis. These results suggest that IgE-binding on basophils serves as a sensitive indicator of allergic sensitization, and that IgE functions as a positive regulator of FcepsilonRI expression in vivo.

Development of EBV-positive T-cell lymphoma following infection of peripheral blood T cells with EBV

Chronic active Epstein-Barr virus (EBV) infection is manifested clinically by the persistence of infectious mononucleosis-like symptoms or its complications for a prolonged period ranging from one to several years. This syndrome may include severe disease manifestations and can be fatal. The role of EBV in the pathogenesis of chronic active EBV infection has been unclear. We investigated two Japanese patients with severe chronic active EBV infection who subsequently developed EBV-positive T-cell lymphoma. We found that the patients had evidence of EBV infection in the peripheral blood CD4+ T-cells 19 and 3 months, respectively, before the T-cell lymphoma was diagnosed. The lymphomas were infected with monoclonal EBV and expressed the EBV latency genes EBNA-1, LMP-1, and LMP-2A, a virus latency pattern referred to as latency II. Genetic studies showed that the virus detected in the T-cell lymphoma was indistinguishable from the virus in the peripheral blood CD4+ T-cells. These studies support an important pathogenetic role of T-cell infection with EBV in chronic active EBV infection and in the EBV-positive T-cell lymphoma that followed.

Activated lansoprazole inhibits cancer cell adhesion to extracellular matrix components

Integrins play an important role in tumor dissemination. The purpose of this study was to examine whether a SH-reactive reagent inhibits the adhesion of the human pancreatic cancer cell line AsPC-1 to extracellular matrix components. Activated lansoprazole (AG-2000) was used as the SH-reactive reagent because this compound is known to react with SH groups but does not permeate the cell membrane. The effect of AG-2000 on the adhesion of AsPC-1 cells to matrix was examined, using both an in vitro adhesion assay and an in vivo nude mouse xenograft model of peritoneal implantation. In the in vitro adhesion assay, a 60-min exposure of AsPC-1 cells to AG-2000 resulted in a dose-dependent inhibition of AsPC-1 cell adhesion to laminin, fibronectin and type IV collagen, although AG-2000 did not affect the viability of AsPC-1 cells by MTT assay. In the in vivo assessment of AsPC-1 cell implantation, the AsPC-1 cells were initially preincubated with AG-2000 for 60 min to ensure adequate exposure of the AsPC-1 cells to AG-2000 before intraperitoneal injection. AG-2000 significantly inhibited the peritoneal implantation of the AsPC-1 cells in nude mice. These findings suggest that a short exposure of cancer cells to AG-2000 can inhibit cancer cell adhesion to extracellular matrix components.

Characterization of T-cell repertoire of the bone marrow in immune-mediated aplastic anemia: evidence for the involvement of antigen-driven T-cell response in cyclosporine-dependent aplastic anemia

To determine whether the antigen-driven T-cell response is involved in the pathogenesis of aplastic anemia (AA), we examined the complementarity-determining region 3 (CDR3) size distribution of T-cell receptor (TCR) beta-chain (BV) subfamilies in the bone marrow (BM) of untreated AA patients. AA patients who did not respond to immunosuppressive therapy and those who obtained unmaintained remission early after cyclosporine (CyA) or antithymocyte globulin (ATG) therapy exhibited essentially a normal CDR3 size pattern. In contrast, five patients who needed continuous administration of CyA to maintain remission exhibited a skewed CDR3 size pattern in a number (>40%) of BV subfamilies suggestive of clonal predominance. The skewing of CDR3 size distribution became less pronounced in one of the CyA-dependent patients when the patient achieved unmaintained remission after a 4-year therapy with CyA, whereas it persisted longer than 7 years in the other patient requiring maintenance therapy. Sequencing of BV15 cDNA for which the CDR3 size pattern exhibited apparent clonal predominance in all CyA-dependent patients showed high homology of the amino acid sequence of the CDR3 between two different patients. These findings indicate that antigen-driven expansion of T cells is involved in the pathogenesis of AA characterized by CyA-dependent recovery of hematopoiesis.

Administration of G-CSF to normal individuals diminishes L-selectin+ T cells in the peripheral blood that respond better to alloantigen stimulation than L-selectin- T cells

To determine whether administration of G-CSF induces phenotypic or functional changes in T cells, we examined peripheral blood T cells from normal individuals receiving G-CSF for activation antigen and adhesion molecule expression before and after G-CSF administration. G-CSF (10 microg/kg/day) was administered subcutaneously to 14 normal individuals for 3-5 days and their PBMC were serially analyzed with monoclonal Ab (mAb) directed to HLA-DR, CD45RO, CD45RA, CD25, CD122, CD95, CD11a, CD49d, CD44 and CD62L (L-selectin) coupled with anti-CD3 mAb. Among T cells positive for these antigens, only the proportion of T cells expressing L-selectin significantly decreased from 68% to 37% after 3-day G-CSF administration. When peripheral blood CD3+ T cells obtained before and after G-CSF administration were sorted into two populations depending on the expression of L-selectin and tested for their proliferative response to allogeneic B cells, the reactivity of L-selectin- cells to alloantigen stimulation was consistently lower than that of L-selectin+ cells regardless of the exposure to G-CSF. The decrease in the relative number of L-selectin+ cells induced by G-CSF administration may contribute to the unexpectedly low incidence of severe acute GVHD after allogeneic PBSC transplantation.

Oxidative stress causes enhanced endothelial cell injury in human heme oxygenase-1 deficiency

The first known human case of heme oxygenase-1 (HO-1) deficiency is presented in this report. The patient is a six-year-old boy with severe growth retardation. He has been suffering from persistent hemolytic anemia characterized by marked erythrocyte fragmentation and intravascular hemolysis, with paradoxical increase of serum haptoglobin and low bilirubin. An abnormal coagulation/fibrinolysis system, associated with elevated thrombomodulin and von Willebrand factor, indicated the presence of severe, persistent endothelial damage. Electron microscopy of renal glomeruli revealed detachment of endothelium, with subendothelial deposition of an unidentified material. Iron deposition was noted in renal and hepatic tissue. Immunohistochemistry of hepatic tissue and immunoblotting of a cadmium-stimulated Epstein-Barr virus-transformed lymphoblastoid cell line (LCL) revealed complete absence of HO-1 production. An LCL derived from the patient was extremely sensitive to hemin-induced cell injury. Sequence analysis of the patient's HO-1 gene revealed complete loss of exon-2 of the maternal allele and a two-nucleotide deletion within exon3 of the paternal allele. Growth retardation, anemia, iron deposition, and vulnerability to stressful injury are all characteristics observed in recently described HO-1 targeted mice. This study presents not only the first human case of HO-1 deficiency but may also provide clues to the key roles played by this important enzyme in vivo.

Increasing prevalence of ampicillin- resistant, non-beta-lactamase-producing strains of Haemophilus influenzae in children in Japan

Among Haemophilus influenzae isolated from children with respiratory tract infections, the evolution of ampicillin resistance was investigated during 1996 and 1997 in Japan. beta-Lactamase production was assessed and minimum inhibitory concentrations (MICs) of eight antimicrobial agents were determined using a broth microdilution method in Mueller-Hinton-lysed horse blood medium. Of 74 H. influenzae, 11 strains (14.9%) produce beta-lactamase and were thus highly resistant to ampicillin (MIC of >4.0 microgram/ ml). In addition, moderate resistance to ampicillin, defined as an MIC of >==1.0 microgram/ml, was noted in 44.4% of all beta-lactamase-negative isolates. These beta-lactamase-negative ampicillin-resistant (BLNAR) organisms were resistant to other cephalosporins such as cefpodoxime and cefdinir, while beta-lactamase-producing strains were susceptible to them. Cefditoren, cefteram, and minocycline were active against all strains studied, whereas cefaclor and clarithromycin were inactive against all H. influenzae isolates in this study. Results indicate that BLNAR strains have emerged among children with respiratory tract infections in Japan.

CD27/CD70 interaction augments IgE secretion by promoting the differentiation of memory B cells into plasma cells

The induction of IgE switching in B cells requires several signals given by cytokines and cell contact-delivered signals. Here, we investigated the role of CD27/CD70 interaction in B cell IgE synthesis. The addition of CD27 ligand (CD70) transfectants to B cell cultures increased the IgE synthesis synergistically in the presence of IL-4 plus anti-CD40 mAb (anti-CD40). The effect of CD70 transfectants was dose dependent and was completely blocked by anti-CD70 mAb. CD27+ B cells had the ability to produce IgE, which was increased by contact with CD70 transfectants, whereas CD27- B cells did not produce IgE. CD27/CD70 interaction enhanced B cell proliferation in the presence of IL-4 or IL-4 plus anti-CD40. The augmentation of B cell proliferation by CD70 transfectants was apparent in CD27+ B cells, but was mild in CD27- B cells. The helper activity for IgE synthesis by the CD27/CD70 interaction did not contribute to the enhancement of germline epsilon transcripts. Flow cytometric and morphological analyses demonstrated that the addition of CD70 transfectants to B cell cultures remarkably promoted differentiation into plasma cells in the presence of IL-4 and CD40 signaling. Finally, CD27 cross-linking resulted in the up-regulation of positive regulatory domain I-binding factor-1. Taken together, our findings indicate that signaling via CD27 on B cells induces IgE synthesis, in cooperation with IL-4 and CD40 signaling, by promoting the generation of plasma cells through up-regulation of positive regulatory domain I-binding factor-1.