An input-controlled model system for identification of MHC bound peptides enabling laboratory comparisons of immunopeptidome experiments

Characterization of MHC-bound peptides by mass spectrometry (MS) is an essential technique for immunologic studies. Many efforts have been made to quantify the number of MHC-presented ligands by MS and to define the limits of detection of a specific MHC ligand. However, these experiments are often complex and comparisons across different laboratories are challenging. Therefore, we compared and orthogonally validated quantitation of peptide:MHC complexes by radioimmunoassay and flow cytometry using TCR mimic antibodies in three model systems to establish a method to control the experimental input of peptide MHC:complexes for MS analysis. Following isolation of MHC-bound peptides we identified and quantified an MHC ligand of interest with high correlation to the initial input. We found that the diversity of the presented ligandome, as well as the peptide sequence itself affected the detection of the target peptide. Furthermore, results were applicable from these model systems to unmodified cell lines with a tight correlation between HLA-A*02 complex input and the number of identified HLA-A*02 ligands. Overall, this framework provides an easily accessible experimental setup that offers the opportunity to control the peptide:MHC input and in this way compare immunopeptidome experiments not only within but also between laboratories, independent of their experimental approach. SIGNIFICANCE: Although immunopeptidomics is an essential tool for the characterization of MHCbound peptides on the cell surface, there are no easily applicable established protocols available that allow comparison of immunopeptidome experiments across laboratories. Here, we demonstrate that controlling the peptide:MHC input for immunopurification and LC-MS/MS experiments by flow cytometry in pre-defined model systems allows the generation of qualitative and quantitative data that can easily be compared between investigators, independently of their methods for MHC ligand isolation for MS.

Characterization of a novel HLA-C allele, HLA-C*04:288, in an Italian patient

The novel HLA-C*04:288 differs from HLA-C*04:01:01:06 by a single nucleotide substitution in exon 2.

Identification of two new HLA class I alleles in Italian bone marrow donors: A*31:125 and B*44:269

Two novel alleles, HLA-A*31:125 and HLA-B*44:269, are described in Italian bone marrow donors.

A therapeutic T cell receptor mimic antibody targets tumor-associated PRAME peptide/HLA-I antigens

Preferentially expressed antigen in melanoma (PRAME) is a cancer-testis antigen that is expressed in many cancers and leukemias. In healthy tissue, PRAME expression is limited to the testes and ovaries, making it a highly attractive cancer target. PRAME is an intracellular protein that cannot currently be drugged. After proteasomal processing, the PRAME300-309 peptide ALYVDSLFFL (ALY) is presented in the context of human leukocyte antigen HLA-A*02:01 molecules for recognition by the T cell receptor (TCR) of cytotoxic T cells. Here, we have described Pr20, a TCR mimic (TCRm) human IgG1 antibody that recognizes the cell-surface ALY peptide/HLA-A2 complex. Pr20 is an immunological tool and potential therapeutic agent. Pr20 bound to PRAME+HLA-A2+ cancers. An afucosylated Fc form (Pr20M) directed antibody-dependent cellular cytotoxicity against PRAME+HLA-A2+ leukemia cells and was therapeutically effective against mouse xenograft models of human leukemia. In some tumors, Pr20 binding markedly increased upon IFN-γ treatment, mediated by induction of the immunoproteasome catalytic subunit β5i. The immunoproteasome reduced internal destructive cleavages within the ALY epitope compared with the constitutive proteasome. The data provide rationale for developing TCRm antibodies as therapeutic agents for cancer, offer mechanistic insight on proteasomal regulation of tumor-associated peptide/HLA antigen complexes, and yield possible therapeutic solutions to target antigens with ultra-low surface presentation.

Characterization of a novel HLA-B*18 variant allele, HLA-B*18:122, by genome sequencing

The HLA-B*18:122 allele showed four nucleotide differences from HLA-B*18:01:01:01.

Characterization of a novel HLA-DRB1 allele, HLA-DRB1*13:215, in an Italian bone marrow donor

One nucleotide substitution at residue 142 of the HLA-DRB1*13:01:01 results in a new allele, HLA-DRB1*13:215.

Glass-ceramic coated Mg-Ca alloys for biomedical implant applications

Biodegradable metals and alloys are promising candidates for biomedical bone implant applications. However, due to the high rate of their biodegradation in human body environment, they should be coated with less reactive materials, such, for example, as bioactive glasses or glass-ceramics. Fort this scope, RKKP composition glass-ceramic coatings have been deposited on Mg-Ca(1.4wt%) alloy substrates by Pulsed Laser Deposition method, and their properties have been characterized by a number of techniques. The prepared coatings consist of hydroxyapatite and wollastonite phases, having composition close to that of the bulk target material used for depositions. The 100μm thick films are characterized by dense, compact and rough morphology. They are composed of a glassy matrix with various size (from micro- to nano-) granular inclusions. The average surface roughness is about 295±30nm due to the contribution of micrometric aggregates, while the roughness of the fine-texture particulates is approximately 47±4nm. The results of the electrochemical corrosion evaluation tests evidence that the RKKP coating improves the corrosion resistance of the Mg-Ca (1.4wt%) alloy in Simulated Body Fluid.

Identification of a new HLA-A*24 allele, A*24:309, in an Italian bone marrow donor

A novel class I human leukocyte antigen allele HLA-A*24:309 is described.

Abstract A055: Potent therapeutic and immunological effects of the first T-BiTE derived from a TCR-mimic antibody targeting intracellular oncoprotein WT1

Bi-specific T cell engager antibody (BiTE) therapy has recently emerged as an effective immunotherapy by redirecting polyclonal T cell cytotoxicity against cell surface protein on tumor cells. We generated the first BiTE construct derived from a TCR-mimic monoclonal antibody (mAb), ESK1, specific for a peptide from an intracellular oncoprotein, WT1, in the context of HLA-A*02:01 molecules. Despite the low density peptide/HLA-A2 complex on the cell surface, ESK-BiTE was able to selectively activate and induce proliferation of cytolytic human T cells to kill multiple leukemias and cancers in vitro and in mice. Surprisingly, we also discovered that in an autologous setting, ESK-BiTE induced a robust secondary CD8 T cell response specific for antigens other than WT1, including HLA-A2-restricted her2-neu-derived peptide 369-377, in patients with her2- positive ovarian cancer. Therefore, the study demonstrated a new vaccinal mechanism for BiTE mAb action that could contribute to more effective long-term therapeutic activity of BiTE's and further broaden their reach to other tumor antigens not previously known or originally targeted.

Citation Format: Tao Dao, Dmitry Pankov, Andrew Scott, Tatyana Korontsvit, Victoriya Zakhaleva, Manuel Direito de Morais Guerrerio, Yiyang Xu, Jingyi Xiang, Su Yan, Nicholas Veomett, Nicholas Veomett, Leonid Dubrovsky, Michael Curcio, Ekaterina Doubrovina, Cheng Liu, Richard J. O'Reilly, David A. Scheinberg. Potent therapeutic and immunological effects of the first T-BiTE derived from a TCR-mimic antibody targeting intracellular oncoprotein WT1. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A055.

On demand delivery of ionic drugs from electro-responsive CNT hybrid films

Electro responsive hybrid hydrogel films able to precisely modulate the release of drugs as a function of their net charge.

Identification and characterization of a novel HLA-A allele, HLA-A*68:105, by genomic sequencing

A novel HLA-A allele, HLA-A*68:105, was detected by sequence-based typing (SBT) in an Italian bone marrow donor. It differs from HLA-A*68:01:02 at five nucleotides, three intronic, nt 699 T->G (intron 2), nt 705 T->C (intron 2) and nt 2770 G->A (intron 7), and two located in exon 3, at positions 726 A-G (codon 94 Ile->Val) and 733 T-G (codon 97 Arg->Met), respectively.

The influence of ictal cutaneous allodynia on the response to occipital transcutaneous electrical stimulation in chronic migraine and chronic tension-type headache: a randomized, sham-controlled study

OBJECTIVE

The objective of this article is to determine whether cutaneous allodynia (CA) influences the response to treatment with occipital transcutaneous electrical stimulation (OTES) in chronic migraine (CM) and chronic tension-type headache (CTTH).

METHODS

One hundred and sixty consecutive patients with CM or CTTH were randomized to be treated with real or sham OTES stimulation three times a day for two consecutive weeks. All patients completed the validated 12-item allodynia symptom checklist for assessing the presence and the severity of CA during headache attack. Primary end-point was change (≥50%) in number of monthly headache-free days.

RESULTS

There was a significant difference in the percentage of responders in the real OTES compared with sham OTES group (p <0.001). Importantly, there was not a significant change of monthly headache-free days in the allodynic patients with CM and CTTH treated both with real and sham OTES, while the number of headache-free days per month was significantly reduced in the real (86%) but not in the sham group (7%) of non-allodynic patients with CTTH and CM.

CONCLUSIONS

Severe CA is associated with decreased response to treatment with OTES in patients with CM and CTTH.

Therapeutic efficacy of an Fc-enhanced TCR-like antibody to the intracellular WT1 oncoprotein

PURPOSE

RMFPNAPYL (RMF), a Wilms' tumor gene 1 (WT1)-derived CD8 T-cell epitope presented by HLA-A*02:01, is a validated target for T-cell-based immunotherapy. We previously reported ESK1, a high avidity (Kd < 0.2 nmol/L), fully-human monoclonal antibody (mAb) specific for the WT1 RMF peptide/HLA-A*02:01 complex, which selectively bound and killed WT1(+) and HLA-A*02:01(+) leukemia and solid tumor cell lines.

EXPERIMENTAL DESIGN

We engineered a second-generation mAb, ESKM, to have enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) function due to altered Fc glycosylation. ESKM was compared with native ESK1 in binding assays, in vitro ADCC assays, and mesothelioma and leukemia therapeutic models and pharmacokinetic studies in mice. ESKM toxicity was assessed in HLA-A*02:01(+) transgenic mice.

RESULTS

ESK antibodies mediated ADCC against hematopoietic and solid tumor cells at concentrations below 1 μg/mL, but ESKM was about 5- to 10-fold more potent in vitro against multiple cancer cell lines. ESKM was more potent in vivo against JMN mesothelioma, and effective against SET2 AML and fresh ALL xenografts. ESKM had a shortened half-life (4.9 days vs. 6.5 days), but an identical biodistribution pattern in C57BL/6J mice. At therapeutic doses of ESKM, there was no difference in half-life or biodistribution in HLA-A*02:01(+) transgenic mice compared with the parent strain. Importantly, therapeutic doses of ESKM in these mice caused no depletion of total WBCs or hematopoetic stem cells, or pathologic tissue damage.

CONCLUSIONS

The data provide proof of concept that an Fc-enhanced mAb can improve efficacy against a low-density, tumor-specific, peptide/MHC target, and support further development of this mAb against an important intracellular oncogenic protein.

Identification of a novel HLA-B*15 variant allele, HLA-B*15:276, in an umbilical cord blood donor

A newly identified allele, named HLA B*15:276, differs from B*15:01:01:01 by the single nucleotide substitution 511T-C at codon 147 (Trp → Arg) in exon 3.

Targeting the intracellular WT1 oncogene product with a therapeutic human antibody

The Wilms tumor 1 (WT1) oncoprotein is an intracellular, oncogenic transcription factor that is overexpressed in a wide range of leukemias and solid cancers. RMFPNAPYL (RMF), a WT1-derived CD8+ T cell human leukocyte antigen (HLA)-A0201 epitope, is a validated target for T cell-based immunotherapy. Using phage display technology, we discovered a fully human "T cell receptor-like" monoclonal antibody (mAb), ESK1, specific for the WT1 RMF peptide/HLA-A0201 complex. ESK1 bound to several leukemia and solid tumor cell lines and primary leukemia cells, in a WT1- and HLA-A0201-restricted manner, with high avidity [dissociation constant (Kd)=0.1 nM]. ESK1 mediated antibody-dependent human effector cell cytotoxicity in vitro. Low doses of naked ESK1 antibody cleared established, disseminated, human acute lymphocytic leukemia and Philadelphia chromosome-positive leukemia in nonobese diabetic/severe combined immunodeficient γc-/- (NSG) mouse models. At therapeutic doses, no toxicity was seen in HLA-A0201 transgenic mice. ESK1 is a potential therapeutic agent for a wide range of cancers overexpressing the WT1 oncoprotein. This finding also provides preclinical validation for the strategy of developing therapeutic mAbs targeting intracellular oncogenic proteins.

Effects of long-term treatment with pioglitazone on cognition and glucose metabolism of PS1-KI, 3xTg-AD, and wild-type mice

In this study, we investigated the effects of long-term (9-month) treatment with pioglitazone (PIO; 20 mg/kg/d) in two animal models of Alzheimer's disease (AD)-related neural dysfunction and pathology: the PS1-KI(M146V) (human presenilin-1 (M146V) knock-in mouse) and 3xTg-AD (triple transgenic mouse carrying AD-linked mutations) mice. We also investigated the effects on wild-type (WT) mice. Mice were monitored for body mass changes, fasting glycemia, glucose tolerance, and studied for changes in brain mitochondrial enzyme activity (complexes I and IV) as well as energy metabolism (lactate dehydrogenase (LDH)). Cognitive effects were investigated with the Morris water maze (MWM) test and the object recognition task (ORT). Behavioral analysis revealed that PIO treatment promoted positive cognitive effects in PS1-KI female mice. These effects were associated with normalization of peripheral gluco-regulatory abnormalities that were found in untreated PS1-KI females. PIO-treated PS1-KI females also showed no statistically significant alterations in brain mitochondrial enzyme activity but significantly increased reverse LDH activity.PIO treatment produced no effects on cognition, glucose metabolism, or mitochondrial functioning in 3xTg-AD mice. Finally, PIO treatment promoted enhanced short-term memory performance in WT male mice, a group that did not show deregulation of glucose metabolism but that showed decreased activity of complex I in hippocampal and cortical mitochondria. Overall, these results indicate metabolically driven cognitive-enhancing effects of PIO that are differentially gender-related among specific genotypes.

Identification of a novel HLA-DRB1 allele through sequence-based typing of an Italian patient candidate for kidney transplant

In this report, we describe the identification of the novel HLA-DRB1*13:120 that differs from the closest matching allele HLA-DRB1*13:65 at two nucleotidic position in the exon 2.

Identification of a novel HLA-DRB1*11 variant allele, DRB1*1189

Here, we describe the identification of a novel human leukocyte antigen (HLA)-DRB1 allele, DRB1*1189, that was found in an Italian Caucasian individual. This sequence differs from HLA-DRB1*1134 by three nucleotide exchange at positions 286 (C-->T), 296 (A-->G), and 308 (C-->A) in exon 2.

Imprinted hydrophilic nanospheres as drug delivery systems for 5-fluorouracil sustained release

Molecularly imprinted hydrogel nanospheres as devices for the controlled/sustained release of 5-fluororacil in biological fluids were synthesized employing one-pot precipitation technique as the polymerization method. Methacrylic acid as a functional monomer and ethylene glycole dimethacrylate as a cross-linker were used in polymeric feed. Morphological and hydrophilic properties were determined by scanning electron microscopy and water content measurement, and recognition and selectivity properties of spherical molecularly imprinted polymers were compared with the spherical non-imprinted polymers, both in organic (acetonitrile) and water media. Finally, in vitro release studies were performed in plasma simulating fluids.

Molecularly imprinted solid phase extraction for the selective HPLC determination of α-tocopherol in bay leaves

A new sorbent for molecularly imprinted solid phase extraction (MISPE) was synthesized to extract and purify alpha-tocopherol (alpha-TP) from vegetable sources. Molecularly imprinted polymers (MIP) were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent using a photo-polymerization procedure. A thermo-polymerization was also performed but no imprinting effect in the resulting materials was raised. The proposed MISPE protocol could overcome the drawback of traditional detection methods, which require pre-treatments of the samples. The possibility to obtain the selective recognition of alpha-TP from natural samples in aqueous mixtures represents one of the main advantages of our materials. Our procedure involves the direct HPLC injection of eluate without any treatment and above all the use of no toxic and biocompatible organic solvents. After the evaluation of the selectivity of the alpha-TP imprinted polymers, the performance of these materials as solid phase extraction (SPE) sorbents was investigated. Our MISPE-HPLC procedure has a high sensitivity, LOD and LOQ were 3.49x10(-7) and 1.16x10(-6) mol L(-1), respectively, as well as good precision (intraday precision below 3.3% and interday precisions below 6.5%) and recovery (60%). Thus, it can be successfully used for the purification of alpha-TP from bay leaves.

Identification of a novel HLA-DRB3 allele, DRB3*020205, by sequence-based typing

The novel HLA allele DRB3*020205 (a synonymous G>T transition in exon 2) was identified in a European subject.

Impaired glucose metabolism in patients with acute stroke and no previous diagnosis of diabetes mellitus

BACKGROUND

About a third of patients with acute stroke and no prior diagnosis of diabetes have hyperglycaemia during the acute phase of stroke. Whether this is an acute stress response or a reflection of underlying diabetes is controversial.

AIM

To assess whether impaired glucose metabolism in patients with acute ischaemic stroke and no previous diagnosis of diabetes persists after 3 months, and whether such persistence can be predicted.

DESIGN

Prospective observational study.

METHODS

We enrolled 106 patients with acute ischaemic stroke and no history of diabetes. Fasting blood glucose, serum insulin and the insulin resistance index HOMA were recorded during hospital stay. A standard oral glucose tolerance test was performed at discharge and 3 months later.

RESULTS

Ten patients did not complete the study. Eighty-one patients (84.4%) had abnormal glucose metabolism at discharge and 62 (64.6%) after 3 months. Thirty-seven (38.5%) had impaired glucose tolerance at discharge and 26 (27.1%) after 3 months. Forty-four (45.8%) had diabetes at discharge, and 36 (37.5%) at 3 months. Post-load hyperglycaemia at discharge was a predictor of diabetes after 3 months. A plasma glucose cut-off of 11.7 mmol/l (210 mg/dl) had a specificity of 90.0% and a positive predictive value of 81.3%. HOMA increased progressively from patients with normal glucose metabolism to those with newly diagnosed diabetes.

DISCUSSION

Impaired glucose tolerance and previously unrecognized diabetes could be detected early in the stroke course, and persisted after 3 months in more than two-thirds of our patients. Post-load hyperglycaemia during the acute phase of stroke may be useful in identifying patients with abnormal glucose metabolism, which places them at risk for adverse outcomes, including cardiovascular disease.

Microgeographic variation of HLA-A, -B, and -DR haplotype frequencies in Tuscany, Italy: implications for recruitment of bone marrow donors

HLA-A/B haplotype frequencies were estimated in a sample of 2355 bone marrow donors born in a subregion of Tuscany (Italy), and the HLA-A, -B, -DR haplotype frequencies were estimated in a subset of 809 individuals. This area was divided in 10 subsamples (two-locus haplotypes), or six subsamples (three-locus haplotypes), all with sample size >50, based on administrative boundaries. A considerable level of heterogeneity of haplotype frequency was present among subsamples; this heterogeneity was associated to a large variation (up to 4-fold) of the number of new donors that must be typed in order to reach 50% chance of finding an HLA-A, -B phenotype of intermediate frequency. Knowledge of the genetic structure of the population at a microgeographic level may be useful in directing the search of specific bone marrow donors.

Non-tuberculous mycobacteria: patterns of isolation. A multi-country retrospective survey

OBJECTIVE

To collect data on non-tuberculous mycobacteria (NTM) isolated from clinical laboratories in different countries to establish: 1) whether the isolation of NTM was increasing, 2) which species were increasing, and 3) whether there was any pattern of geographical distribution.

DESIGN

In 1996, the Working Group of the Bacteriology and Immunology Section of the International Union Against Tuberculosis and Lung Disease contacted 50 laboratories in different countries for the necessary information.

RESULTS

The number of patients reported with NTM was 36099 from 14 countries. Mycobacterium avium complex, M. gordonae, M. xenopi, M. kansasii and M. fortuitum were the five species most frequently isolated. There was a significant upward trend for M. avium complex and M. xenopi. Pigmented mycobacteria predominated in Belgium, the Czech Republic and the Mediterranean coast of Spain. Non-chromogenic mycobacteria were found to be predominant in the area of the Atlantic coast of Brazil and in Turkey, the United Kingdom, Finland and Denmark.

CONCLUSIONS

There was an increase in the number of NTM isolated from clinical samples of patients. Isolation of the most frequent species is constantly changing in most of the geographical areas, and newer species are emerging due to better diagnostic techniques to detect and identify NTM.

Identification of a novel HLA-DPB1 allele, DPB1*9701, by sequence-based typing

This report describes the identification of a novel DPB1 allele, DPB *9701, found in an Italian Caucasian individual. The new allele was detected by human leukocyte antigen sequence-based typing carried out to investigate the role of genetic factors in determining the outcome of hepatitis C virus infection. DPB1*9701 was identical to DPB1*0501 except for a single-nucleotide substitution at codon 43 (GGG --> TGG). This nucleotide change is a non-synonymous mutation and results in the amino acid substitution glycine (G) --> tryptophan (W). The nucleotide sequence has been deposited in GenBank under the accession number AY033075, and denominated DPB1*9701 by the official World Health Organization Nomenclature Committee.

The benefits of a gynecologic oncologist: a pattern of care study for endometrial cancer treatment

OBJECTIVES

Compare important aspects of initial endometrial cancer treatment in women with or without primary management by a gynecologic oncologist (GYO).

METHODS

A retrospective pattern of care study was conducted using tumor registry data from a community-based health care system. Surgically treated endometrial cancer cases were reviewed with respect to histology, training of surgeon(s), procedures, TNM staging, and prescription of adjuvant radiation.

RESULTS

Two hundred and seven consecutive cases completed between January 1998 and December 2000 were analyzed. Overall surgical stage was 78.4% stage I, 6.9% stage II, and 14.7% stage III-IV. Gynecologic oncologists (GYOs) provided care in 101 (48.8%) and gynecologists (GYNs) in 104 cases (50.2%). General surgeons (GSs) assisted gynecologists in 36.5% of cases. GYOs (94.0%) completed TNM staging two times more frequently (P < 0.05) than GYNs (45.2%). The incidence of lymph node assessment by GYOs was 83.0% (average number of nodes, 19.5) and GYNs 26.0% (average number of nodes, 7.7). Advanced disease (stage III-IV) was more frequently (P < 0.05) managed by GYOs (23.0%) than GYNs (6.7%). Radiation (RT) was prescribed to 36 (17.4%) patients. When evaluating TI and TII tumors at risk for extrauterine spread (G2-G3 or myometrial invasion), GYOs completed surgical staging more frequently than GYNs (95.7% vs. 18.8%, P < 0.05). GYO patients received radiation (six patients: 8.6%) less frequently than GYN patients (8.6% vs. 21.7%). No patient managed by GYOs with T1 N0 disease received RT. Eighteen percent of patients managed by GYNs with T1 N0 or T1 NX received RT.

CONCLUSIONS

Gynecologic oncologists are more likely to evaluate and manage those with advanced endometrial cancer. Women with endometrial cancer managed by GYOs are more likely to receive comprehensive TNM surgical staging. The employment of complete TNM staging by GYOs reduced the use of RT in those with T1 N0 or Nx disease by 100%. These results suggest that primary management by gynecologic oncologists results in an efficient use of health care resources and minimized the potential morbidity associated with adjuvant radiation.

HLA-DR in couples associated with preeclampsia: background and updating by DNA sequencing

The placenta acts as an immunological barrier between the mother and the fetal "graft", allowing two antigenically different organisms to tolerate one another. In placentae from preeclamptic women, we have demonstrated, by an ultrastructural assessment and an immunohistochemical study, a placental barrier breakage leading to the mixing of maternal and fetal antigenically different blood. This condition could be responsible for the triggering of a maternal rejection reaction that we presume to be at the basis of the preeclamptic syndrome. Thus, we have investigated the Human Leukocyte class II DR antigens (HLA-DR), whose role in self and non-self recognition is well known, in women with preeclampsia, their partners and in control couples using the serological Terasaki tecnique. The results showed a statistically significant increase of HLA-DR homozygosity and a reduced antigenic variety in the preeclamptic women and their partners with respect to controls. In this update, we have examined the 2nd exon of the human gene, HLA-DRB1, on the short arm of the chromosome 6 using DNA sequence-based typing (S-BT) PCR in 56 preeclamptic couples and 64 control couples. The results have confirmed the significant excess of HLA-DR homozygosity in couples associated with preeclampsia versus controls. From our results, it emerges that HLA-DR homozygosity and the reduced antigenic variety seem to be associated to a major risk for preeclampsia, which further appears to be a "couple's disease".

Correlations of Y chromosome microchimerism with disease activity in patients with SLE: analysis of preliminary data

BACKGROUND

Recently it has been suggested that microchimerism may have a significant role in the aetiopathogenesis of some autoimmune diseases.

OBJECTIVES

To evaluate the incidence of microchimerism in systemic lupus erythematosus (SLE), to quantify the phenomenon, to evaluate changes of microchimerism during follow up, and to correlate these data with clinical and laboratory variables.

METHODS

Patients were selected for the study on the basis of the following criteria: (a) pregnancy with at least one male offspring; (b) no history of abortion and blood transfusion. Microchimerism was detected using a competitive nested polymerase chain reaction for a specific Y chromosome sequence and an internal competitor designed ad hoc. Disease activity and organ involvement were also evaluated.

RESULTS

Sixty samples from 22 patients with SLE and 24 healthy controls were examined. Microchimerism was seen in 11 (50%) patients and 12 (50%) controls. The mean number of male equivalent cells was 2.4 cells/100 000 (range 0.1-17) in patients with SLE and 2.5 (range 0.2-1.8) in healthy controls. No differences in the incidence of microchimerism or in the number of microchimeric cells were found between patients and healthy controls. Patients with a history of lupus nephritis had a higher mean number of fetal cells than patients with no such history. Disease activity did not appear to correlate with microchimerism.

CONCLUSIONS

The preliminary data suggest that microchimerism does not interfere with the disease course of SLE, although further analysis on larger groups will be necessary to confirm these observations.

Identification of a novel HLA-DPB1 allele, DPB1*02014, by sequence-based typing

In this report we describe the identification of a novel DPB1 allele, DPB1*02014, found in an Italian Caucasian individual. The new allele was detected during routine HLA sequence-based typing (SBT) for an individual undergoing bone marrow transplantation. DPB1*02014 was identical to DPB1*02012 except for a single nucleotide substitution in codon 72 (GTG-->GTT). This nucleotide change represents a synonimous mutation, as both triplets code for a valine. This new allele has been submitted to GenBank and assigned the accession number AF326565. The WHO Nomenclature Committee has officially assigned the name DPB1*02014.

[Hemoptysis from dorsal tongue base varices secondary to portal hypertension]

Portal hypertension secondary to cirrhosis of the liver is the main factor leading to the formation of portosystemic collaterals. The sites of such collateral circulation are well known. We describe a case of haemoptysis from dorsal tongue base varices, which are not recognised as portosystemic anastomosis, in a cirrhotic patient with portal hypertension.

[Mycobacterium avium complex in water buffaloes slaughtered for consumption]

Two mycobacterium strains isolated from lung tissue a apical lymph nodes of slaughtered water buffaloes were biochemically analyzed and identified as Mycobacterium avium complex strains. Association between these microorganisms and the acquired immunodeficiency syndrome, and the potential risk posed by eating infected animals and their products, was discussed.

Single-strand conformation polymorphism analysis by capillary zone electrophoresis in neutral pH buffer

Sensitivity of single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products was reported to be lower in capillary zone electrophoresis (CZE) compared to conventional slab gel electrophoresis. We examined the effects of buffer ion type, pH, and temperature in an attempt to improve the mutation detectability in the SSCP-CZE mode. It was noted that, by utilizing short-chain polyacrylamide as sieving media while simultaneously lowering the temperature, there was no improvement of conformer detectability. On the contrary, there was a large increment in conformers' resolution by running samples in a lower-pH buffer system. The effects of different buffering ions and pH values were investigated. By using a new buffer system, consisting of 35 mM 2-(N-morpholino)propanesulfonic acid (MES), 30 mM tris(hydroxymethyl)aminomethane (Tris), 1 mM ethylene diaminetetraacetic acid (EDTA), pH 6.8, and keeping constant all the other conditions, such as temperature, sieving, applied voltage, capillary length, and inner diameter (ID), there was a remarkable improvement in resolution and the sensitivity became comparable to that of slab gel systems.