The Rurality of Lower Extremity Firearm Injuries

BACKGROUND

To highlight the unique spectrum of lower extremity firearm injuries seen at a rural, Midwestern level 1 trauma center to provide insight into prevalence, mechanism of injury, and identify modifiable factors that contribute to firearm injuries of the lower extremity. It is our belief that the creation of our database will help future trauma and firearm databases improve documentation and understand the relationship between anatomic location of injury and outcomes.

METHODS

A retrospective review of lower extremity firearm injuries from a rural, Midwestern level 1 trauma center was collected from January 2011 to December 2019. Data acquired included injury description; demographics, injury mechanism/ description/ location, firearm used, toxicology, and information regarding hospitalization. Data was analyzed using Chi-squared analysis and Fisher's exact test for categorical data and the Wilcoxon rank sum test for continuous data.

RESULTS

69 patients with lower extremity firearm injuries were identified. Average age was 30.14 years, 89.86% were males, and one fatality were identified. 47.83% (33) of these injuries were assaults, followed by unintentional injuries at 42.03% (29). Law enforcement-related and self-inflicted injuries contributed minimally. Handguns were the most common type of firearm, used in 72.5% of cases. Nearly 1/3 of the unintentional firearm injuries occurred during November or December, the active deer hunting months in the community of study.

CONCLUSION

The lower extremity is uniquely vulnerable to both assaults and unintentional injury in our rural environment, differing from what we have previously published regarding the upper extremity. Lower extremity gunshot wounds increased during the winter months, offering a correlation to deer hunting season. Our findings display that not all firearm injuries are created equal, and that there is a need to improve documentation of and additional study in order to optimally tailor firearm prevention measures based on the ruralityurbanicity spectrum. Level of Evidence: III.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Diurnal variation of steroid hormones and their reference intervals using mass spectrometric analysis

OBJECTIVE

Accurate measurement of steroid hormones remains challenging. Mass spectrometry affords a reliable means for quantitating steroid profiles accurately. Our objective was to establish and define (1) the extent of diurnal fluctuations in steroid concentrations that potentially necessitate strict adherence to time of sample acquisition and (2) time-dependent steroid reference intervals.

DESIGN

Nine steroid markers were examined in couplets in males and females.

METHODS

Using isotope dilution high-performance liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis, we developed a multi-steroid profile requiring only a minimal volume of serum (0.1 mL). Couplet (AM and PM) measurements of steroid hormones for 120 healthy females (F) and 62 healthy males (M) were obtained. Patients were recruited from several participating centers.

RESULTS

The following diurnal values were noted to be significantly different in both females and males: cortisone, cortisol, corticosterone, 11 deoxycortisol (11 DOC), androstenedione, 17a-hydroxyprogesterone (17 OHP) and dehydroepiandrosterone (DHEA). Testosterone was only found to have significant diurnal variance in males. Progesterone showed no significant difference in AM and PM values for either groups and thus may provide an internal control.

CONCLUSIONS

When diagnosing endocrine disorders, it is imperative to acknowledge the 24-h diurnal variation of the biochemical steroid markers. We highlight the importance of standardization of collection times and appropriate implementation of reference intervals.

PRECIS

We identify diurnal fluctuations in steroid concentrations with time of day and emphasize the importance of adhering to firm time of sample acquisition.

A small molecule inhibitor of XIAP induces apoptosis and synergises with vinorelbine and cisplatin in NSCLC

Background:

Evasion of apoptosis contributes to the pathogenesis of solid tumours including non-small cell lung cancer (NSCLC). Malignant cells resist apoptosis through over-expression of inhibitor of apoptosis proteins (IAPs), such as X-linked IAP (XIAP).

Methods:

A phenylurea-based small molecule inhibitor of XIAP, XIAP antagonist compound (XAC) 1396-11, was investigated preclincally to determine its ability to sensitise to clinically relevant cytotoxics, potentially allowing dose reduction while maintaining therapeutic efficacy.

Results:

XIAP protein expression was detected in six NSCLC cell lines examined. The cytotoxicity of XAC 1396-11 against cultured NSCLC cell lines in vitro was concentration- and time-dependent in both short-term and clonogenic assays. XAC 1396-11-induced apoptosis was confirmed by PARP cleavage and characteristic nuclear morphology. XAC 1396-11 synergised with vinorelbine±cisplatin in H460 and A549 NSCLC cells. The mechanism of synergy was enhanced apoptosis, shown by increased cleavage of caspase-3 and PARP and by the reversal of synergy by a pan-caspase inhibitor. Synergy between XAC 1396-11 and vinorelbine was augmented by optimising drug scheduling with superior effects when XAC 1396-11 was administered before vinorelbine.

Conclusion:

These preclinical data suggest that XIAP inhibition in combination with vinorelbine holds potential as a therapeutic strategy in NSCLC.

Fas promoter polymorphisms: genetic predisposition to sarcoidosis in African-Americans

Apoptosis may perpetuate some forms of inflammation. Of the apoptotic pathway proteins, Fas is particularly overexpressed in sarcoidosis. We hypothesized that Fas promoter single nucleotide polymorphisms (SNPs) contribute to the development and severity of sarcoidosis. Associations of known Fas promoter SNPs (-670, -690 and -1377) and deduced haplotypes with sarcoidosis and sarcoidosis severity were evaluated using matched case-control (n = 656 pairs) and case-comparison (n = 656) studies, respectively, using conditional logistic regression. Hardy-Weinberg equilibrium was confirmed for all three polymorphisms in African-Americans (AA), and for the -670 and -1377 in whites. Genotype and allele frequencies were significantly different between whites and AA. Race-stratified analysis revealed that a common haplotype, -1377G/-690T/-670G, was associated with sarcoidosis [odds ratio (OR) = 1.78, P = 0.05] only in AA. The haplotype -1377G/-690C/-670A was negatively associated with sarcoidosis (OR = 0.39, P = 0.03) only in AA. In conclusion, the consistency of these findings suggests that Fas promoter genetic variants may be related to sarcoidosis disease risk in AA.

Human leukocyte antigen class II associations with systemic sclerosis in South Africans

Human leukocyte antigen class II typing, using polymerase chain reaction-sequence-specific primers, was performed in 52 Black South Africans with systemic sclerosis (SSc) and 112 controls. Increased frequencies of DR2 in the overall SSc group (OR = 2.4), DRB1*0301 in the limited cutaneous SSc (lcSSc) subset (OR = 9.0), and DQB1*0301/4 in the diffuse cutaneous SSc (dcSSc) subset (OR = 9.0) were observed. Pulmonary fibrosis was associated with DRB1*11 and anti-topoisomerase I antibodies were associated with DPB1*1301 and DRB1*15. Patients with anti-fibrillarin antibodies (AFAs) had increased the frequencies of DRB1*1101 allele group (OR = 16) and DQB1*0603/14 (OR = 13.6). These findings provide new serological and immunogenetic data on a previously unreported population. The association of AFAs with class II alleles merits further investigation.

MHC class II, tumour necrosis factor alpha, and lymphotoxin alpha gene haplotype associations with serological subsets of systemic lupus erythematosus

OBJECTIVE

To conduct a case-control study to investigate whether there are independent tumour necrosis factor alpha (TNFalpha) or lymphotoxin alpha (LTalpha) haplotype associations with SLE or with any of the major serological subsets of SLE.

METHODS

157 patients with SLE were genotyped for HLA-DRB1, HLA-DQB1, TNFalpha, and LTalpha alleles by polymerase chain reaction and compared with 245 normal white controls. For TNFalpha, six single nucleotide polymorphisms (SNPs) at positions -1031, -863, -857, -308, -238, and +488 and for LTalpha three SNPs at positions +720, +365, and +249 were studied to assign six TNFalpha haplotypes (TNF1-6) and four LTalpha haplotypes (LTA1-4). All SLE patients had full serological profiles on serial samples.

RESULTS

The most significant association with SLE overall was with HLA-DR3 (p<0.001; odds ratio (OR) = 2.5 (95% confidence interval, 1.6 to 3.8)) and the extended haplotype HLA-DQB1*0201;DRB1*0301;TNF2;LTA2 (p<0.001; OR = 2.3 (1.4 to 3.7)). Associations were strongest in the anti-La positive group (13%) of SLE patients (HLA-DR3, OR = 71 (9 to 539); HLA-DQB1*0201, OR = 35 (5 to 267); TNF2, OR = 10 (2.8 to 36), and LTA2, OR = 4.9 (1.1 to 21)). There was an increase in the HLA-DR2 associated extended haplotype (HLA-DQB1*0602;DRB1*1501;TNF1;LTA1) in patients with anti-Ro in the absence of anti-La (p<0.005; OR = 3.9 (1.5 to 10)). The HLA-DR7 extended haplotype (HLA-DQB1*0303;DRB1*0701/2;TNF5;LTA3) was decreased in SLE overall (p<0.02; OR = 0.2 (0.05 to 0.8)).

CONCLUSIONS

The strongest association in this predominantly white population with SLE was between HLA-DR3 and anti-La, which seemed to account for any associations with TNFalpha alleles on an extended DR3 haplotype.

Clinical response to morphine in cancer patients and genetic variation in candidate genes

Morphine is the analgesic of choice for moderate to severe cancer pain; however, 10-30% of patients do not tolerate morphine. This study evaluated genetic variation in the mu-opioid receptor, betaarrestin2, stat6 and uridine diphosphate-glucuronysltransferase 2B7 (UGT2B7) genes, in patients who responded to morphine vs those who were switched to alternative opioids. We prospectively recruited and genotyped 162 Caucasian patients (117 controls, 39 switchers). Switchers, were more likely to carry the common allele at 1182 G/A, 5864 G/A, 8622T/C and 11143 G/A in the betaarrestin2 gene (P = 0.021, 0.043, 0.013, 0.043, respectively). Switchers had increased carriage of the T allele (-1714 C/T) and a significant difference in the allelic frequency at 9065 C/T (chi(2) = 3.86, P = 0.049) in the stat6 gene. No differences were seen in genotype or allele frequencies of SNPs in the mu-opioid receptor gene or UGT2B7 gene. This study presents novel data suggesting that variation in genes involved in mu-opioid receptor signalling influence clinical response to morphine.

Cytokine Polymorphisms Do Not Influence Acute Rejection in Renal Transplantation Under Tacrolimus-Based Immunosuppression

INTRODUCTION

Acute rejection remains an important cause of graft loss after renal transplantation. It has been suggested that cytokine genotyping may play a predictive role in identifying individuals who are at higher risk of acute rejection with a view to individualizing their immunosuppression. The aim of this study was to investigate any possible associations between acute rejection and certain cytokine polymorphisms.

METHODS

We genotyped 91 cadaveric renal transplant recipients on tacrolimus-based immunosuppression and 84 of their donors. The cytokine polymorphisms studied were the following: tumor necrosis factor (TNF)-alpha-1032 T/C, TNF-alpha-865 C/A, TNF-alpha-859 G/A, interleukin (IL)1-R1-970 C/T, IL-10 haplotype [-1082, -819, -592], and IL-6-174 C/G.

RESULTS

We found no association between any polymorphism and the incidence of acute rejection. This was true for both the recipient and donor population.

CONCLUSION

Cytokine polymorphisms did not influence acute rejection in our study. We conclude that in the modern era of immunosuppression cytokine genotyping is not a significant predictor of acute rejection in renal transplantation.

HLA class-I and class-II allele frequencies and two-locus haplotypes in Melanesians of Vanuatu and New Caledonia

HLA class-I and class-II allele frequencies and two-locus haplotypes were examined in 367 unrelated Melanesians living on the islands of Vanuatu and New Caledonia. Diversity at all HLA class-I and class-II loci was relatively limited. In class-I loci, three HLA-A allelic groups (HLA-A*24, HLA-A*34 and HLA-A*11), seven HLA-B alleles or allelic groups (HLA-B*1506, HLA-B*5602, HLA-B*13, HLA-B*5601, HLA-B*4001, HLA-B*4002 and HLA-B*2704) and four HLA-C alleles or allelic groups (HLA-Cw*04, HLA-Cw*01, HLA-Cw*0702 and HLA-Cw*15) constituted more than 90% of the alleles observed. In the class-II loci, four HLA-DRB1 alleles (HLA-DRB1*15, HLA-DRB1*11, HLA-DRB1*04 and HLA-DRB1*16), three HLA-DRB3-5 alleles (HLA-DRB3*02, HLA-DRB4*01 and HLA-DRB5*01/02) and five HLA-DQB1 alleles (HLA-DQB1*0301, HLA-DQB1*04, HLA-DQB1*05, HLA-DQB1*0601 and HLA-DQB1*0602) constituted over 93, 97 and 98% of the alleles observed, respectively. Homozygosity showed significant departures from expected levels for neutrality based on allele frequency (i.e. excess diversity) at the HLA-B, HLA-Cw, HLA-DQB1 and HLA-DRB3/5 loci on some islands. The locus with the strongest departure from neutrality was HLA-DQB1, homozygosity being significantly lower than expected on all islands except New Caledonia. No consistent pattern was demonstrated for any HLA locus in relation to malaria endemicity.

Association of HLA-DQ5 and HLA-DR1 with sensitization to organic acid anhydrides

BACKGROUND

Organic acid anhydrides are low molecular weight industrial chemicals, able to cause rhinoconjunctivitis and asthma associated with specific IgE against hapten-carrier protein conjugate. Only a proportion of exposed workers develop IgE-associated allergy to acid anhydrides.

OBJECTIVE

We determined whether genetic susceptibility, in particular, HLA Class II alleles may be a risk factor.

METHODS

We undertook HLA typing in 52 cases who had confirmed specific IgE and in 73 referents matched on site, age and duration of acid anhydride exposure identified in cross-sectional studies of workers exposed to hexahydrophthalic (HHPA), methylhexahydrophthalic (MHHPA) and methyltetrahydrophthalic (MTHPA) anhydrides.

RESULTS

The linked alleles DQ5 (odds ratio [OR]=4.3; 95% confidence interval [95% CI]=1.7, 11) and DR1 (OR 3.0; 95% CI 1.2, 11) were more prevalent in cases than in referents. Within DQ5, DQB1(*)0501 was particularly frequent (OR 3.0; 95% CI 1.2, 7.4).

CONCLUSION

DQB1(*)05 gene confers susceptibility to develop specific IgE antibodies against HHPA, MHHPA and a non-significant trend with MTHPA. DQB1(*)0501 is protective for other low molecular chemical sensitizers (isocyanates and plicatic acid) which may indicate varying affinities for the corresponding specific class II molecules.

Bifunctional apoptosis inhibitor (BAR) protects neurons from diverse cell death pathways

The bifunctional apoptosis regulator (BAR) is a multidomain protein that was originally identified as an inhibitor of Bax-induced apoptosis. Immunoblot analysis of normal human tissues demonstrated high BAR expression in the brain, compared to low or absent expression in other organs. Immunohistochemical staining of human adult tissues revealed that the BAR protein is predominantly expressed by neurons in the central nervous system. Immunofluorescence microscopy indicated that BAR localizes mainly to the endoplasmic reticulum (ER) of cells. Overexpression of BAR in CSM 14.1 neuronal cells resulted in significant protection from a broad range of cell death stimuli, including agents that activate apoptotic pathways involving mitochondria, TNF-family death receptors, and ER stress. Downregulation of BAR by antisense oligonucleotides sensitized neuronal cells to induction of apoptosis. Moreover, the search for novel interaction partners of BAR identified several candidate proteins that might contribute to the regulation of neuronal apoptosis (HIP1, Hippi, and Bap31). Taken together, the expression pattern and functional data suggest that the BAR protein is involved in the regulation of neuronal survival.

Skin cancers in renal-transplant recipients occur more frequently than previously recognized in a temperate climate

BACKGROUND

Renal-transplant recipients are at increased risk of developing skin cancers, especially squamous cell carcinoma. We have carried out a comprehensive epidemiologic review of skin cancers occurring in a population receiving transplants in Oxford over a 21-year period, where nearly all patients have remained under the care of the Oxford Transplant Centre.

METHODS

Between 1975 and 1996, 1,360 renal transplants were performed in 1,115 patients. Skin cancer data were reviewed in 979 patients from this group who remained under the care of the Oxford Transplant Centre. The lesions included in the analysis were histologically confirmed basal cell carcinoma, Bowen's disease, squamous cell carcinoma, keratoacanthoma, malignant melanoma, Merkel cell tumor, and sebaceous carcinoma.

RESULTS

One hundred eighty-seven (19.1%) transplant patients developed at least one skin malignancy. The rate of skin cancer was 141 per 1,000 person years at risk. Sixty-four percent of patients with skin cancer had multiple lesions (maximum 50). Squamous cell carcinoma was the most common skin cancer to develop and the most common first skin cancer to present. The mean time to presentation of the first skin cancer was 8 years. Six patients developed nodal metastases, and two patients died secondary to skin cancer. Risk factors identified were increasing age at transplantation, recipient sex, total time of exposure to immunosuppression, increased creatinine levels at 1 year, and graft relation. The cumulative incidence of skin cancer reached 61% at 20 years after transplantation.

CONCLUSION

The data from this study suggest that more patients develop skin malignancies than previously reported from Europe. It is important to advise patients before transplantation in regard to skin complications, provide regular dermatological follow-up, and tailor immunosuppressive regimen to minimum doses to be compatible with good graft function.

Interleukin 1alpha, interleukin 1beta and interleukin 1 receptor gene polymorphisms in psoriatic arthritis

OBJECTIVES

To investigate polymorphisms of interleukin (IL) 1alpha, IL-1beta and IL-1 receptor R1 genes in patients with psoriatic arthritis (PsA), their relationship to the age of onset of psoriasis and the pattern of joint involvement.

METHODS

One hundred and forty well-characterized patients with PsA were studied. One hundred healthy controls were recruited from primary care. All were genotyped for single-nucleotide polymorphisms in the genes for IL-1alpha (position -889), IL-1beta (position +3953) and IL-1R1 (position +970). The frequencies of the respective variants were compared between patients and controls and in relation to age of onset of psoriasis, to clinical subsets of the disease and to the presence of erosions.

RESULTS

All three polymorphisms were in Hardy-Weinberg equilibrium in both patients and controls. The frequency of IL-1alpha -889 CC homozygotes was significantly increased in PsA patients compared with normal controls [58 vs 40%, odds ratio (OR) 2.06, 95%, confidence interval (CI) 1.22-3.47]. The frequency of the IL-1alpha -889 C allele was significantly increased in PsA patients compared with controls (75 vs 65%, OR 1.65, 95% CI 1.11-2.45). In subset analysis there were no other significant differences in allelic frequencies for the IL-1alpha -889 C/T, IL-1beta +3953 C/T and IL-1R1 +970 C/T polymorphisms.

CONCLUSIONS

The IL-1 gene complex may play a role in the development of PsA and/or psoriasis or act as a marker for other genes on chromosome 2q12 to 2q13.

A retrospective study of the association between haematological and biochemical parameters and morphine intolerance in patients with cancer pain

BACKGROUND

Morphine is the strong opioid of choice for the treatment of moderate to severe cancer pain according to guidelines of the World Health Organization (WHO). However, a minority of patients do not receive the desired analgesic effect or suffer intolerable side effects from morphine, and are switched to alternative opioids.

METHODS

The aim of this retrospective study was to identify factors that might be associated with morphine intolerance. Data were analysed from 100 controls who tolerated morphine and 77 patients who were switched to an alternative opioid. We investigated whether currently logged data could fully explain the need to switch. Demographic details, cancer type (histological diagnosis) and markers related to organ function were included in an analysis of biochemical and haematological parameters.

RESULTS

Patients over 78 years (P = 0.03), or with a high white cell (P = 0.002) or high platelet count (P = 0.003), were more likely to switch. Although our numbers were small, patients with severe organ impairment were more likely to switch. However, a model including white cell count, platelet count, age, serum albumin and alkaline phosphatase, accurately separated switchers and controls in only 68% of cases. There was no significant difference between the two groups in terms of the numbers of patients having cytotoxic drugs in the two weeks prior to the haematological and biochemical analysis. Similarly, there were no significant differences in histological diagnoses between groups.

CONCLUSIONS

The white cell count was the strongest single effect observed and, as such, warrants further investigation. Further studies are needed in order to accurately define a model that will predict those patients likely to be intolerant of morphine.

Tumour necrosis factor-alpha polymorphism and the HLA-Cw*0602 allele in psoriatic arthritis

OBJECTIVES

To investigate polymorphisms in the genes for tumour necrosis factor alpha (TNFA), interleukin 10 (IL10) and tumour necrosis factor receptor II (TNFRII) in patients with psoriatic arthritis (PsA) and their relationship to the HLA-Cw*0602 allele and to the ages at onset of psoriasis and arthritis and the pattern of joint involvement.

METHODS

One hundred and twenty-four well-characterized patients with PsA were studied. Controls were 101 cadaveric organ donors. All were genotyped for single-nucleotide polymorphisms in TNFA (positions -308, -238, +488), IL10 (-1082, -819, -592) and in the 3'-untranslated region of TNFRII (+1663, +1668, +1690). The HLA-Cw*0602 allele was detected by polymerase chain reaction-based techniques. The frequencies of the respective variants were compared between patients and controls and in relation to the ages at onset of psoriasis and arthritis, to clinical subsets of the disease and to the presence of erosions.

RESULTS

HLA-Cw*0602 was significantly increased in frequency in PsA (40 vs 26%; P<0.05) and was associated with younger age of onset of psoriasis (P<0.05). There was no significant increase in any of the polymorphisms studied within TNFA, IL10 or TNFRII in the total PsA group. Although the frequency of TNFA allele -238A was not increased in the total PsA group or in patients with a younger age of onset of psoriasis, TNFA allele -238A was absent in the spondyloarthritis group and increased in frequency in patients with peripheral polyarthritis. However, these latter findings could be explained by linkage disequilibrium as all TNFA -238A alleles (23/23) in patients with PsA were HLA-Cw*0602-positive (P<0.0001).

CONCLUSIONS

An association between young age of onset of psoriasis and HLA-Cw*0602 is confirmed in patients with PsA. The uncommon TNFA -238A allele is strongly linked to HLA-Cw*0602 and as such is associated with the development of peripheral polyarthritis rather than spondylitis. Further investigation of possible HLA-Cw*0602 linked genes in PsA is warranted.

Immune responses to native beta(2)-glycoprotein I in patients with systemic lupus erythematosus and the antiphospholipid syndrome

OBJECTIVE

To identify HLA class II associations with anti beta(2)-glycoprotein I (beta2GPI) antibodies in a cohort of Caucasian patients with systemic lupus erythematosus (SLE) and to determine whether these HLA genotypes act as restriction elements for lymphocyte proliferation to native human beta2GPI in vitro.

METHODS

Anti-beta2GPI antibodies were detected in patient sera using enzyme-linked immunosorbent assays (ELISAs). HLA class II alleles (DRB1, DQB1) were determined by polymerase chain reaction-based DNA genotyping. In vitro peripheral blood mononuclear cell (PBMC) responses to native human beta2GPI were measured in a 7-day proliferation assay.

RESULTS

We identified three groups of Caucasian SLE patients using these ELISAs. In group 1, 16 out of 18 SLE patients (89%) with anti-beta2GPI antibodies were positive for HLA-DRB1*0401/4/8, DR11 or DRB1*1302 (P=0.001 vs controls) compared with 23 out of 53 patients (43%) in group 2 with anti-cardiolipin antibodies only, 57 out of 151 patients (38%) in group 3 (SLE patients without anticardiolipin antibodies) and 109 out of 225 controls (48%). Fourteen patients with anti-beta2GPI antibodies had greater median stimulation indices to beta2GPI in vitro compared with the 15 controls studied (P=0.04).

CONCLUSION

The HLA class II and PBMC proliferation data suggest that beta2GPI may be both a T- and B-cell autoantigen in SLE.

The study of CTLA-4 and vitamin D receptor polymorphisms in the Romanian type 1 diabetes population

Several studies suggested that part of the genetic susceptibility for Type 1 diabetes (T1DM) is encoded by some polymorphisms of CTLA-4 gene (2q33) and of Vitamin D Receptor gene (VDR; 12q12-14). Our aim was to assess their contribution to T1DM genetic susceptibility in the Romanian population. We typed CTLA-4 49 A/G and VDR FokI (F/f), ApaI (A/a) and TaqI (T/t) polymorphisms by Sequence Specific Primer PCR (SSP-PCR) in 204 Romanian diabetic families (756 individuals: 212 T1DM probands and 544 unaffected parents and siblings). We studied alleles transmission using the Transmission Disequilibrium Test (TDT). We found an increased transmission of CTLA-4 49G allele to diabetics (54.8%, p=0.11). The transmission of F (56.1%, p=0.063), a (55.7%, p=0.061) and T (51.8%, p=0.37) alleles of VDR gene to diabetics was increased but did not reach statistical significance. In conclusion we found the same increased transmission of CTLA-4 49 G allele to diabetics as previously reported. VDR FoqI F allele seems to be predisposing while TaqI T allele seems to be protective.

Low frequency of HLA DRB1*03 - DQB1*02 and DQB1*0302 haplotypes in Romania is consistent with the country's low incidence of Type I diabetes

AIMS/HYPOTHESIS

Our study aimed to determine the association of HLA class II HLA-DQB1 alleles with Type I (insulin-dependent) diabetes mellitus and the frequencies of these alleles in the Romanian population, which has one of the lowest incidences of Type I diabetes in children aged 0-14 years in Europe at 3-4 cases per 100,000 person-years.

METHODS

We used the sequence specific primer-polymerase chain reaction (PCR-SSP) technique to type HLA-DQB1 alleles, the HLA-DRB1alleles DRB1*03 and one single nucleotide polymorphism (SNP) in the insulin gene (INS). We studied 204 Type I diabetic Romanian families, 196 of which were simplex with 70.3 % of subjects diagnosed under 14 years of age. Data was analysed using a modified version of the Transmission Disequilibrium Test, the Transmission Disequilibrium Test itself, and the affected family-based control method.

RESULTS

We found, as expected, the strong positive DQB1*02-DRB1*03 and DQB1*0302, and negative DQB1*0602, HLA class II allele associations with Type I diabetes in these Romanian families. However, using the affected family-based control method, we found relatively low population frequencies of DQB1*02-DRB1*03 and DQB1*0302 alleles in Romania (15.8%) compared with Sardinia (31.3%), a high incidence European region (35 cases per 100,000 person-years in children aged 0-14years). The INS locus had a strong effect in this data set with 80.5 % transmission of the susceptible INS allele from parents to affected siblings (relative risk = 4.1).

CONCLUSION/INTERPRETATION

Part of the explanation for the low incidence of Type I diabetes in Romania could be the lower frequency of the DRB1*03 DQB1*02 and DQBI*0302 susceptibility haplotypes in this country.

TUCAN, an antiapoptotic caspase-associated recruitment domain family protein overexpressed in cancer

Caspase-associated recruitment domains (CARDs) are protein interaction domains that participate in activation or suppression of CARD-carrying members of the caspase family of apoptosis-inducing proteases. A novel CARD-containing protein was identified that is overexpressed in some types of cancer and that binds and suppresses activation of procaspase-9, which we term TUCAN (tumor-up-regulated CARD-containing antagonist of caspase nine). The CARD domain of TUCAN selectively binds itself and procaspase-9. TUCAN interferes with binding of Apaf1 to procaspase-9 and suppresses caspase activation induced by the Apaf1 activator, cytochrome c. Overexpression of TUCAN in cells by stable or transient transfection inhibits apoptosis and caspase activation induced by Apaf1/caspase-9-dependent stimuli, including Bax, VP16, and staurosporine, but not by Apaf1/caspase-9-independent stimuli, Fas and granzyme B. High levels of endogenous TUCAN protein were detected in several tumor cell lines and in colon cancer specimens, correlating with shorter patient survival. Thus, TUCAN represents a new member of the CARD family that selectively suppresses apoptosis induced via the mitochondrial pathway for caspase activation.

The use of an inexpensive red acetate filter to improve the sensitivity of GAFChromic dosimetry

The sensitivity of GAFChromic dosimetry using a conventional broad band light source densitometer has significantly been improved twofold using an inexpensive red acetate filter overlay during the densitometric measurements. This thin sheet of red acetate enhances the dosimetric analysis of radiochromic blue image distributions recorded on GAFChromic films. The combination provides higher sensitivity in the optical density measurements than the more expensive He-Ne laser-scanning densitometers.

The HLA-DPB1--associated component of the IDDM1 and its relationship to the major loci HLA-DQB1, -DQA1, and -DRB1

The major histocompatibility complex (MHC) HLA region on chromosome 6p21 contains the major locus of type 1 diabetes (IDDM1). Common allelic variants at the class II HLA-DRB1, -DQA1, and -DQB1 loci account for the major part of IDDM1. Previous studies suggested that other MHC loci are likely to contribute to IDDM1, but determination of their relative contributions and identities is difficult because of strong linkage disequilibrium between MHC loci. One prime candidate is the polymorphic HLA-DPB1 locus, which (with the DPA1 locus) encodes the third class II antigen-presenting molecule. However, the results obtained in previous studies appear to be contradictory. Therefore, we have analyzed 408 white European families (200 from Sardinia and 208 from the U.K.) using a combination of association tests designed to directly compare the effect of DPB1 variation on the relative predisposition of DR-DQ haplotypes, taking into account linkage disequilibrium between DPB1 and the DRB1, DQA1, and DQB1 loci. In these populations, the overall contribution of DPB1 to IDDM1 is small. The main component of the DPB1 contribution to IDDM1 in these populations appears to be the protection associated with DPB1*0402 on DR4-negative haplotypes. We suggest that the HLA-DP molecule itself contributes to IDDM1.

A novel enhancer of the Apaf1 apoptosome involved in cytochrome c-dependent caspase activation and apoptosis

Apaf1/CED4 family members play central roles in apoptosis regulation as activators of caspase family cell death proteases. These proteins contain a nucleotide-binding (NB) self-oligomerization domain and a caspase recruitment domain (CARD). A novel human protein was identified, NAC, that contains an NB domain and CARD. The CARD of NAC interacts selectively with the CARD domain of Apaf1, a caspase-activating protein that couples mitochondria-released cytochrome c (cyt-c) to activation of cytosolic caspases. Cyt-c-mediated activation of caspases in cytosolic extracts and in cells is enhanced by overexpressing NAC and inhibited by reducing NAC using antisense/DNAzymes. Furthermore, association of NAC with Apaf1 is cyt c-inducible, resulting in a mega-complex (>1 MDa) containing both NAC and Apaf1 and correlating with enhanced recruitment and proteolytic processing of pro-caspase-9. NAC also collaborates with Apaf1 in inducing caspase activation and apoptosis in intact cells, whereas fragments of NAC representing only the CARD or NB domain suppress Apaf1-dependent apoptosis induction. NAC expression in vivo is associated with terminal differentiation of short lived cells in epithelia and some other tissues. The ability of NAC to enhance Apaf1-apoptosome function reveals a novel paradigm for apoptosis regulation.

TRAF1 is a substrate of caspases activated during tumor necrosis factor receptor-alpha-induced apoptosis

TRAF family proteins are signal-transducing adapter proteins that interact with the cytosolic domains of tumor necrosis factor (TNF) family receptors. Here we show that TRAF1 (but not TRAF2-6) is cleaved by certain caspases in vitro and during TNF-alpha- and Fas-induced apoptosis in vivo. (160)LEVD(163) was identified as the caspase cleavage site within TRAF1, generating two distinct fragments. Significant enhancement of TNF receptor-1 (CD120a)- and, to a lesser extent, Fas (CD95)-mediated apoptosis was observed when overexpressing the C-terminal TRAF1 fragment in HEK293T and HT1080 cells. The same fragment was capable of potently suppressing TNF receptor-1- and TRAF2-mediated nuclear factor-kappaB activation in reporter gene assays, providing a potential mechanism for the enhancement of TNF-mediated apoptosis. Cell death induced by other death receptor-independent stimuli such as cisplatin, staurosporine, and UV irradiation did not result in cleavage of TRAF1, and overexpression of the C-terminal TRAF1 fragment did not enhance cell death in these cases. TRAF1 cleavage was markedly reduced in cells that contain little procaspase-8 protein, suggesting that this apical protease in the TNF/Fas death receptor pathway is largely responsible. These data identify TRAF1 as a specific target of caspases activated during TNF- and Fas-induced apoptosis and illustrate differences in the repertoire of protease substrates cleaved during activation of different apoptotic pathways.

TNFR-associated factor family protein expression in normal tissues and lymphoid malignancies

TNFR-associated factors (TRAFs) constitute a family of adapter proteins that associate with particular TNF family receptors. Humans and mice contain six TRAF genes, but little is known about their in vivo expression at the single cell level. The in vivo locations of TRAF1, TRAF2, TRAF5, and TRAF6 were determined in human and mouse tissues by immunohistochemistry. Striking diversity was observed in the patterns of immunostaining obtained for each TRAF family protein, suggesting their expression is independently regulated in a cell type-specific manner. Dynamic regulation of TRAFs was observed in cultured PBLs, where anti-CD3 Abs, mitogenic lectins, and ILs induced marked increases in the steady-state levels of TRAF1, TRAF2, TRAF5, and TRAF6. TRAF1 was also highly inducible by CD40 ligand in cultured germinal center B cells, whereas TRAF2, TRAF3, TRAF5, and TRAF6 were relatively unchanged. Analysis of 83 established human tumor cell lines by semiquantitative immunoblotting methods revealed tendencies of certain cancer types to express particular TRAFs. For example, expression of TRAF1 was highly restricted, with B cell lymphomas consistently expressing this TRAF family member. Consistent with results from tumor cell lines, immunohistochemical analysis of 232 non-Hodgkin lymphomas revealed TRAF1 overexpression in 112 (48%) cases. TRAF1 protein levels were also elevated in circulating B cell chronic lymphocytic leukemia specimens (n = 49) compared with normal peripheral blood B cells (p = 0.01), as determined by immunoblotting. These findings contribute to an improved understanding of the cell-specific roles of TRAFs in normal tissues and provide evidence of altered TRAF1 expression in lymphoid malignancies.

Molecular basis for CD40 signaling mediated by TRAF3

Tumor necrosis factor receptors (TNFR) are single transmembrane-spanning glycoproteins that bind cytokines and trigger multiple signal transduction pathways. Many of these TNFRs rely on interactions with TRAF proteins that bind to the intracellular domain of the receptors. CD40 is a member of the TNFR family that binds to several different TRAF proteins. We have determined the crystal structure of a 20-residue fragment from the cytoplasmic domain of CD40 in complex with the TRAF domain of TRAF3. The CD40 fragment binds as a hairpin loop across the surface of the TRAF domain. Residues shown by mutagenesis and deletion analysis to be critical for TRAF3 binding are involved either in direct contact with TRAF3 or in intramolecular interactions that stabilize the hairpin. Comparison of the interactions of CD40 with TRAF3 vs. TRAF2 suggests that CD40 may assume different conformations when bound to different TRAF family members. This molecular adaptation may influence binding affinity and specific cellular triggers.

Distribution of novel polymorphisms of the interleukin-8 and CXC receptor 1 and 2 genes in systemic sclerosis and cryptogenic fibrosing alveolitis

OBJECTIVE

To search for single-nucleotide polymorphisms in the interleukin-8 (IL-8) and IL-8 receptor CXCR-1 and CXCR-2 genes, and to compare their distribution among patients with systemic sclerosis (SSc) with fibrosing alveolitis (FASSc) or without fibrosing alveolitis (NFASSc), or patients with cryptogenic fibrosing alveolitis (CFA), and normal healthy subjects.

METHODS

Fifty control subjects were screened for potential polymorphisms by using polymerase chain reaction in association with sequence-specific primers incorporating mismatches at the 3' end. The novel polymorphisms were subsequently examined in British Caucasian subjects, including 194 healthy controls, 71 patients with CFA, and 128 patients with SSc who were further subdivided into 78 FASSc patients and 50 NFASSc patients.

RESULTS

Three novel biallelic polymorphisms were identified in the IL-8 gene (all in noncoding areas of the gene), 1 was found in the CXCR-1 gene (resulting in a conservative amino acid change), and 3 were observed in the CXCR-2 gene, of which the first resulted in a silent codon change and the others were in the 3' untranslated area of exon 3. Compared with controls, a significant increase in the frequency of the CXCR-2 +785 CC homozygote and of the CXCR-2 +1208 TT homozygote was found in the SSc patients (37% versus 22% [P = 0.01] and 33% versus 17% [P = 0.003], respectively). A subgroup analysis revealed this association to be significant both in the FASSc patients and in the NFASSc patients.

CONCLUSION

This report describes an association between SSc and 2 polymorphisms occurring close to each other in the CXCR-2 gene. This finding and its functional significance need to be confirmed and analyzed in future studies.

A two-stage, genome-wide screen for susceptibility loci in primary Raynaud's phenomenon

OBJECTIVE

To identify chromosomal regions containing genes involved in the susceptibility to primary Raynaud's phenomenon (RP).

METHODS

Six extended families with multiple individuals affected with primary RP (n = 37) were examined for linkage in a 2-stage, whole-genome screen, using a total of 298 microsatellite markers.

RESULTS

Multipoint, nonparametric linkage analysis identified 5 areas of possible linkage, with a nominal level of significance of P < or = 0.05. Analysis of a finer map of markers in these regions defined the regions of linkage as 21.4 cM on 6q13-6q23.3 (D6S261; P = 0.0004), 10.2 cM on 7p22-7p15 (D7S664; P = 0.014), 1.6 cM on 9p23-9p22 (D9S156; P = 0.0075), 5.1 cM on 17p13.1-17p12 (D17S1791; P = 0.036), and 11.8 cM on Xp11.4-Xp11.23 (DXS8054; P = 0.006). Three potential candidate genes map to these regions: the beta subunit of the muscle acetylcholine receptor and the serotonin 1B and 1E receptors.

CONCLUSION

These results provide evidence of the presence and location of genes that are involved in the genetic susceptibility to primary RP.

Distribution of novel polymorphisms of the interleukin-8 and CXC receptor 1 and 2 genes in systemic sclerosis and cryptogenic fibrosing alveolitis

OBJECTIVE

To search for single-nucleotide polymorphisms in the interleukin-8 (IL-8) and IL-8 receptor CXCR-1 and CXCR-2 genes, and to compare their distribution among patients with systemic sclerosis (SSc) with fibrosing alveolitis (FASSc) or without fibrosing alveolitis (NFASSc), or patients with cryptogenic fibrosing alveolitis (CFA), and normal healthy subjects.

METHODS

Fifty control subjects were screened for potential polymorphisms by using polymerase chain reaction in association with sequence-specific primers incorporating mismatches at the 3' end. The novel polymorphisms were subsequently examined in British Caucasian subjects, including 194 healthy controls, 71 patients with CFA, and 128 patients with SSc who were further subdivided into 78 FASSc patients and 50 NFASSc patients.

RESULTS

Three novel biallelic polymorphisms were identified in the IL-8 gene (all in noncoding areas of the gene), 1 was found in the CXCR-1 gene (resulting in a conservative amino acid change), and 3 were observed in the CXCR-2 gene, of which the first resulted in a silent codon change and the others were in the 3' untranslated area of exon 3. Compared with controls, a significant increase in the frequency of the CXCR-2 +785 CC homozygote and of the CXCR-2 +1208 TT homozygote was found in the SSc patients (37% versus 22% [P = 0.01] and 33% versus 17% [P = 0.003], respectively). A subgroup analysis revealed this association to be significant both in the FASSc patients and in the NFASSc patients.

CONCLUSION

This report describes an association between SSc and 2 polymorphisms occurring close to each other in the CXCR-2 gene. This finding and its functional significance need to be confirmed and analyzed in future studies.

Expression and prognostic significance of IAP-family genes in human cancers and myeloid leukemias

Expression of several inhibitor of apoptosis proteins (IAPs) was investigated in the National Cancer Institute panel of 60 human tumor cell lines, and the expression and prognostic significance of one of these, XIAP, was evaluated in 78 previously untreated patients with acute myelogenous leukemia (AML). XIAP and cIAP1 were expressed in most cancer lines analyzed, with substantial variability in their relative levels. In contrast, NAIP mRNA was not detectable, and cIAP2 was found at the mRNA and protein levels in only 34 (56%) and 5 (8%) of the 60 tumor cell lines analyzed, respectively. Interestingly, XIAP, cIAP1, and cIAP2 mRNA levels did not correlate with protein levels in the tumor lines, indicating posttranscriptional regulation of expression. High levels of XIAP protein in tumor cell lines were unexpectedly correlated with sensitivity to some anticancer drugs, particularly cytarabine and other nucleosides, whereas higher levels of cIAP1 protein levels were associated with resistance to several anticancer drugs. The relevance of XIAP to in vivo responses to cytarabine was explored in AML, making correlations with patient outcome (n = 78). Patients with lower levels of XIAP protein had significantly longer survival (median, 133 versus 52.5 weeks; P = 0.05) and a tendency toward longer remission duration (median, 87 versus 52.5 weeks; P = 0.13) than those with higher levels of XIAP. Altogether, these findings show that IAPs are widely but differentially expressed in human cancers and leukemias and suggest that higher XIAP protein levels may have adverse prognostic significance for patients with AML.

Lichen sclerosus premenarche: autoimmunity and immunogenetics

Lichen sclerosus is among the most frequently seen paediatric vulval disorders. In adults a strong association between lichen sclerosus and autoimmune diseases, and also with HLA class II locus DQ7, has been well demonstrated in women and a weaker association in men. These associations have not previously been studied in children, although in other autoimmune diseases, the HLA associations have been strongest in children. We performed HLA tissue typing and looked for autoimmune associations in a group of 30 children with vulval lichen sclerosus. HLA DQ7 was present in 66% of female children with lichen sclerosus compared with 31% in controls. Previous studies reported DQ7 in 51% of adult female patients and 45% of male patients. Sixteen per cent of the children were homozygous for DQ7 as opposed to 5% of controls. In the childhood group, only 4% had another autoimmune disease, but 56% of their parents or grandparents did. Age differences make comparison difficult, but the family history of autoimmunity appears to be strong in the early-onset group, in addition to the stronger association with DQ7.

Adult linear IgA disease and chronic bullous disease of childhood: the association with human lymphocyte antigens Cw7, B8, DR3 and tumour necrosis factor influences disease expression

Linear IgA disease and chronic bullous disease of childhood are both subepidermal autoimmune blistering diseases. Class I and II major histocompatibility locus (MHC) antigen typing was performed on 60 patients (26 chronic bullous disease of childhood, 34 adult linear IgA disease), and the findings were correlated with the clinical course. The typing was performed using a lymphocyte microcytotoxicity assay, and the results were compared with a reference population of U.K. organ donors. Analysis of the tumour necrosis factor (TNF) locus was performed using sequence-specific oligonucleotides on a dot blot in 51 patients and compared with a random control population and human lymphocyte antigen (HLA) DR3 matched controls. The disease was found to be significantly associated with HLA Cw7 (chi2 = 19.24, P = 0.001), B8 (chi2 = 9.89, P = 0.04) and DR3 (chi2 = 10.47, P = 0.014), all components of the common Caucasian haplotype. There was also a close association between the disease and possession of HLA DR2 or 3 (chi2 = 16.34, P = 0.001). A reduction in the incidence of DR1 and DR4 (alleles carrying the rheumatoid motif) was observed, which is more marked in the children (chi2 = 8.34, P = 0.039). In the childhood group there was an increased frequency of B8, DR3 and DQ2 compared with the adults which included five of 26 who were homozygous for these antigens, a feature not seen in the adults, which may account for the differences seen between the two groups. Possession of HLA B8, DR3 and DQ2 probably facilitates earlier presentation of the disease as there is no evidence from our results that the adults and children differ fundamentally in their MHC associations. The rare TNF2 allele was found in 29 of 51 patients (expected 8.2, chi2 = 18. 3, P = 0.0001). This was more marked in the children (19 of 26). Patients with the TNF2 allele had a longer disease duration (5.3 years TNF2, 3.0 years TNF1).

Cleavage of human inhibitor of apoptosis protein XIAP results in fragments with distinct specificities for caspases

Several human inhibitor of apoptosis (IAP) family proteins function by directly inhibiting specific caspases in a mechanism that does not require IAP cleavage. In this study, however, we demonstrate that endogenous XIAP is cleaved into two fragments during apoptosis induced by the tumor necrosis factor family member Fas (CD95). The two fragments produced comprise the baculoviral inhibitory repeat (BIR) 1 and 2 domains (BIR1-2) and the BIR3 and RING (BIR3-Ring) domains of XIAP. Overexpression of the BIR1-2 fragment inhibits Fas-induced apoptosis, albeit at significantly reduced efficiency compared with full-length XIAP. In contrast, overexpression of the BIR3-Ring fragment results in a slight enhancement of Fas-directed apoptosis. Thus, cleavage of XIAP may be one mechanism by which cell death programs circumvent the anti-apoptotic barrier posed by XIAP. Interestingly, ectopic expression of the BIR3-Ring fragment resulted in nearly complete protection from Bax-induced apoptosis. Use of purified recombinant proteins revealed that BIR3-Ring is a specific inhibitor of caspase-9 whereas BIR1-2 is specific for caspases 3 and 7. Therefore XIAP possesses two different caspase inhibitory activities which can be attributed to distinct domains within XIAP. These data may provide an explanation for why IAPs have evolved with multiple BIR domains.

An evaluation of the Banff classification of early renal allograft biopsies and correlation with outcome

BACKGROUND

The Banff classification for assessment of renal allograft biopsies was introduced as a standardized international classification of renal allograft pathology and acute rejection. Subsequent debate and evaluation studies have attempted to develop and refine the classification. A recent alternative classification, known as the National Institutes of Health Collaborative Clinical Trials in Transplantation (NIH-CCTT) classification, proposed three distinct types of acute rejection. The 1997 Fourth Banff meeting appeared to move towards a consensus for describing transplant biopsies, which incorporated both approaches. Patients who received a renal allograft at the Oxford Transplant Centre were managed by a combination of protocol and clinically indicated biopsies. We have undertaken a retrospective analysis of the biopsies correlated with the clinical outcome to test the prognostic value of the original Banff (Banff 93-95) and NIH-CCTT classifications.

METHODS

Three hundred and eighty-two patients received renal allografts between May 1985 and December 1989, and were immunosuppressed using a standard protocol of cyclosporine, azathioprine and steroid. Adequate 5-year follow-up data were available on 351 patients, and of these, 293 had at least one satisfactory biopsy taken between days 2 and 35 after transplantation, the latter patients forming the study group. The D2-35 biopsies taken from these patients, which were not originally reported according to the Banff classification, were re-examined and classified according to the Banff 93-95 protocols. For each patient the biopsy found to be the most severely abnormal was selected, and the Banff and NIH-CCTT grading compared with the clinical outcome.

RESULTS

Seven hundred and forty-three biopsies taken from 293 patients between days 2 and 35 after transplantation were examined and the patients categorized on the basis of the 'worst' Banff grading as follows. Normal or non-rejection, 20%; borderline, 34%; acute rejection grade I (AR I), 18%; AR IIA, 6%; AR IIB, 14%; AR III, 1%; AR IIIC, 3%; widespread necrosis 3%. The clinical outcome for the last two groups combined was very poor with 18% of grafts functioning at 3 months and 6% at 5 years. The other groups with vascular rejection (AR IIB and AR III) had an intermediate outcome, graft survival being 78% at 3 months and 61% at 5 years. The remaining four groups (normal, borderline, cellular AR I and AR IIA) had the best outcome: graft survival 95% at 3 months and 78% at 5 years with virtually no difference between the four groups. Three forms of acute rejection, namely tubulo-interstitial, vascular and transmural vascular, were identified, but only the latter two categories were associated with a poor outcome.

CONCLUSIONS

The eight sub-categories of the Banff classification of renal allograft biopsies are associated with three different prognoses with respect to graft survival in the medium term. These three prognostic groups correspond to the three NIH-CCTT types. The data provide support for the consensus developed at Banff 97 separating tubulo-interstitial, vascular and transmural vascular rejection (types I, II and III acute rejection).

A susceptibility region for myasthenia gravis extending into the HLA-class I sector telomeric to HLA-C

We have analyzed a series of HLA region markers in 207 UK Caucasoids with early-onset myasthenia gravis (EOMG, onset before age 40), where there is a strong female bias. The well known associations with HLA-DR3 and -B8 have now proved to be significantly stronger in the 165 females than in the 42 males. In patients (of either sex) lacking -DR3, there was also a significant increase in HLA-DR2. Although the muscle weakness in EOMG is clearly mediated by autoantibodies, the associations are consistently stronger with HLA-B8 (in class I) than with HLADR3 (in class II), as confirmed here. We therefore typed 87-137 cases for polymorphisms at four loci in the intervening class III region, and also at three in the adjacent stretch of class I. At each locus, one allele tended to co-occur with HLA-B8 and showed strong and highly significant associations in the patients. There appeared to be a region of maximal susceptibility extending from HSP70 (in class III) past HLA-B and HLA-C at least 600 kb telomerically into the class I region, which is now being mapped in detail. Any candidate genes here that act shortly after puberty may allow more precise localization of susceptibility.

Differential requirements for tumor necrosis factor receptor-associated factor family proteins in CD40-mediated induction of NF-kappaB and Jun N-terminal kinase activation

CD40 is a member of the tumor necrosis factor receptor family that mediates a number of important signaling events in B-lymphocytes and some other types of cells through interaction of its cytoplasmic (ct) domain with tumor necrosis factor receptor-associated factor (TRAF) proteins. Alanine substitution and truncation mutants of the human CD40ct domain were generated, revealing residues critical for binding TRAF2, TRAF3, or both of these proteins. In contrast to TRAF2 and TRAF3, direct binding of TRAF1, TRAF4, TRAF5, or TRAF6 to CD40 was not detected. However, TRAF5 could be recruited to wild-type CD40 in a TRAF3-dependent manner but not to a CD40 mutant (Q263A) that selectively fails to bind TRAF3. CD40 mutants with impaired binding to TRAF2, TRAF3, or both of these proteins completely retained the ability to activate NF-kappaB and Jun N-terminal kinase (JNK), implying that CD40 can stimulate TRAF2- and TRAF3-independent pathways for NF-kappaB and JNK activation. A carboxyl-truncation mutant of CD40 lacking the last 32 amino acids required for TRAF2 and TRAF3 binding, CD40(Delta32), mediated NF-kappaB induction through a mechanism that was suppressible by co-expression of TRAF6(DeltaN), a dominant-negative version of TRAF6, but not by TRAF2(DeltaN), implying that while TRAF6 does not directly bind CD40, it can participate in CD40 signaling. In contrast, TRAF6(DeltaN) did not impair JNK activation by CD40(Delta32). Taken together, these findings reveal redundancy in the involvement of TRAF family proteins in CD40-mediated NF-kappaB induction and suggest that the membrane-proximal region of CD40 may stimulate the JNK pathway through a TRAF-independent mechanism.

Release of caspase-9 from mitochondria during neuronal apoptosis and cerebral ischemia

Caspase-9 is critical for cytochrome c (cyto-c)-dependent apoptosis and normal brain development. We determined that this apical protease in the cyto-c pathway for apoptosis resides inside mitochondria in several types of cells, including cardiomyocytes and many neurons. Caspase-9 is released from isolated mitochondria on treatment with Ca2+ or Bax, stimuli implicated in ischemic neuronal cell death that are known to induce cyto-c release from mitochondria. In neuronal cell culture models, apoptosis-inducing agents trigger translocation of caspase-9 from mitochondria to the nucleus, which is inhibitable by Bcl-2. Similarly, in an animal model of transient global cerebral ischemia, caspase-9 release from mitochondria and accumulation in nuclei was observed in hippocampal and other vulnerable neurons exhibiting early postischemic changes preceding apoptosis. Loss of mitochondrial barrier function during neuronal damage from ischemia or other insults therefore may play an important role in making certain caspases available to participate in apoptosis.

Molecular typing for the MHC with PCR-SSP

Sequence-specific amplification (SSP) is simply a form of polymerase chain reaction (PCR) which involves designing one or both primers so that they will or will not allow amplification (the 3'-mismatch principle). Its origins are probably legion, i.e. many people probably thought of it at the same time. For example, in 1988 a group from Guy's Hospital, London, described a form of SSP for HLA-DR4 detection and in the same year a group from Upjohn described its use at the American Society of Histocompatibility and Immunogenetics (ASHI). Both are published in abstract form (British Society of Rheumatology and ASHI). The 3'-mismatch principle can be used to identify virtually any single nucleotide point mutation (SNP) within one or two PCR-SSP reactions and the first peer-reviewed statements of this came in 1989 (1, 2). Thus, although the use of SSP probably began around 1990, it was 5 years before its popularity erupted, mainly due to the work of Olerup & Zetterquist (3, 4), who defined its potential for solid organ transplantation. It is now the method of choice for high resolution HLA typing in many laboratories. In addition, over a thousand applications for genes outside the MHC are in the literature.

Lichen sclerosus in adult men: a study of HLA associations and susceptibility to autoimmune disease

Lichen sclerosus is a skin disorder of unknown prevalence affecting both men and women, and several studies have established HLA associations in women with this disease. Autoimmune disease associations in the form of a personal and/or family history of autoimmune disease have also been shown to be related to lichen sclerosus. In this study, we examined 58 men (mean age 38 years) with lichen sclerosus, 39 of whom had histologically proven disease. HLA tissue typing by phototyping was performed on these patients and contrasted with that of 602 control subjects. There was no difference in antigen frequencies of the HLA class I loci. The patient group was found to have an increased frequency of several HLA antigens of the class II loci: DR11, 13 of 58 (22%) patients vs. 75 of 602 (13%) control subjects (P = 0.05); DR12, five of 58 (9%) patients vs. 16 of 602 (3%) control subjects (P = 0.04); DQ7, 26 of 58 (45%) patients vs. 189 of 602 (31%) control subjects (P = 0.05). There were few autoimmune disease associations: two of 58 (3%) patients had a personal history of a different autoimmune disease, two patients were found to have abnormal thyroid function and six of 58 (10%) had a first-degree relative with an autoimmune disease. There was no difference in the frequency of the autoimmune haplotype HLA A1, B8, DR3/17, DQ2 compared with the control population. HLA DQ7 has now been shown to occur more frequently in both male and female patients with lichen sclerosus, which may reflect the immunopathogenesis of the disease. Autoimmune disease associations, however, are less common in men with lichen sclerosus.

A single BIR domain of XIAP sufficient for inhibiting caspases

The inhibitor of apoptosis proteins (IAPs) constitute an evolutionarily conserved family of homologous proteins that suppress apoptosis induced by multiple stimuli. Some IAP family proteins, including XIAP, cIAP-1, and cIAP-2, can bind and directly inhibit selected caspases, a group of intracellular cell death proteases. These caspase-inhibiting IAP family proteins all contain three tandem BIR domains followed by a RING zinc finger domain. To determine the structural basis for caspase inhibition by XIAP, we analyzed the effects of various fragments of this IAP family protein on caspase activity in vitro and on apoptosis suppression in intact cells. The RING domain of XIAP failed to inhibit the activity of recombinant caspases-3 or -7, whereas a fragment of XIAP encompassing the three tandem BIR domains potently inhibited these caspases in vitro and blocked Fas (CD95)-induced apoptosis when expressed in cells. Further dissection of the XIAP protein demonstrated that only the second of the three BIR domains (BIR2) was capable of binding and inhibiting these caspases. The apparent inhibition constants (Ki) for BIR2-mediated inhibition of caspases-3 and -7 were 2-5 nM, indicating that this single BIR domain possesses potent anti-caspase activity. Expression of the BIR2 domain in cells also partially suppressed Fas-induced apoptosis and blocked cytochrome c-induced processing of caspase-9 in cytosolic extracts, whereas BIR1 and BIR3 did not. These findings identify BIR2 as the minimal caspase-inhibitory domain of XIAP and indicate that a single BIR domain can be sufficient for binding and inhibiting caspases.