Meta-analysis and imputation identifies a 109 kb risk haplotype spanning TNFAIP3 associated with lupus nephritis and hematologic manifestations

TNFAIP3 encodes the ubiquitin-modifying enzyme, A20, a key regulator of inflammatory signaling pathways. We previously reported association between TNFAIP3 variants and systemic lupus erythematosus (SLE). To further localize the risk variant(s), we performed a meta-analysis using genetic data available from two Caucasian case-control datasets (1453 total cases, 3381 total control subjects) and 713 SLE trio families. The best result was found at rs5029939 (P=1.67 x 10(-14), odds ratio=2.09, 95% confidence interval 1.68-2.60). We then imputed single nucleotide polymorphisms (SNPs) from the CEU Phase II HapMap using genotypes from 431 SLE cases and 2155 control subjects. Imputation identified 11 SNPs in addition to three observed SNPs, which together, defined a 109 kb SLE risk segment surrounding TNFAIP3. When evaluating whether the rs5029939 risk allele was associated with SLE clinical manifestations, we observed that heterozygous carriers of the TNFAIP3 risk allele at rs5029939 have a twofold increased risk of developing renal or hematologic manifestations compared to homozygous non-risk subjects. In summary, our study strengthens the genetic evidence that variants in the region of TNFAIP3 influence risk for SLE, particularly in patients with renal and hematologic manifestations, and narrows the risk effect to a 109 kb DNA segment that spans the TNFAIP3 gene.

Genetic associations of LYN with systemic lupus erythematosus

We targeted LYN, a src-tyosine kinase involved in B-cell activation, in case-control association studies using populations of European-American, African-American and Korean subjects. Our combined European-derived population, consisting of 2463 independent cases and 3131 unrelated controls, shows significant association with rs6983130 in a female-only analysis with 2254 cases and 2228 controls (P=1.1 x 10(-4), odds ratio (OR)=0.81 (95% confidence interval: 0.73-0.90)). This single nucleotide polymorphism (SNP) is located in the 5' untranslated region within the first intron near the transcription initiation site of LYN. In addition, SNPs upstream of the first exon also show weak and sporadic association in subsets of the total European-American population. Multivariate logistic regression analysis implicates rs6983130 as a protective factor for systemic lupus erythematosus (SLE) susceptibility when anti-dsDNA, anti-chromatin, anti-52 kDa Ro or anti-Sm autoantibody status were used as covariates. Subset analysis of the European-American female cases by American College of Rheumatology classification criteria shows a reduction in the risk of hematological disorder with rs6983130 compared with cases without hematological disorders (P=1.5 x 10(-3), OR=0.75 (95% CI: 0.62-0.89)). None of the 90 SNPs tested show significant association with SLE in the African American or Korean populations. These results support an association of LYN with European-derived individuals with SLE, especially within autoantibody or clinical subsets.

Patients with familial and sporadic onset SLE have similar clinical profiles but vary profoundly by race

Few large, multi-ethnic studies have examined the clinical and serologic differences between familial and sporadic SLE patients. Understanding these similarities and differences is critical for interpreting genetic studies and developing therapeutic strategies. We compiled information on 1915 patients with SLE in a large multi-racial cohort, including general demographics, pedigree structure and the specific American College of Rheumatology (ACR) criteria met. One patient was randomly selected from each multiplex family for analysis, yielding 554 European-Americans (EA), 373 African-Americans (AA), 193 Hispanics (HI) and 237 patients of other of mixed races. When comparing familial and sporadic patients stratified by race, lupus erythematosus (LE) cells and arthritis were increased in white familial cases ( P = 5.5 × 10−6 and P = 0.028, respectively), but no other significant differences between familial and sporadic patients were found. We found that there were profound differences in clinical profiles between races. For example, photosensitivity and malar rash were decreased in AA ( P = 1.3 × 10−13 and 1.4 × 10−7, respectively), whereas discoid rash was increased in AA ( P = 5.5×10−6). EA had significantly less renal disease ( P = 5.4×10−13), proteinuria ( P = 4 × 10−12) and anti-Sm ( P = 1.7 × 10−12) than AA or HI. We, therefore, conclude that familial and sporadic onset patients may be treated similarly with respect to clinical and genetic studies.

Hydroxychloroquine sulfate treatment is associated with later onset of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a clinically diverse, complex autoimmune disease which may present with coincident onset of many criteria or slow, gradual symptom accrual. Early intervention has been postulated to delay or prevent the development of more serious sequelae. One option for treatment in this setting is hydroxychloroquine. Using 130 US military personnel who later met ACR SLE criteria, a retrospective study of onset, development and progression of SLE with and without pre-classification hydroxychloroquine (n = 26) use was performed. Patients treated with hydroxychloroquine prior to diagnosis had a longer (Wilcoxon signed rank test, P = 0.018) time between the onset of the first clinical symptom and SLE classification (median: 1.08 versus 0.29 years). Patients treated with prednisone before diagnosis also more slowly satisfied the classification criteria (Wilcoxon signed rank test, P = 0.011). The difference in median times between patients who received NSAIDs before diagnosis, as opposed to those who did not, was not different (P = 0.19). Patients treated with hydroxychloroquine also had a lower rate of autoantibody accumulation and a decreased number of autoantibody specificities at and after diagnosis. These findings are consistent with early hydroxychloroquine use being associated with delayed SLE onset. A prospective, blinded trial testing the capacity of hydroxychloroquine to delay or prevent SLE in high risk populations is warranted.

Genetic association of interleukin-21 polymorphisms with systemic lupus erythematosus

OBJECTIVE

The aetiology of systemic lupus erythematosus (SLE) is incompletely understood. Both genetic and environmental factors are implicated in the pathogenesis of the disease. Herein, we describe genetic association between SLE and polymorphisms in the interleukin (IL)-21 gene. The reported effect of IL-21 on B-cell differentiation into plasma cells and its effect on dendritic cell maturation and T-cell responses make IL-21 an attractive candidate gene for SLE.

METHODS

Three single nucleotide polymorphisms (SNPs) in the IL-21 gene were genotyped in a total of 2636 individuals (1318 cases and 1318 controls matched for age, sex and race). Population-based case-control association analyses were performed.

RESULTS

We found a genetic association with SLE and two SNPs located within the IL-21 gene (rs907715: chi(2) = 11.55, p<0.001; rs2221903: chi(2) = 5.49, p = 0.019). Furthermore, genotypes homozygous for the risk alleles were more frequent than genotypes homozygous for the non-risk alleles in European-American patients as compared to controls (rs907715 (GG versus AA): odds ratio (OR) = 1.66, p = 0.0049; rs2221903 (GG versus AA): OR = 1.60, p = 0.025).

CONCLUSION

Our findings indicate that IL-21 polymorphism is a candidate association with SLE. The functional effects of this association, when revealed, might improve our understanding of the disease and provide new therapeutic targets.

Familial aggregation and linkage analysis of autoantibody traits in pedigrees multiplex for systemic lupus erythematosus

Autoantibodies are clinically relevant biomarkers for numerous autoimmune disorders. The genetic basis of autoantibody production in systemic lupus erythematosus (SLE) and other autoimmune diseases is poorly understood. In this study, we characterized autoantibody profiles in 1,506 individuals from 229 multiplex SLE pedigrees. There was strong familial aggregation of antinuclear antibodies (ANAs), anti-double-stranded DNA (dsDNA), anti-La/SSB, anti-Ro/SSA, anti-Sm, anti-nRNP (nuclear ribonucleoprotein), IgM antiphospholipid (aPL) antibodies (Abs) and rheumatoid factor (RF) across these families enriched for lupus. We performed genome-wide linkage analyses in an effort to map genes that contribute to the production of the following autoantibodies: Ro/SSA, La/SSB, nRNP, Sm, dsDNA, RF, nuclear and phospholipids. Using an approach to minimize false positives and adjust for multiple comparisons, evidence for linkage was found to anti-La/SSB Abs on chromosome 3q21 (adjusted P=1.9 x 10(-6)), to anti-nRNP and/or anti-Sm Abs on chromosome 3q27 (adjusted P=3.5 x 10(-6)), to anti-Ro/SSA and/or anti-La/SSB Abs on chromosome 4q34-q35 (adjusted P=3.4 x 10(-4)) and to anti-IgM aPL Abs on chromosome 13q14 (adjusted P=2.3 x 10(-4)). These results support the hypothesis that autoantibody production is a genetically complex trait. Identification of the causative alleles will advance our understanding of critical molecular mechanisms that underlie SLE and perhaps other autoimmune diseases.

The helical tomotherapy thread effect

Inherent to helical tomotherapy is a dose variation pattern that manifests as a "ripple" (peak-to-trough relative to the average). This ripple is the result of helical beam junctioning, completely unique to helical tomotherapy. Pitch is defined as in helical CT, the couch travel distance for a complete gantry rotation relative to the axial beam width at the axis of rotation. Without scattering or beam divergence, an analytical posing of the problem as a simple integral predicts minima near a pitch of 1/n where n is an integer. A convolution-superposition dose calculator (TomoTherapy, Inc.) included all the physics needed to explore the ripple magnitude versus pitch and beam width. The results of the dose calculator and some benchmark measurements demonstrate that the ripple has sharp minima near p=0.86(1/n). The 0.86 factor is empirical and caused by a beam junctioning of the off-axis dose profiles which differ from the axial profiles as well as a long scatter tail of the profiles at depth. For very strong intensity modulation, the 0.86 factor may vary. The authors propose choosing particular minima pitches or using a second delivery that starts 180 deg off-phase from the first to reduce these ripples: "Double threading." For current typical pitches and beam widths, however, this effect is small and not clinically important for most situations. Certain extremely large field or high pitch cases, however, may benefit from mitigation of this effect.

Coinheritance of two rare genodermatoses (Papillon-Lefèvre syndrome and oculocutaneous albinism type 1) in two families: a genetic study

The co-occurrence of two rare recessive genetic conditions in apparently unrelated individuals or families is extremely rare. Two geographically distant and apparently unrelated families were identified in which individuals were simultaneously affected by two rare recessive mendelian syndromes, Papillon-Lefevre syndrome and type 1 oculocutaneous albinism. The families were tested for mutations in the causative genes, cathepsin C (CTSC) and tyrosinase (TYR), respectively, by direct sequencing. To assess the relationship of the two families, both families were tested for polymorphisms at eight microsatellite markers spanning both CTSC and TYR loci. Independent mutations (c.318-1G-->A and c.817G-->C/p.W272C) were identified in CTSC and TYR, respectively, that were shared by the affected individuals in both families. The two affected genes lie close together on chromosome bands 11q14.2-14.3, and studies with linked genetic markers suggested that the families shared a small chromosomal segment carrying both mutations that had been transmitted intact from a remote common ancestor. The co-occurrence of the two rare diseases in multiple families depends on their shared chromosomal location, but not on any shared pathogenic mechanism.

Quality assurance of a helical tomotherapy machine

Helical tomotherapy has been developed at the University of Wisconsin, and 'Hi-Art II' clinical machines are now commercially manufactured. At the core of each machine lies a ring-gantry-mounted short linear accelerator which generates x-rays that are collimated into a fan beam of intensity-modulated radiation by a binary multileaf, the modulation being variable with gantry angle. Patients are treated lying on a couch which is translated continuously through the bore of the machine as the gantry rotates. Highly conformal dose-distributions can be delivered using this technique, which is the therapy equivalent of spiral computed tomography. The approach requires synchrony of gantry rotation, couch translation, accelerator pulsing and the opening and closing of the leaves of the binary multileaf collimator used to modulate the radiation beam. In the course of clinically implementing helical tomotherapy, we have developed a quality assurance (QA) system for our machine. The system is analogous to that recommended for conventional clinical linear accelerator QA by AAPM Task Group 40 but contains some novel components, reflecting differences between the Hi-Art devices and conventional clinical accelerators. Here the design and dosimetric characteristics of Hi-Art machines are summarized and the QA system is set out along with experimental details of its implementation. Connections between this machine-based QA work, pre-treatment patient-specific delivery QA and fraction-by-fraction dose verification are discussed.

An investigation of the MEK/ERK inhibitor U0126 in acute myeloid leukemia

Blockade of mitogen-activated protein kinase kinase (MEK1/2), part of the extracellular signal-regulated kinase (ERK) or p44/42 mitogen-activated protein kinase (MAPK) pathway, has been shown in some instances to cause apoptosis in leukemic blast cells. This investigation examined the effect of the potent MEK/ERK inhibitor U0126 on apoptosis in acute myeloblastic leukemia (AML) cell lines, and acute leukemic and non-leukemic patient samples. The pro-apoptotic effect of the inhibitor varied across the five cell lines tested (KG1a, HEL, TF-1, MO7e, and THP-1) from highly significant induction of apoptosis to no apparent response. The pro-apoptotic effect of U0126 in the most sensitive cell line, KG1a, appeared to be related to its CD34 positivity. Three of five leukemic bone marrow samples showed considerable sensitivity to the inhibitor and a similar association with CD34 expression was evident. Interestingly, control marrow cells from six non-leukemic patients did not show a significant effect when exposed to U0126. These results suggest that this agent may offer a potential alternative to standard chemotherapy with a particular role in the most primitive types of leukemia, these often being the most resistant to standard chemotherapy.

Rapid clinical progression to diagnosis among African-American men with systemic lupus erythematosus

The initial clinical course of systemic lupus erythematosus (SLE) is variable, ranging from relatively minor manifestations progressing over years to rapid onset of fulminate disease. We sought to identify factors associated with the rapid manifestation of SLE. Chart review of military medical records was used to identify 130 patients who met the American College of Rheumatology classification criteria for SLE. Demographics, clinical criteria date of occurrence, and the date of SLE classification (at least four clinical criteria) met were documented. Prospectively stored serum samples prior to the diagnosis were evaluated for SLE autoantibodies. Median time from the first recorded criteria to diagnosis was significantly shorter in African-American (AA) males compared with AA females and European American (EA) females and males combined. AA males were more likely to have nephritis as their first clinical symptom. Also, less time transpired between the first clinical criterion and SLE diagnosis in AA males with nephritis than in other groups presenting with nephritis. Even when cases presenting with nephritis were excluded, a diagnosis of SLE was made more rapidly in AA males. African-American men progress from initial clinical manifestations to SLE diagnosis more rapidly than other ethnic or gender groups.

Immunization with peptides from 60 kDa Ro in diverse mouse strains

Antibodies binding the Ro (or SSA) and La (or SBB) proteins are commonly found in a high proportion of sera from patients with systemic lupus erythematosus or Sjögren's syndrome. The mechanism by which these autoantibodies arise is not known. Others and we have shown that immunization of nonautoimmune-prone mice with short peptides from the Ro ribonucleoprotein particle can induce autoimmunity to 60 kDa Ro and 52 kDa Ro as well as to the 48 kDa La protein after epitope spreading. We have explored the differences in the epitope spreading after 60 kDa Ro peptide immunization in several strains of mice. There is intra- and intermolecular diversification of the immune response after immunization of DBA/2J animals with a monomer peptide representing the residues 480-494 of the 60 kDa Ro protein, but this peptide does not induce epitope spreading when used as the immunogen in either C57Bl/6J or PL/J mice. Similar to previously studied BALB/c mice, DBA/2J mice have antibodies binding many epitopes of 60 kDa Ro, and some sera bind 52 kDa Ro as well as La. These mice have antinuclear antibody in their sera. These data demonstrate that Ro peptide immunization results in different outcomes depending upon the strain of mouse used. Furthermore, these data suggest that genetic variation is important with regard to responding towards short peptide immunization by epitope spreading.

Selective small antigenic structures are capable of inducing widespread autoimmunity which closely mimics the humoral fine specificity of human SLE

Recent data have suggested that autoantibodies in lupus can progress from simple immunity against a few antigenic structures to a complex response against multiple autoantigens. Our aim was to determine whether these diverse epitope patterns can indeed be generated by antigenic challenge with a single, small structure. Rabbits were immunized with either a 60 kDa Ro peptide commonly antigenic in human systemic lupus erythematosus (SLE) (Ro 274-289) or one which is rarely a humoral target (Ro 500-515). Rabbits immunized with the antigenic peptide (Ro 274-289) not only developed antibodies to multiple epitopes of 60 kDa Ro and La, as has been described, but also produced non-cross-reactive antibodies to the common spliceosomal proteins Sm B' and D1, and nRNP A and C. Rabbits immunized with the Ro 274-289 peptide also mount a progressive, diversified immune response to the sequential antigenic regions of these proteins (60 kDa Ro, Sm B' and D1, nRNP A and C), which is nearly identical to that seen in human SLE. Animals immunized with the nonantigenic peptide Ro 500-515 develop antibodies only to 60 kDa Ro. These results demonstrate that loss of tolerance to select single, small antigenic structures can begin a cascade which virtually recreates, at the epitope level, the humoral autoimmune specificity seen in human SLE.

The genetics of systemic lupus erythematosus stratified by renal disease: linkage at 10q22.3 (SLEN1), 2q34-35 (SLEN2), and 11p15.6 (SLEN3)

Renal disease occurs in 40-75% of systemic lupus erythematosus (SLE) patients and significantly contributes to morbidity and mortality. We used two pedigree stratification strategies to explore the impact of the ACR renal criterion for SLE classification upon genetic linkage with SLE. In both we used SLE as the phenotype. First, we evaluated genome scan data from >300 microsatellite markers in the 75 pedigrees that had at least one SLE affected with the SLE renal criterion. A maximum-likelihood parametric model approach produced a maximum screening LOD score of 3.16 at 10q22.3 in the European-American (EA) pedigrees. The African-American (AA) pedigrees obtained a maximum screening LOD score of 2.58 at 11p15.6. A multipoint sib-pair regression analysis produced P = 0.0000008 in EA at 10q22.3 (SLEN1) and P = 0.000001 in AA at 2q34-35 (SLEN2). A second stratification strategy explored the renal criterion in 35 pedigrees with two or more SLE patients with renal disease and produced a LOD score of 3.34 at 11p15.6 in AA (SLEN3). Sib-pair analysis in these 35 pedigrees revealed P = 0.00003 at 4q13.1 in EA, P = 0.00003 at 11p13 and 0.00007 at 3q23 in AA. Thus, multiple genetic linkages are related to the renal criterion in SLE. Of the significant genetic linkages with SLE described herein, those at 10q22.3 in the EA pedigrees (SLEN1) and at 2q34-35 in the AA pedigrees (SLEN2) have not been previously described.

A genome screen of systemic lupus erythematosus using affected-relative-pair linkage analysis with covariates demonstrates genetic heterogeneity

Systemic lupus erythematosus (SLE) appears to be the consequence of complex genetics and of only partly understood environmental contributions. Previous work by ourselves and by others has established genetic effects on 1q, 2q, 4p, 6p, and 16p using SLE as the phenotype. However, individual SLE affecteds are extraordinarily different from one another by clinical and laboratory measures. This variation may have a genetic basis; if so, it is advantageous to incorporate measures of between-family clinical variability as covariates in a genetic linkage analysis of affected relative pairs (ARPs) to allow for locus heterogeneity. This approach was applied to genome scan marker data from 160 pedigrees multiplex for SLE and containing 202 ARPs. Because the number of potential covariates was large, we used both ad hoc methods and formal principal components analysis to construct four composite covariates using the SLE classification criteria plus age of onset, ethnicity, and sex. Linkage analysis without covariates has detected evidence for linkage at 1q22-24, 2q37, 4p16, 12p12-11, and 17p13. Linkage analysis with these covariates uncovered linkage at 13p11, 17q11-25, and 20q12 and greatly improved evidence for linkage at 1q22-24, 2q37, 12p12-11, and 17p13. Follow-up analysis identified the original variables contributing to locus heterogeneity in each of these locations. In conclusion, allowing for locus heterogeneity through the incorporation of covariates in linkage analysis is a useful way to dissect the genetic contributions to SLE and uncover new genetic effects.

Genome scan stratified by the presence of anti-double-stranded DNA (dsDNA) autoantibody in pedigrees multiplex for systemic lupus erythematosus (SLE) establishes linkages at 19p13.2 (SLED1) and 18q21.1 (SLED2)

Anti-double-stranded DNA (anti-dsDNA) is arguably one of the most specific autoantibodies in systemic lupus erythematosus (SLE). This antibody is associated with more severe SLE and with glomerulonephritis. From 196 pedigrees multiplex for SLE, we selected those that had any SLE affected positive for anti-dsDNA by the Crithidia luciliae kinetoplast imunofluorescence assay. This stratification strategy tested the hypothesis that anti-dsDNA would identify a more genetically homogeneous group of pedigrees, in which previously undetected linkage effects could be established. A genome screen data for linkage to SLE was available at 307 microsatellite markers for this selected group of 71 pedigrees: 37 European-American, 29 African-American, and five others. The most significant results were obtained at 19p13.2 (LOD(max) = 4.93), named SLED1, in the 37 European-American pedigrees using a dominant model with mixed penetrances (92% for females and 49% for males) at 100% homogeneity (theta = 0). A second linkage effect, SLED2, was established in the 29 African-American pedigrees at 18q21.1 (LOD(max) = 3.40) using a recessive model with 100% penetrance (theta = 0.1). Parametric and non-parametric multipoint analyses were performed, which provided further evidence and support of susceptibility genes residing in these regions. In conclusion, two powerful linkages have been detected with SLE based on the presence of anti-dsDNA. These findings show SLE to be a richly complicated disease phenotype that is now ripe for important new discovery through a genetic approach.

Occlusal considerations in periodontics

Periodontal disease does not directly affect the occluding surfaces of teeth, consequently some may find a section on periodontics a surprising inclusion. Trauma from the occlusion, however, has been linked with periodontal disease for many years. Karolyi published his pioneering paper, in 1901 'Beobachtungen uber Pyorrhoea alveolaris' (occlusal stress and 'alveolar pyorrhoea'). (1) However, despite extensive research over many decades, the role of occlusion in the aetiology and pathogenesis of inflammatory periodontitis is still not completely understood.

Epitope mapping using the X-ray crystallographic structure of complement receptor type 2 (CR2)/CD21: identification of a highly inhibitory monoclonal antibody that directly recognizes the CR2-C3d interface

Complement receptor type 2 (CR2)/CD21 is a B lymphocyte cell membrane C3d/iC3b receptor that plays a central role in the immune response. Human CR2 is also the receptor for the EBV viral membrane glycoprotein gp350/220. Both C3d and gp350/220 bind CR2 within the first two of 15-16 repetitive domains that have been designated short consensus/complement repeats. Many mAbs react with human CR2; however, only one currently available mAb is known to block both C3d/iC3b and gp350/220 binding. We have used a recombinant form of human CR2 containing the short consensus/complement repeat 1-2 ligand-binding fragment to immunize Cr2(-/-) mice. Following fusion, we identified and further characterized four new anti-CR2 mAbs that recognize this fragment. Three of these inhibited binding of CR2 to C3d and gp350/220 in different forms. We have determined the relative inhibitory ability of the four mAbs to block ligand binding, and we have used overlapping peptide-based approaches to identify linear epitopes recognized by the inhibitory mAbs. Placement of these epitopes on the recently solved crystal structure of the CR2-C3d complex reveals that each inhibitory mAb recognizes a site either within or adjacent to the CR2-C3d contact site. One new mAb, designated 171, blocks CR2 receptor-ligand interactions with the greatest efficiency and recognizes a portion of the C3d contact site on CR2. Thus, we have created an anti-human CR2 mAb that blocks the C3d ligand by direct contact with its interaction site, and we have provided confirmatory evidence that the C3d binding site seen in its crystal structure exists in solution.

The role of Epstein-Barr virus in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a devastating autoimmune disease with no known cure. Lupus patients suffer from a myriad of clinical symptoms which variably include arthritis, pleuritis, pericarditis, vasculitis, and nephritis. The underlying mechanisms behind these clinical findings and the etiologic events preceding and causing disease onset, however, remain largely unknown. For many years, investigators have suspected that Epstein-Barr virus might somehow be involved in the etiology and/or pathogenesis of systemic lupus. Numerous studies have examined this possibility from various angles and have arrived at different conclusions. This work reviews these historical papers in the context of new results and presents a hypothetical role for this virus as an etiological environmental trigger for SLE.

Tacrolimus is not associated with gingival overgrowth in renal transplant patients

BACKGROUND

Cyclosporin A is used extensively to prevent the rejection of allogenic renal transplants. However, it is associated with a variety of undesirable side effects including gingival overgrowth. Tacrolimus (FK506), has been marketed as an effective alternative immunosuppressant to cyclosporin A and recent subjective reports suggest patients taking it complain infrequently of gingival problems. This clinical investigation was undertaken to confirm whether or not tacrolimus adversely affected the gingival health of renal transplant recipients.

METHODS

Renal transplant patients (RTPs) under the care of the Renal Transplantation Service at the Manchester Royal Infirmary, who had received a renal allograft at least 18 months earlier, were recruited for this study. All but one of the RTPs had been taking tacrolimus since transplantation. The other had commenced tacrolimus therapy two months after receiving her allograft. A hospital based control group was recruited from non transplanted individuals attending the Turner Dental School, Manchester. Each patient underwent a detailed dental assessment and had dental impressions taken. The extent of gingival overgrowth was determined from plaster models.

RESULTS

25 renal transplant recipients and 26 control patients were included in the study. None of the individuals in either the tacrolimus or control groups had clinically significant overgrowth. The patients in the tacrolimus group with the highest overgrowth scores were those also taking calcium antagonists as treatment for hypertension.

CONCLUSION

This study demonstrates that tacrolimus has no adverse effects on the gingival tissues and thus has potential as an alternative immunosuppressant for individuals susceptible to developing cyclosporin A-induced gingival overgrowth.

Role of viruses in systemic lupus erythematosus and Sjögren syndrome

Systemic lupus erythematosus and Sjögren syndrome remain elusive in the description of their underlying etiologic causes and pathogenic mechanisms. Although underlying genetic predisposition appears to contribute to both diseases based on twin and other genetic studies, additional factors must play a role. Over the decades additional factors, such as hormonal influence, UV light, environmental exposures (e.g., silica, solvents), and infectious agents have been postulated to play a role. Over the past few years additional information has been published concerning roles of various infectious agents in both lupus and Sjögren syndrome. Although the understanding of this field is still incomplete, significant advances are being made.

Lupus autoantibodies recognize the product of an alternative open reading frame of SmB/B'

An unusual feature of the gene for the spliceosomal protein SmB/B' is the presence of an unusually long alternative open reading frame (aORF) which could encode 220 amino acids. We cloned and expressed this aORF protein and used immunological assays to determine its antigenicity in patients with systemic lupus. Sera from 10 of 22 (46%) anti-Sm positive lupus patients showed significant binding to the SmB' aORF protein by ELISA while neither the normal controls nor anti-Sm negative lupus patient controls showed significant reactivity. Antigenicity of the SmB' aORF protein was further localized to the C-terminus using a deletion construct. This is the first known example in which the product of an alternative open reading frame acts as an autoantigen in human disease. These results are consistent with the possibility that generation of anti-Sm autoantibodies in a subset of lupus patients is due to abnormal processing and expression of an aORF SmB/B' message, by an as yet unidentified mechanism.

Development of anti-dsDNA autoantibodies prior to clinical diagnosis of systemic lupus erythematosus

Anti-double stranded (dsDNA) antibodies are of considerable diagnostic value and are thought to be involved in the pathogenesis of systemic lupus erythematosus (SLE). Fluctuations in anti-dsDNA antibody levels are also used as markers for disease activity and exacerbations. In this study we sought to evaluate the anti-dsDNA antibody level in serum samples collected before the onset of SLE diagnosis. A total of 130 SLE patients were identified with stored serum samples available prior to diagnosis within the US Department of Defense serum repository. All 633 sera available from these patients were screened for anti-dsDNA antibodies using an enzyme linked immunosorbant assay (ELISA). Within this cohort 55% of cases had detectable anti-dsDNA antibodies prior to SLE diagnosis. The onset of anti-dsDNA antibodies ranged from 9.3 years before to within the same month as diagnosis (with a mean onset 2.7 years before diagnosis). In order to assess for fluctuations in anti-dsDNA levels relative to diagnosis, cases were selected with at least two positive samples, one within 6 months and a second greater than 6 months prior to diagnosis (n = 26). Seven of these cases also had samples available shortly after diagnosis (< or = 6 months) for comparison. Fifty-eight percent of the 26 cases developed a significant rise in anti-dsDNA antibody levels within 6 months of diagnosis. A significant decline in anti-dsDNA levels ensued after diagnosis (and following treatment with corticosteroids) in all seven cases with samples available. Patients with a significant rise in anti-dsDNA antibodies at diagnosis were more likely to have renal disease than those who did not (66.7% compared to 27.3%, chi2 =3.94, P<0.05). These data suggest that anti-dsDNA antibodies are present in SLE patient sera much earlier than previously suspected. In addition, the data are consistent with increases in anti-dsDNA levels contributing to the onset of clinical illness in some patients with SLE.