The immunogenetic relationship between anti-Ro(SS-A)/La(SS-B) antibody positive Sjögren's/lupus erythematosus overlap syndrome and the neonatal lupus syndrome

Pervasive Sharing of Causal Genetic Risk Factors Contributes to Clinical and Molecular Overlap between Sjögren's Disease and Systemic Lupus Erythematosus

SjD (Sjögren's Disease) and SLE (Systemic Lupus Erythematosus) are similar diseases. There is extensive overlap between the two in terms of both clinical features and pathobiologic mechanisms. Shared genetic risk is a potential explanation of this overlap. In this study, we evaluated whether these diseases share causal genetic risk factors. We compared the causal genetic risk for SLE and SjD using three complementary approaches. First, we examined the published GWAS results for these two diseases by analyzing the predicted causal gene protein-protein interaction networks of both diseases. Since this method does not account for overlapping risk intervals, we examined whether such intervals also overlap. Third, we used two-sample Mendelian randomization (two sample MR) using GWAS summary statistics to determine whether risk variants for SLE are causal for SjD and vice versa. We found that both the putative causal genes and the genomic risk intervals for SLE and SjD overlap 28- and 130-times more than expected by chance (p < 1.1 × 10-24 and p < 1.1 × 10-41, respectively). Further, two sample MR analysis confirmed that alone or in aggregate, SLE is likely causal for SjD and vice versa. [SjD variants predicting SLE: OR = 2.56; 95% CI (1.98-3.30); p < 1.4 × 10-13, inverse-variance weighted; SLE variants predicting SjD: OR = 1.36; 95% CI (1.26-1.47); p < 1.6 × 10-11, inverse-variance weighted]. Notably, some variants have disparate impact in terms of effect size across disease states. Overlapping causal genetic risk factors were found for both diseases using complementary approaches. These observations support the hypothesis that shared genetic factors drive the clinical and pathobiologic overlap between these diseases. Our study has implications for both differential diagnosis and future genetic studies of these two conditions.

The HLA locus contains novel foetal susceptibility alleles for congenital heart block with significant paternal influence

OBJECTIVE

The main aim of this study was to identify foetal susceptibility genes on chromosome six for Ro/SSA autoantibody-mediated congenital heart block.

SUBJECTS AND DESIGN

Single nucleotide polymorphism (SNP) genotyping of individuals in the Swedish Congenital Heart Block (CHB) study population was performed. Low-resolution HLA-A, -Cw and -DRB1 allele typing was carried out in 86 families comprising 339 individuals (86 Ro/SSA autoantibody-positive mothers, 71 fathers, 87 CHB index cases and 95 unaffected siblings).

RESULTS

A case-control comparison between index cases and population-based out-of-study controls (n = 1710) revealed association of CHB with 15 SNPs in the 6p21.3 MHC locus at a chromosome-wide significance of P < 2.59 × 10(-6) (OR 2.21-3.12). In a family-based analysis of association of SNP markers as well as distinct MHC class I and II alleles with CHB, HLA-DRB1*04 and HLA-Cw*05 variants were significantly more frequently transmitted to affected individuals (P < 0.03 and P < 0.05, respectively), whilst HLA-DRB1*13 and HLA-Cw*06 variants were significantly less often transmitted to affected children (P < 0.04 and P < 0.03). We further observed marked association of increased paternal (but not maternal) HLA-DRB1*04 transmission to affected offspring (P < 0.02).

CONCLUSIONS

HLA-DRB1*04 and HLA-Cw*05 were identified as novel foetal HLA allele variants that confer susceptibility to CHB in response to Ro/SSA autoantibody exposure, whilst DRB1*13 and Cw*06 emerged as protective alleles. Additionally, we demonstrated a paternal contribution to foetal susceptibility to CHB for the first time.

Race differences in immunogenetic features and photosensitivity of cutaneous lupus erythematosus from the aspect of Japanese studies

Skin lesions of collagen diseases are influenced by environmental triggers, such as UV light, and are variable in cutaneous lupus erythematosus (LE), such as systemic LE (SLE), chronic discoid LE (CDLE), subacute cutaneous LE (SCLE), and LE tumidus (LET). Although there are a few conflicting reports on photosensitivity in collagen diseases, many Japanese dermatologists feel there are photosensitivity differences in LE between Asians and Caucasians with SCLE and LET. To address this issue, we have carried out genetic studies of Japanese SLE and CDLE patients and reviewed the race differences in photosensitivity of cutaneous LE from Japanese studies. Human leukocyte antigen (HLA) studies in Japanese patients revealed that HLA-DRB1*1501 association was with CDLE and SLE. The association between HLA-Cw6 and CDLE was first reported in a Japanese population, and a HLA-A33-B44-DRB1*1302 haplotype showed a positive association in CDLE. However, these results are not compatible with those from Caucasian subjects. There are no significant associations among HLA studies, photosensitivity, and anti-Ro/SS-A antibodies in Japanese CLE patients. Photosensitivity will be a key factor to dissolve multifactorial complexes of LE etiopathogenesis. An axis of photosensitivity, anti-Ro/SS-A antibodies, and apoptosis via tumor necrosis factor-alpha is the best marker to verify the contribution of genetics in CLE patients. The incidence and degree of photosensitivity of SCLE and LET are much lower in Japanese than in Caucasians. This discrepancy may lead to investigations of CLE pathogenesis through global collaborations.

Induction of Oral Tolerance in Experimental Sjogren's Syndrome Autoimmunity

Previous studies have showed that immunization with peptides from Ro 60 results in Sjogren's syndrome (SS)-like condition in BALB/c mice. We hypothesized that oral feeding with Ro 60 peptide or Ro 60 would prevent the disease. Four groups (each consisting of 10) of BALB/c mice were used. Group I-III were immunized with Ro 274 peptide. Group IV mice were administered adjuvant only. Group II mice were fed orally with Ro 274 peptide and Group III with Ro 60 for 5 days before immunization. There was a significant reduction in the binding of sera from both Group II and Group III mice to most of the Ro multiple antigenic peptides bound by Group I mice. In Group III mice, salivary flow was maintained above that of the Group I mice (average: 117.5 versus 58.6 microl; t = 2.7; P = 0.02). Salivary infiltrates were drastically decreased in the Ro peptide or Ro 60-fed groups, compared to non-tolerized group. Two of eight mice in Group II and 3/6 mice in Group III had no infiltrates, whereas all eight mice studied in Group I had a significant number of infiltrates. Thus, epitope spreading was prevented, lymphocytic infiltration was blocked and saliva flow was restored by means of oral feeding of either Ro 274 or Ro 60 in this animal model of SS.

Sjögren's syndrome associated with systemic lupus erythematosus: Clinical and laboratory profiles and comparison with primary Sjögren's syndrome

OBJECTIVE

To address the clinical, serologic, pathologic, and immunogenetic features of sicca syndrome that occurs in systemic lupus erythematosus (SLE), as well as its similarities to, and differences from, sicca syndrome that occurs in primary Sjögren's syndrome (SS).

METHODS

A cohort of 283 consecutive unselected SLE patients was evaluated for the presence of associated SS using the American-European classification criteria. Clinical and laboratory parameters in SLE patients with SS (SLE-SS) were compared with those in SLE patients without SS (SLE-no SS) and with a group of 86 unselected patients with primary SS.

RESULTS

SS was identified in 26 SLE patients (9.2%); the SS preceded the development of lupus in 18 of them (69.2%). Compared with the SLE-no SS group, patients with SLE-SS were significantly older, had a higher frequency of Raynaud's phenomenon, anti-Ro/SSA, anti-La/SSB, and rheumatoid factor, but had a significantly lower frequency of renal involvement, lymphadenopathy, and thrombocytopenia. Compared with the primary SS group, SLE-SS patients displayed a clinically similar sicca syndrome, but were significantly younger and had an increased frequency of perivascular infiltrates in the salivary glands associated with anticardiolipin antibodies in the serum. SLE-SS patients had a high frequency of the DRB1*0301 allele. This HLA profile distinguished the SLE-SS group from the SLE-no SS group, who had an increased frequency of DRB1*1501 and DQB1*0602 alleles, but was similar to the HLA profile of the primary SS group, who had an increased frequency of DRB1*0301.

CONCLUSION

SLE-SS appears to constitute a subgroup of patients with distinct clinical, serologic, pathologic, and immunogenetic features, in whom SS is expressed as an overlapping entity and is largely similar to primary SS.

DNA typing of maternal HLA in congenital complete heart block: comparison with systemic lupus erythematosus and primary Sjögren's syndrome

OBJECTIVE

To investigate which maternal HLA allele or haplotype is primarily associated with isolated congenital complete heart block (CCHB) in offspring.

METHODS

HLA class II typings were assessed by line probe assay and polymerase chain reaction-sequence-specific oligonucleotide probe methods, and HLA class I by the microlymphocytotoxicity test, in 13 Italian anti-Ro-positive mothers of children with CCHB and 41 anti-Ro-positive mothers with healthy children (20 mothers with systemic lupus erythematosus [SLE] and 21 with Sjögren's syndrome [SS]). Anti-Ro antibodies were studied by immunoblot.

RESULTS

HLA-DRB1*03011 and DRB1*03011; DQA1*0501;DQB1*0201 were more frequent in mothers of infants with CCHB than in mothers who had SLE, but not in mothers who had SS and whose children were healthy. Mothers of infants with CCHB were either HLA-B5/35, B17, or B44 positive and had a higher prevalence of B44;DRB11;DQA1*0501;DQB1*0301 and isolated anti-52-kd antibodies, which were absent in SS and SLE controls.

CONCLUSION

Mothers of infants with CCHB presented a strong genetic similarity to mothers who had SS, except for HLA class I phenotype. HLA-DRB1*03011;DQA1*0501;DQB1*0201 seemed not to be primary CCHB-associated genes, but were involved in an SS-like anti-Ro/La response. The combined presence of HLA-DRB1*03011 and anti-52-kd SSA/Ro antibodies conveyed the highest risk of giving birth to an affected child.

Sjögren autoantibodies modify neonatal cardiac function via M1 muscarinic acetylcholine receptor activation

Isolated congenital heart block may be associated with primary Sjögren syndrome. In this work we describe circulating antibodies in the sera of primary Sjögren syndrome patients that are able to interact with neonatal myocardium by activating muscarinic acetylcholine receptors of M1 subtype. We report on the presence of autoantibodies against the second extracellular loop of human M1 muscarinic acetylcholine receptors in primary Sjögren syndrome mothers whose children have congenital heart block using a synthetic peptide in indirect immunofluorescence technique. Autoantibodies from primary Sjögren syndrome patients gave positive image on neonatal atria but not on adult atria slices. The synthetic M1 peptide selectively abrogated indirect immunofluorescence recognition. The primary Sjögren syndrome-immunoglobulin G also displayed an 'agonist like' activity modifying the intracellular events associated with muscarinic acetylcholine receptor activation. The mechanism appears to occur secondarily to stimulation of phosphoinositides turnover via phospholipase C activation. This, in turn, triggers cascade reactions involving calcium/calmodulin and leads to activation of nitric oxide synthase and soluble guanylate cyclase. All of these effects were selectively blunted by pirenzepine and neutralized by M1 synthetic peptide. These biological effects were not obtained using adult instead of neonatal rat atria and neither occurred with the sera of normal healthy women of childbearing age. It could be concluded that antibodies against neonatal M1 muscarinic acetylcholine receptor may be another serum factor to be considered in the pathophysiology of the development of congenital heart block associated with primary Sjögren syndrome mothers.

Neonatal lupus erythematosus: studies on HLA class II genes and autoantibody profiles in Japanese mothers

Neonatal lupus erythematosus (NLE) is a rare disorder of neonates characterized by two major clinical manifestations: congenital heart block and cutaneous lupus lesions. The disease is associated with placentally transferred maternal anti-Ro/SSA and/or La/SSB antibodies. To clarify possible class II HLA associations with maternal autoantibody responses, haplotypic and allelic distributions, along with the polymorphism of the MHC class II HLA alleles, were analyzed based on PCR-RFLP results in 25 Japanese mothers of two groups defined by precipitating autoantibody profiles. Among mothers with both anti-Ro/SSA and anti-La/SSB antibodies, but not those with anti-Ro/SSA alone, the class II haplotypes DRB1*1101-DQA1*0501-DQB1*0301 and DRB1*08032-DQA1*0103-DQB1*0601 as well as individual class II alleles DRB1*1101, DRB1*08032 and DQB1*0301 showed significantly increased frequencies compared to those in normal controls. All anti-Ro/SSA and anti-La/SSB positive mothers carried DRB1 alleles that shared the same amino acid residues at positions 14-31 and 71 of the DRB1 chain. These mothers also carried homozygous or heterozygous DQ6 and DQ3 alleles that shared the same amino acid residues at positions 27-36 and 71-77 of hypervariable regions of the DQB1 chain. Furthermore, all mothers with both anti-Ro/SSA and anti-La/SSB were homozygous for DPB1*0501. Nine of 10 anti-Ro/SSA and anti-La/SSB-positive mothers, but only 6 of 15 mothers with anti-Ro/SSA alone, had affected infants. Thus, our findings suggest that there may be immunogenetic differences among mothers according to their autoantibody profiles, and that mothers with both anti-Ro/SSA and anti-La/SSB are more likely to have infants with NLE than mothers with anti-Ro/SSA alone.

Spongiotic annular erythema in SS-A/SS-B antibody negative Sjögren's syndrome

We reported four cases of Sjögren's syndrome (SjS) who manifested a new type of annular erythema that differs from the previously described annular erythema seen in anti-SS-A/SS-B antibody positive SjS in both clinical and histological findings. Characteristic histological features are the presence of spongiotic changes around the acrosyringium and perivascular lymphocytic infiltration without liquefaction degeneration or epidermal change, suggesting lupus erythematosus. No complement or immunoglobulin depositions are demonstrated along the basement membrane zone or around blood vessels. Clinically, this type of erythema usually appears on the trunk or extremities with itchy sensations, especially in summer, which contrasts with the preferential occurrence of the previously reported SjS related annular erythema on the facial skin in winter. Immunologically, all four cases lacked anti-SS-A and anti-SS-B antibodies, but possessed positive anti-microsome antibodies or thyroid tests. In three cases, metal allergy was demonstrated by patch test, which might suggest that the sweat duct is the primary target of excreted metals in this condition and that underlying SjS might play some role in the higher prevalence of metal allergy or in induction of sweat duct injury, similar to the interstitial nephritis which is now thought to be an exocrine manifestation of SjS.

Neonatal lupus erythematosus: HLA-DR and -DQ distributions are different among the groups of anti-Ro/SSA-positive mothers with different neonatal outcomes

Neonatal lupus erythematosus (NLE) is an antibody-mediated disorder of infants characterized by two major clinical manifestations; cutaneous lupus lesions and congenital heart block (CHB). The disease is associated with placentally transferred maternal anti-Ro/SSA and/or La/SSB antibodies. There is a tendency for the same disease expression to occur within a sibship. To reveal a possible association of class II MHC genes with maternal anti-Ro/SSA autoimmune responses and neonatal outcomes in NLE with a relatively homogeneous ethnic background, haplotype, and allele distributions were analyzed based on the PCR-RFLP results in 26 Japanese anti-Ro/SSA-positive mothers from three groups defined by neonatal outcomes. The results were as follows: (i) maternal HLA-DR5 haplotype DRB1*1101-DQA1*0501-DQB1*0301 and individual class II alleles making up this haplotype were significantly associated with neonatal cutaneous lupus but not CHB. Conversely, maternal HLA-DQB1*0602 carried on HLA-DR2 haplotypes was associated with CHB but not cutaneous NLE; (ii) HLA-DQA1 alleles with glutamine at position 34 of the first domain, which have reportedly been associated with the autoimmune responses to Ro/SSA antigens in other ethnic groups, were increased in the mothers of infants with cutaneous involvement; and (iii) there was no particular class II HLA profile that distinguished the disease manifestations in infants. These findings suggest that specific maternal MHC class II genes might correlate with specific neonatal outcomes in NLE.

Neonatal lupus erythematosus related to maternal leukocytoclastic vasculitis

Neonatal lupus erythematosus (NLE) is an autoimmune disease whose major findings are skin lesions and congenital heart block. Affected infants have maternal, transplacentally acquired, autoantibodies to Ro/SSA, La/SSB, or U1-RNP antigens. Anti-Ro/SSA is the predominant autoantibody, present in about 95% of cases. Mothers of babies with NLE may be asymptomatic initially or may have Sjögren syndrome, lupus erythematosus, overlap syndrome or, uncommonly, leukocytoclastic vasculitis. When evaluating a young woman with a cutaneous leucocytoclastic vasculitis, dermatologists should be aware of the possible presence of antibodies related to NLE. If any patient suffering a disorder related to NLE becomes pregnant, testing for autoantibodies and close obstetric prenatal care with fetal echocardiogram is necessary. In cases of fetal bradycardia, treatment with dexamethasone or betamethasone should be considered, as these drugs are accessible to the fetal circulation.

Neonatal lupus erythematosus: analysis of HLA class II alleles in mothers and siblings from seven Japanese families

BACKGROUND

Neonatal lupus erythematosus (NLE) is a syndrome characterized by dermatitis and congenital heart block. The disease is mostly associated with transplacental passage of maternal anti-Ro(SS-A) or anti-La(SS-B) antibodies. Maternal HLA-DR3 and DQ2 alleles are associated with NLE in white and North American black populations.

OBJECTIVE

We sought evidence of a potential genetic disposition to NLE in mothers with a relatively homogeneous ethnic background.

METHODS

Class II human major histocompatibility complex HLA-DRB1, DQA1, DQB1, and DPB1 alleles were determined by polymerase chain reaction-restriction fragment length polymorphism in anti-Ro(SS-A)-positive mothers as well as in infants from seven Japanese families with siblings concordant or discordant for disease expression of NLE.

RESULTS

All seven mothers had two or three DQ alleles of DQA1 and DQB1 possessing specific amino acid residues, which are reportedly associated with anti-Ro(SS-A) autoantibody response in white and black populations. There was no class II HLA profile that distinguished disease manifestations of NLE in infants.

CONCLUSION

The HLA class II allele associations with anti-Ro(SS-A) autoantibodies that have been noted in other ethnic groups were also found in Japanese anti-Ro(SS-A)-positive mothers whose infants had NLE, suggesting shared susceptibility factors across racial barriers in maternal predisposition to Ro(SS-A) autoimmune response.

Circulating antibodies against neonatal cardiac muscarinic acetylcholine receptor in patients with Sjögren's syndrome

Isolated congenital heart block may be associated with Primary Sjögren's Syndrome. In this work we demonstrated that IgG present in the sera of patients with Primary Sjögren's Syndrome (PSS) could bind and activate muscarinic acetylcholine receptors of rat neonatal atria. These antibodies were able to inhibit in a irreversible manner the binding of 3H-QNB to muscarinic cholinergic receptors of purified rat atria membranes. Moreover, IgG from PSS individuals could modify biological effects mediated by muscarinic cholinoceptors activation, i.e. decrease contractility and cAMP and increase phosphoinositide turnover and cGMP. Atropine blocked all of these effects and carbachol mimicked them; confirming muscarinic cholinergic receptors-mediated PSS IgG action. Neither binding nor biological effect were obtained using adult instead of neonatal rat atria. IgG from sera of normal women were not effective in the studied system. The prevalence of cholinergic antibody was 100% in PSS and was independent of Ro/SS-A and La/SS-B antibodies. It could be concluded that antibody against muscarinic cholinergic receptors may be another serum factor to be considered in the pathophysiology of the development of congenital heart block.

Neonatal lupus erythematosus in an infant with Turner syndrome

Neonatal lupus erythematosus (NLE) is characterized by transient, annular cutaneous lesions, congenital heart block, and a variety of systemic or hematologic abnormalities. We describe a white infant girl with onset of skin lesions on the face and scalp at 4 days of age. At age 4 weeks she had generalized, erythematous, scaly, annular skin lesions that underwent spontaneous regression at age 5 months. Her mother had no cutaneous or other lesions, but complement examinations revealed the presence of anti-Ro(SSA) and anti-La(SSB) antibodies, and absence of anti-Sm and anti-RNP antibodies. Karyotyping revealed Turner syndrome (TS) with 45,XO sex chromosome constitution. Ro(SSA) and La(SSB) antibodies were found, and direct immunofluorescence testing on healthy skin was positive. At age 5 months, follow-up immunologic examination of the infant had normal results but the mother still had anti-Ro(SSA) and anti-La(SSB) antibodies. We believe that this is the first reported case of NLE in association with TS.

Neonatal lupus erythematosus: discordant disease expression of U1RNP-positive antibodies in fraternal twins--is this a subset of neonatal lupus erythematosus or a new distinct syndrome?

Neonatal lupus erythematosus (NLE) is an uncommon disease that is manifested by cutaneous lesions, cardiac conduction defects, or both, that appear in utero or shortly after birth. In approximately 95% of patients, anti-Ro antibody (Ro[SS-A]) has been identified and has become the serologic marker for NLE. Since 1987 there have been four reported cases of Ro- and anti-La antibody (La[SS-B])-negative, U1RNP antibody-positive, NLE. Our affected twin, as well as all other infants with U1RNP-positive NLE, had cutaneous lesions similar to those in Ro-positive NLE, although they lacked systemic abnormalities, including cardiac conduction defects. HLA typing of mothers with infants with U1RNP-positive NLE revealed the presence of HLA-DR4, DQw1, or DQw3 phenotypes. Our typing confirms these findings. As with Ro-positive NLE, no distinct HLA associations were demonstrated in the infants. Unlike Ro-positive mothers, all mothers with a U1RNP-positive infant with NLE had connective tissue disease at the time of the diagnosis and had a different spectrum of disease. We describe the clinical, serologic, and immunogenetic findings in the first reported case of U1RNP-positive NLE in dizygotic twins in whom the NLE disease expression was discordant.

La (SS-B)-positive neonatal lupus erythematosus: report of a case with unusual features

Neonatal lupus erythematosus is most often associated with autoantibodies against Ro and La antigens. Rarely, neonatal lupus erythematosus occurs in the absence of Ro antibody. We present a case of La antibody-positive neonatal lupus erythematosus with unusual features.

Neuropsychiatric disease in Sjögren's syndrome: anti-ribosomal P and anti-neuronal antibodies

PURPOSE

Patients with Sjögren's syndrome (SS) may develop nonfocal (i.e., psychiatric and/or cognitive dysfunction) as well as focal, neuropsychiatric disease (CNS-SS). Anti-ribosomal P and anti-neuronal antibodies have been associated with nonfocal neuropsychiatric disease in systemic lupus erythematosus (SLE), particularly psychosis and depression. This study examines the spectrum of psychiatric and cognitive dysfunction observed in SS patients with focal, as well as nonfocal, central nervous system (CNS) disease and relates these observations to the presence of serum and cerebrospinal fluid (CSF) anti-ribosomal and anti-neuronal antibodies.

PATIENTS AND METHODS

One hundred thirty-one patients--patients with primary SS (n = 91), patients with secondary SS (n = 34), and mothers of infants with neonatal lupus erythematosus (NLE) (n = 6)--were studied. Patients were referred to a large tertiary referral center and the population was highly selected for CNS disease. Patients were evaluated clinically for focal and nonfocal CNS disease. Sera from 131 patients and 34 paired sera/CSF samples were examined by enzyme-linked immunosorbent assay and radioimmunoassay for the presence of anti-ribosomal P and anti-neuronal autoantibodies, respectively. Clinical features were categorized and autoantibody profiles obtained and correlated independently for statistical significance. Data were analyzed using the two-tailed Fisher exact test.

RESULTS

Psychiatric or cognitive impairment, usually mild or moderate, occurred in over 80% (63 of 77) of this highly selected population of SS patients, and more than 60% of patients (48 of 77) had both. Anti-ribosomal P antibodies occurred in six (4.6%) patients with SS and related disorders. None of the patients with primary SS had anti-ribosomal P antibodies, whereas they were present in a small number of patients with secondary SS (i.e., 4 of 34 [12%]) and in 2 of 6 mothers of infants with NLE. There was no correlation between nonfocal CNS disease, including psychosis or severe depression, and the presence of anti-ribosomal P antibodies. Paired serum CSF samples from 34 SS patients with active CNS disease, including 6 with psychosis and 5 with severe depression, did not contain either anti-ribosomal P or anti-neuronal antibodies. Anti-ribosomal P and anti-neuronal antibodies were present in a control subset of SLE patients defined serologically by the presence of anti-nDNA antibodies.

CONCLUSION

Patients with primary SS associated with CNS disease, including psychosis and depression, do not have serum or CSF autoantibodies to ribosomal P peptide or neuronal antigens, detected by binding to neuroblastoma cells. Thus, autoantibodies associated with nonfocal or diffuse CNS disease in classical SLE (particularly psychosis and depression) are not present in CNS-SS. The observations suggest that nonfocal CNS disease in CNS-SS and CNS-SLE may be mediated by different immunopathologic mechanisms. Potentially, these observations may have diagnostic and therapeutic implications in the management of patients with CNS-SS and patients with CNS-SLE.

Anti-Ro(SS-A) HLA-DR3-positive women: the interrelationship between some ANA negative, SS, SCLE, and NLE mothers and SS/LE overlap female patients

During the past 15 years, the clinical spectrum associated with the anti-Ro(SS-A) antibody response has been defined. Various clinical presentations, including subacute cutaneous lupus erythematosus, the neonatal lupus syndrome, the Sjögren's syndrome/lupus erythematous overlap syndrome, and primary Sjögren's syndrome, have been detected in association with the anti-Ro(SS-A) response. The anti-Ro(SS-A) antibody response is associated with the HLA-DR2 and HLA-DR3 phenotypes. There is now a good deal of evidence to suggest that many anti-Ro(SS-A)-positive HLA-DR3 women are genetically closely related, sharing in common an enriched frequency of the HLA-DR3-linked B8, DQw2, and DRW52 phenotypes. DNA sequence studies have confirmed this genetic relationship. These studies have led us to the following conclusions. 1) The HLA-DR2 and HLA-DR3 associations with systemic lupus erythematosus and the HLA-DR3 association with Sjögren's syndrome are related to the anti-Ro(SS-A) antibody response and not to the clinical disease expression. 2) HLA-DR3 anti Ro-positive female patients with first-degree Sjögren's syndrome, subacute cutaneous lupus erythematosus, or Sjögren's syndrome, or who are asymptomatic, are immunogenetically closely related even though the clinical presentations are strikingly different. All these HLA-DR3 anti-Ro(SS-A) antibody-positive women are at risk to give birth to a child with the neonatal lupus syndrome.

Immunogenetic study of three Japanese families with neonatal lupus erythematosus

We encountered three Japanese families with neonatal lupus erythematosus. None of the three fathers showed any signs of collagen disease. The three mothers were found to suffer from Sjögren's syndrome; they all tested positive for anti-SSA and SSB antibodies and had lymphocyte infiltration into the small salivary gland. In two families, one child had neonatal lupus erythematosus while a sibling was normal; in the third family, both children had neonatal lupus erythematosus. Thus, a mother with positive anti-SSA and SSB antibodies can give birth to one infant with and one infant without or have two infants with neonatal lupus erythematosus. We conducted HLA typing of all 12 members of the three families in order to clarify the immunologic factors involved. We found no increased frequency of any HLA phenotype in the three mothers and their four children with neonatal lupus erythematosus; however, HLA-DR4 was present in three of the children with neonatal lupus erythematosus.

Neonatal lupus erythematosus in Japan

BACKGROUND

Although more than 200 cases of neonatal lupus erythematosus (NLE) have been reported, the prognosis, clinical characteristics, and genetic background of the patients are still obscure. Their symptoms seem to vary in different races.

OBJECTIVE

We had an opportunity to see two clinically different types of NLE. It is important to define the clinical characteristics in Japanese cases and to compare them to caucasian NLE cases reported earlier.

METHODS

Sixty Japanese infants with NLE and their mothers reported in Japan were investigated and compared with cases reported from other countries.

RESULTS

Japanese cases were highly associated with anti-SS-A/Ro, anti-SS-B/La, anti-ribonuclear protein, and anti-DNA antibodies. A low frequency of congenital heart block was noted but 8.3% of the cases progressed to systemic lupus erythematosus. HLA-DRw12 was a significantly relative risk in NLE.

CONCLUSION

The clinical characteristics of Japanese NLE patients were different from those of caucasian patients reported in the literature.

Anti-Ro/SS-A antibodies in the pathophysiology of congenital heart block in neonatal lupus syndrome, an experimental model. In vitro electrophysiologic and immunocytochemical studies

OBJECTIVE

To determine whether anti-Ro/SS-A antibodies selectively bind to neonatal cardiac cells and alter membrane repolarization.

METHODS

An in vitro electrophysiologic and immunocytochemical experimental model contrasting neonatal and rabbit cardiac tissue was employed.

RESULTS

Sera and IgG-enriched fractions from anti-Ro/SS-A antibody-positive mothers of infants with neonatal lupus erythematosus and congenital heart block bind to neonatal, rather than adult, rabbit cardiac tissue and alter the transmembrane action potential (i.e., inhibit repolarization). The additional presence of anti-La/SS-B antibodies was not additive or synergistic for these immunocytochemical and electrophysiologic features. Sera containing other antibody specificities (i.e., anti-native DNA, cardiolipin, Sm, and nuclear RNP) failed to stain the neonatal cardiac tissue or produced alterations in membrane repolarization.

CONCLUSION

Anti-Ro/SS-A antibodies may play a pathophysiologic role in the development of congenital heart block in neonatal lupus.

The genetic basis of Ro and La antibody formation in systemic lupus erythematosus. Results of a multicenter study. The SLE Study Group

Antibodies against Ro and La, including recombinant La and recombinant 60 kD-Ro, were determined by counter immunoelectrophoresis and ELISA in over 300 central European systemic lupus erythematosus (SLE) patients. The presence of both Ro and La antibodies was strongly associated with the MHC haplotype B8-C4AQ0-DR3-DQ2, the association being strongest for DR3. After exclusion of all B8-DR3 positive patients only DR3 positive patients still showed an increased incidence of Ro and La antibodies, suggesting DR3 as the primary association factor. High titers of La antibody, but not of 60 kD-Ro antibody, were also significantly associated with the presence of DR3. Other DR and DQ antigens or heterozygous DQ combinations were not significantly associated with Ro and La antibodies.

MHC associations of autoantibodies against recombinant Ro and La proteins in systemic lupus erythematosus. Results of a multicenter study. SLE Study Group

Antibodies against recombinant 52 kD-Ro, recombinant 60 kD-Ro and recombinant La protein were determined by ELISA in over 300 central European patients with systemic lupus erythematosus (SLE). A strong association with HLA-DR3 was found for antibodies against 52 kD-Ro and La, but not for recombinant 60 kD-Ro antibodies in the absence of antibodies against 52 kD-Ro or La. Ro/La negative SLE patients still showed an increased frequency of HLA-DR3 as compared to healthy controls. These results indicated that the preferential formation of Ro and La antibodies was not due to an unspecific stimulatory effect of HLA-DR3 but that the antibody response to certain defined proteins (52 kD-Ro and La) was influenced by MHC genes in SLE. Furthermore, the association of SLE with HLA-DR3 was independent of the effects of DR3 on the formation of 52 kD-Ro and La antibodies.

Annular erythema. A comparative study of Sjögren syndrome with subacute cutaneous lupus erythematosus

Annular erythema developed in 22 patients with Sjögren syndrome. Clinically, the annular erythema was subdivided into three forms: Sweet disease-like annular erythema with an elevated border (14 cases); subacute cutaneous lupus erythematosus (SCLE)-like marginally scaled erythema (5 cases); and papular erythema (3 cases). Histopathologically, features commonly seen in annular erythema are deep perivascular and/or periappendageal infiltration of the lymphocytes with an admixture of neutrophils or plasma cells and less frequent epidermal changes suggestive of cutaneous lupus erythematosus. Immunoglobulin or complement deposition along the dermoepidermal junction of lesional skin was observed in 8 of 18 cases, and most of the dermal infiltrates consisted of CD4(+), 4B4(+) cells. The appearance of anti-SS-A(Ro) (100%) and anti-SS-B(La) (77%) was significantly higher in patients with annular erythema. These results suggest that patients with Sjögren syndrome might have a distinct annular erythematous lesion that is both clinically and histopathologically different from SCLE, although close immunologic abnormalities exist in these two diseases.

Immunogenetic findings in cutaneous lupus erythematosus

The serologic features and histocompatibility antigen associations of 93 patients with cutaneous lupus erythematosus are reported. Of them, 37 had chronic cutaneous lupus erythematosus and 56 had subacute cutaneous lupus erythematosus. Subacute cutaneous lupus erythematosus with an annular pattern occurred in 32 patients; 24 had a papulosquamous morphology. Sixty percent of patients with annular subacute cutaneous lupus erythematosus had anti-Ro antibodies. The incidence of this antibody in the other two groups was lower. In addition, patients with annular skin lesions had significant antigen association with HLA-B8 (37.5%; relative risk, 4.6) and HLA-DR3 (59.4%; relative risk, 4.3). There were no significant differences among chronic cutaneous lupus erythematosus and subacute cutaneous lupus erythematosus of the papulosquamous type and the control population for any HLA loci. Thus only patients with annular skin lesions represent a homogeneous subgroup in which there is a striking concordance of anti-Ro antibodies and the HLA-B8 and HLA-DR3 phenotypes.

Subacute cutaneous lupus erythematosus-immunogenetic associations

Thirty-two patients who fulfilled criteria for subacute cutaneous lupus erythematosus (SCLE) were examined for their immunogenetic associations. Our results confirm the previously reported association of HLA-DR3 (15/31 48% P less than 0.01) and also demonstrate an increase in HLA-DR2 (14/31, 45%, P = less than 0.05). These findings indicate there are two distinct immunogenetic (HLA) populations of Ro(SS-A) antibody-positive SCLE patients. The increased frequency of HLA-DR2 and DR3 appears to be associated with expression of the Ro(SS-A) antibody, since no HLA associations were seen in Ro(SS-A)-negative SCLE patients when compared with normal population controls. Furthermore, these data indicate that the distinctive cutaneous lesions of SCLE are not associated with one specific HLA allele, as previously suspected. These findings contrast with the relatively homogeneous immunogenetic background seen in other lupus erythematosus subsets with a high frequency of Ro(SS-A) antibody, i.e., neonatal lupus erythematosus and Sjögren's syndrome/lupus erythematosus overlap (increased frequency of HLA-DR3, DQw2 and DRW52).

ICAM-1 and LFA-1 expressions in the lesional skin of annular erythema associated with Sjögren syndrome

ICAM-1 and LFA-1 expression was studied in the lesional skin of ten cases of annular erythema associated with Sjögren syndrome. Most of the infiltrating mononuclear cells around blood vessels expressed LFA-1 in addition to its strong expression on vascular endothelial cells and focal expression on the epidermal basal cell layer in 3 cases. ICAM-1 expression on vascular endothelial cells was similar to LFA-1, although relatively focal and weak expression was observed on mononuclear cells. ICAM-1 expression on keratinocytes was focal and limited to the basal cell layer in annular erythema. These findings suggest that strong expression of ICAM-1 on endothelial cells but not keratinocytes and LFA-1 on mononuclear cells might play some role in the induction of skin lesions in annular erythema associated with Sjögren syndrome.

Epidermal cell surface-associated IgG in patients with primary Sjögren's syndrome: in vitro evidence for immune complex binding

In vivo deposits of IgG have previously been demonstrated in the epidermal intercellular area of clinically unaffected skin from 68% of patients with primary Sjögren's syndrome (primary SS). This study compared circulating IgG from patients with primary SS with that from secondary SS in their ability to bind normal human epidermal cells in vitro. We observed a granular pattern of IgG binding to the normal epidermal cell surfaces with 9 of 18 sera from patients with primary SS (50%), 3 of 19 sera from patients with SS secondary to rheumatoid arthritis (16%) (p = 0.025), and none of 24 normal control sera (p less than 0.001). In a subsequent analysis of polyethylene glycol separated sera from two normal controls and two primary SS patients, the epidermal IgG binding capacity was found only in the precipitates of the patients. These findings support our previous hypothesis that the in vivo intraepithelial IgG deposits in primary SS patients are due, at least in part, to cell surface-bound immune complexes.