Antibodies to cytoplasmic antigens in lupus erythematosus. Serologic marker for systemic disease

Cutaneous lupus erythematosus: Reflecting on practice-changing observations over the past 50 years

Several historical observations have led to the current understanding of the diagnosis, evaluation, and management of patients with cutaneous lupus erythematosus. Seminal advances in the management of this disease include the development of a classification system for cutaneous lupus, the use of a validated scoring system to assess patient disease activity, and expansion of knowledge of the action spectrum of this disease; further, observations regarding certain medications as potential causes of subacute cutaneous lupus erythematosus, the risk of progression from "pure" cutaneous disease to systemic disease, and traditional versus newer therapies are reviewed with closer inspection.

Applying Choosing Wisely: Antinuclear Antibody (ANA) and Sub-Serology Testing in a Safety Net Hospital System

Objective:

In 2013, the American College of Rheumatology (ACR) participated in the Choosing Wisely campaign and devised a recommendation to avoid testing antinuclear antibody (ANA) subserologies without a positive ANA and clinical suspicion of disease. The goals of our study were to describe ANA and subserology ordering practices and predictors of ordering concurrent ANA and subserologies in a safety-net hospital.

Methods:

We identified ANA and subserologies (dsDNA, Sm, RNP, SSA, SSB, Scl-70 and centromere) completed at Denver Health between 1/1/2005 and 12/31/2011. Variables included demographics, primary insurance, service, and setting from which the test was ordered. We performed multivariable logistic regression to determine predictors of concurrent ordering of ANA and subserologies.

Results:

During seven years, 3221 ANA were performed in 2771 individuals and 211 (6.6%) were performed concurrently with at least one subserology. The most common concurrent subserologies were dsDNA (21.8%), SSA (20.8%), and SSB (19.7%). In the multivariable logistic analysis, significant predictors of concurrent ANA and subserologies were the labs being ordered from subspecialty care (OR 8.12, 95% CI 5.27-12.50, p-value <0.0001) or from urgent/inpatient care (OR 3.86, 95% CI 1.78-8.38, p-value 0.001). A significant predictor of decreased odds was male gender (OR 0.32, 95% CI 0.21-0.49, p-value <0.0001). Five individuals (2.2% of the negative ANA with subserologies ordered) had a negative ANA but positive subserologies.

Conclusion:

Of 3221 ANA, 6.6% were performed concurrently with subserologies, and subspecialists were more likely to order concurrent tests. A negative ANA predicted negative subserologies with rare exceptions, which validates the ACR’s recommendations.

A model for lupus brain disease

Systemic lupus erythematosus is an autoimmune disease characterized by antibodies that bind target autoantigens in multiple organs in the body. In peripheral organs, immune complexes engage the complement cascade, recruiting blood-borne inflammatory cells and initiating tissue inflammation. Immune complex-mediated activation of Fc receptors on infiltrating blood-borne cells and tissue resident cells amplifies an inflammatory cascade with resulting damage to tissue function, ultimately leading to tissue destruction. This pathophysiology appears to explain tissue injury throughout the body, except in the central nervous system. This review addresses a paradigm we have developed for autoantibody-mediated brain damage. This paradigm suggests that antibody-mediated brain disease does not depend on immune complex formation but rather on antibody-mediated alterations in neuronal activation and survival. Moreover, antibodies only access brain tissue when blood-brain barrier integrity is impaired, leading to a lack of concurrence of brain disease and tissue injury in other organs. We discuss the implications of this model for lupus and for identifying other antibodies that may contribute to brain disease.

Antinuclear antibody-negative systemic lupus erythematosus in a case with pregnancy

We described a 30-year-old pregnant woman developing antinuclear antibodies (ANA)-negative systemic lupus erythematosus (SLE) accompanied with arthritis, malar rash, lymphopenia, autoimmune hemolytic anemia, pericardial and pleural effusion, proteinuria and seizures. All serum autoantibodies except anti-Ro antibody were negative. An artificially induced abortion was performed to prevent SLE deterioration. Steroid and cyclophosphamide therapy were effective for this patient. During the 2-year follow-up period, her ANA and other SLE-related autoantibodies in serum remained negative. This case suggests that ANA may not be required in the pathogenesis of SLE, even in the case with pregnancy, and ANA-negative SLE may also have a dangerous clinical course.

An antinuclear antibody-negative patient with lupus nephritis

Systemic lupus erythematosus (SLE) is a typical autoimmune disease that's characterized by various autoantibodies to nuclear and cytoplasmic antigens. The presence of antinuclear antibodies (ANA) in serum is generally considered a decisive diagnostic sign of SLE. However, a small subset of SLE patients who had the typical clinical features of SLE was reported to show persistently negative ANA tests. Our report describes a 16-yr-old female who presented with the clinical manifestations of SLE such as malar rash, photosensitivity, arthritis, lymphopenia, pericarditis and proteinuria. The serum autoantibodies were all negative and renal biopsy showed that the histopathological changes of immune complex mediated the focal segmental necrotizing glomerulonephritis with crescent formation. She was treated with monthly pulse cyclophosphamide along with corticosteroids. During the 2-yr follow-up period, the proteinuria was markedly decreased and all of the ANA and anti-double stranded DNA antibody tests were negative. This case suggests that ANA may not be required in the pathogenesis of lupus nephritis.

Evaluation of multiplexed fluorescent microsphere immunoassay for detection of autoantibodies to nuclear antigens

Antibodies to extractable nuclear antigens (ENA) are found in a variety of collagen vascular diseases. Determining the individual specificities of these antibodies is extremely useful in establishing the disease diagnosis and in some cases the prognosis. With a multiplexed fluorescent microsphere immunoassay, reactivity to five of the most diagnostically useful ENA was measured in 249 serum samples, including samples from 56 patients previously documented to have systemic lupus erythematosus (SLE). Results of the multiplexed assay were compared to results from established ENA enzyme-linked immunosorbent assays (ELISAs), and the agreement, sensitivity, and specificity, respectively, for the five ENA evaluated were as follows: SSA, 99.1, 100.0, and 98.8%; SSB, 98.6, 88.9, and 99.5%; Sm, 97.6, 95.8, and 97.9%; RNP, 97.2, 92.7, and 98.8%; Scl-70, 93.6, 50.0, and 99.0%. In the 56 confirmed SLE patients, the frequency of significant concentrations of autoantibodies with the multiplexed assay was 21.4% for SSA, 7.1% for SSB, 10.7% for Sm, 32.1% for RNP, and 0% for Scl-70. The new flow cytometric bead-based multiplexed assay showed excellent correlation with the well-established single-analyte ELISA methods for four of five the ENA markers investigated in this study. The most notable discrepancies between the two assays were for the Scl-70 antigen, which was most often resolved in favor of the multiplexed assay. Our studies show that the multiplexed microsphere-based immunoassay is a sensitive and specific method for the detection and semiquantitation of ENA antibodies in human sera.

Antinuclear antibody-negative systemic lupus erythematosus: revisited

Systemic lupus erythematosus is a chronic multisystem disorder characterized by the presence of distinctive

ANA negative systemic lupus erythematosus sera revisited serologically

OBJECTIVE

To better define the serology of a panel of sera from patients with a clinical diagnosis of systemic lupus erythematosus (SLE) or subacute cutaneous lupus erythematosus (SCLE) with a negative antinuclear antibody (ANA) test on mouse liver.

METHODS

Sensitive ELISA methods for anti-Ro/SSA, anti-La/SSB, and anti-U1RNP were applied to a panel of 76 sera with either SLE or SCLE and a negative ANA test on mouse liver.

RESULTS

These sera had previously been shown to have a high prevalence of anti-Ro/SSA (68%) and anti-La/SSB (27%) precipitins respectively. None had precipitins to U1RNP or Sm. ELISA methodology revealed that all of the sera 76/76 (100%) had elevated levels (> mean +/- 2 SD of a panel of 21 normal sera) of anti-Ro/SSA, 36/76 (46%) had elevated levels of anti-La/SSB, and 27 of 76 (35%) had elevated levels of anti-U1RNP.

CONCLUSION

The subset of patients with SLE and SCLE with a negative ANA test on mouse liver almost uniformly have antibodies to the Ro/SSA antigen by a sensitive ELISA. This adds evidence to the idea that this is a more homogeneous disease subset within the spectrum of SLE.

Significance of the anti-Ro (SS-A) antibody in evaluation of patients with cutaneous manifestations of a connective tissue disease

The anti-Ro(SS-A) antibody is arguably the most important antibody determination except for antinuclear antibodies in evaluation of patients suspected of having lupus erythematosus. During the past 25 years, studies have established the importance of this antibody in the evaluation of patients with atypical lupus erythematosus, who have a photosensitive dermatitis as the presenting sign. The purpose of this review is to demonstrate the utility and the necessity of this antibody determination in the evaluation of all patients with cutaneous manifestations who are suspected of having a connective tissue disease.

Impact of ultraviolet irradiation on expression of SSA/Ro autoantigenic polypeptides in transformed human epidermal keratinocytes

SSA/Ro autoantibodies are frequently found in various autoimmune disorders including subacute cutaneous and neonatal lupus erythematosus. SSA/Ro patient sera precipitate a ribonucleoprotein complex consisting of multiple polypeptides and small RNA molecules (hY RNA). Such sera react in Western blot with at least four antigenically distinct proteins having molecular weights of 52-60 kD. Several laboratories have reported increased binding of anti-SSA/Ro patient serum to viable cultured human epidermal keratinocytes following UVB irradiation. However, it is currently unknown which SSA/Ro molecule(s) might be responsible for this increased antibody binding to UVB irradiated keratinocytes. To address this question, we studied the effect of UVB irradiation on the expression of three different polypeptide components of the SSA/Roautoantigen complex (60 kD SSA/Ro, 52 kD SSA/Ro, and 46 kD SSA/Ro (calreticulin) in A431 cells, a transformed human epidermal keratinocytes cell line. Total cellular and cell surface expression of each SSA/Ro antigenic polypeptide was examined by a whole cell ELISA and FACS using rabbit anti-synthetic peptide antisera as probes. Our results suggest that both total cellular and cell surface calreticulin, but not the 60 and 52 kD SSA/Ro polypeptides, is increased after 100 J/M2 of UVB irradiation, indicating that perturbed calreticulin expression may be primarily responsible for the UVB-induced increased binding of anti-SSA/Ro to keratinocytes. These results suggest that calreticulin could be a critical component of the SSA/Ro ribonucleoprotein complex that is involved in the pathogenesis of anti-SSA/Ro-associated photosensitive LE skin lesions.

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.

Prevalence of acne rosacea in a rheumatic skin disease subspecialty clinic

There are many causes of malar erythema besides the classic butterfly rash of acute cutaneous lupus erythematosus (LE). Twenty-one patients (6.7% of new patient visits) referred to a dermatology department-based rheumatic skin disease subspecialty clinic over a 5-year period in whom a diagnosis of cutaneous LE had been entertained were found to have diagnoses other than autoimmune connective tissue diseases. Sixteen of the patients in this cohort (76%) had acne rosacea (rosacea), while the remaining five had other dermatologic disorders. Review of their records revealed that upon referral nine of these 21 patients (43%) had positive antinuclear antibody (ANA) assays, most with insignificant or marginal titers by our laboratory standards. On repeat ANA testing in our laboratory, all of these patients had insignificant ANA titers. Physicians may be giving too much weight to low-titer ANAs in assessing patients with isolated malar erythema. These issues are discussed in the overall context of the differential diagnosis of malar erythema. A simple punch skin biopsy can be very helpful in distinguishing cutaneous LE from other causes of malar erythema.

Development of a solid phase enzyme immunoassay for the detection of anti-Ro autoantibodies

An enzyme immunoassay was developed to detect anti-Ro(SS-A) autoantibodies. Both Ro-antigen components (52 and 60 kD) were purified from a pig spleen extract, using fast protein liquid chromatography (FPLC). Anti-La, anti-RNP, anti-DNA and anti-Sm antibodies do not react to the purified antigen. There was a strong correlation between anti-Ro activity in EIA and the titers in counter immunoelectrophoresis (rs = 0.893). Anti-Ro antibodies were found in 54 (69.2%) of 78 SLE sera by the developed EIA.

Importance of detection of SS-A/Ro autoantibody in screening immunofluorescence tests for autoantibodies to nuclear antigens

SS-A/Ro autoantibodies are related to Sjögren's syndrome and to several clinical subsets of lupus erythematosus. The most widely used laboratory procedure for ANA screening is the indirect immunofluorescence test (IF-ANA); the laboratory detection of anti-SS-A/Ro requires implementation and adherence to several technical and quality assurance recommendations. Using appropriate substrate cells containing the SS-A/Ro antigen, many so-called "ANA-negative" lupus erythematosus patients will demonstrate a positive IF-ANA.

Detection of anti-nuclear antibodies from patients with systemic rheumatic diseases by ELISA using HEp-2 cell nuclei

A microtiter plate was coated with cell nuclei from HEp-2 cells, and the stabilized nuclei were fixed with acetone for an enzyme-linked immunosorbent assay (ELISA). Autoantibodies against nuclear antigens were detected from the sera of patients with various systemic rheumatic disease but not from healthy individuals by means of the nucleus ELISA procedure. Ninety-one percent of antinuclear antibody (ANA)-positive sera as demonstrated by immunofluorescence (IF) test were also judged as positive for ANAs by the nucleus ELISA and 5% of them as pseudo-positive. Patient's sera with homogeneous and fine-speckled IF patterns displayed the highest ELISA titers. A large portion of ss-A/Ro antigen is localized in the cytoplasm; therefore, anti-ss-A/Ro antibody was hardly detected by nucleus ELISA. The population of ANAs detectable by nucleus ELISA included anti-ss-B/La, anti-DNA, anti-histone, anti-Sm, anti-RNP, and anti-scl-70.

Clinical associations of antiribonucleoprotein antibodies in patients with systemic lupus erythematosus

The authors undertook a cross-sectional study to investigate the clinical associations of antiribonucleoprotein (anti-RNP) antibodies in 49 patients with systemic lupus erythematosus (SLE) without other concomitant connective tissue disorders. The traditional counterimmunoelectrophoresis (CIE) and the immunoblotting (IB) technique were compared. Clinically, special attention was given to the identification of sclerodermalike features. All patients completed a detailed questionnaire, physical examination, and additional investigations including pulmonary function tests, chest roentgenogram, radionuclide transit studies of the esophagus, and nailfold capillary microscopy. Pulmonary function testing and radionuclide transit studies of the esophagus were very sensitive for the detection of (subclinical) pulmonary and esophageal involvement, respectively. Within the relatively homogeneous SLE population, a subset was recognized that was characterized clinically by the presence of sclerodermalike features such as Raynaud's phenomenon, sclerodactyly, interstitial changes on chest roentgenogram, and decreased numbers of nailfold capillary loops, and serologically by the presence of anti-RNP antibodies. IB was somewhat more sensitive than CIE for the detection of anti-RNP (anti-Sm/anti-nRNP) antibodies but did not identify other clinical associations. Thus, anti-RNP antibodies in SLE are associated with scleroderma-associated features. For clinical practice, CIE is the technique recommended for their detection.

Subacute cutaneous lupus erythematosus in Iceland

Identification of patients with subacute cutaneous lupus erythematosus (SCLE) in Iceland was performed by means of a survey based on the histopathologic or immunofluorescent diagnosis of lupus erythematosus. Respondents underwent serologic studies, gave histories, and, dependent upon the latter, were examined. The resultant proportional rate of patients with SCLE approached 10% of all lupus erythematosus cases.

Interstitial pneumonitis in antinuclear antibody-negative systemic lupus erythematosus: a new clinical manifestation and possible association with anti-Ro (SS-A) antibodies

The clinical manifestations of patients with systemic lupus erythematosus (SLE) and negative fluorescent antinuclear antibody have been well documented. This report describes 2 cases of antinuclear antibody-negative SLE with antibodies only to Ro (SS-A) and the previously unreported clinical manifestation of lupus interstitial pneumonitis. A review of all SLE patients from 1984-1986 with interstitial pneumonitis revealed that 10 of the 12 patients had antibodies to Ro (SS-A). The frequency of anti-Ro (SS-A) with interstitial pneumonitis in SLE patients suggests a possible association between the two.

SSA/Ro antigen expression in simian virus 40-transformed human keratinocytes

SSA/Ro antigen is a soluble cellular component to which antibodies are frequently produced in patients with Sjögren's syndrome and systemic lupus erythematosus. Its exact location within the cell has yet to be determined. In this study we report the expression of SSA/Ro antigen in simian virus 40 (SV40)-transformed keratinocytes. The locations of SSA/Ro, U1RNP, and DNA antigens were studied by indirect immunofluorescence using monospecific antibodies. SSA/Ro antigen was detected in both the nucleus and cytoplasm of SV40-transformed keratinocytes tested with three monospecific sera. Primary cultured keratinocytes derived from adult human skin showed localized immunofluorescent staining within the nucleus. When Ca++ concentration of the medium was switched to 0.05 mM, these cells expressed cytoplasmic SSA/Ro antigens within 48 h. Depletion of the antibody activity with insolubilized human spleen extract abolished the staining. Surface expression of this antigen could not be detected in either primary or transformed cells. Localization of U1RNP and DNA was not altered. These results indicate that expression of SSA/Ro antigen in human keratinocytes is modulated by SV40 infection and that this antigen is expressed to a greater degree in cells that are less differentiated, transformed, or proliferating.

Subacute cutaneous lupus erythematosus-like drug eruption due to combination diuretic hydrochlorothiazide and triamterene

Three patients taking a frequently prescribed diuretic combination of hydrochlorothiazide and triamterene developed eruptions resembling subacute cutaneous lupus erythematosus. Histopathology of the skin biopsies of all three patients was consistent with subacute cutaneous lupus erythematosus. On discontinuation of the diuretic drug, the cutaneous eruptions cleared.

Large speckle-like thready and thready antinuclear antibody patterns as markers for different clinical presentations in lupus erythematosus

Fifty-one patients with lupus erythematosus were studied retrospectively. They were chosen on the basis of their antinuclear antibody (ANA) immunofluorescent pattern. Only those with the thready or the large speckle-like thready patterns were studied. Autoantibody profiles consisting of ANA, anti-single-stranded deoxyribonucleic acid (ssDNA) antibody, and anti-extractable nuclear antigen (ENA) antibody determinations were obtained. The patients with the thready ANA pattern and anti-ENA (Sm) antibodies had a significantly higher incidence of pulmonary, joint, and renal involvement than the anti-ENA negative patients with the large speckle-like thready pattern. There was also a significantly higher incidence of Raynaud's phenomenon in patients with the thready pattern than in those with the large speckle-like thready pattern. Photosensitivity was seen significantly more frequently in the patients with the large speckle-like thready pattern than in those with the thready pattern.

Significance of the Ro antigen system

Knowledge about antibodies to the Ro/SSA and La/SSB antigens has expanded greatly. Recognition of these antibodies was probably achieved 25 years ago but their macromolecular structure, clinical associations, and genetic relationships have come to light only in the past 7 years. It seems clear that these antibodies have a special place in the nosology of SLE and SS and that in certain instances (e.g., neonatal LE) the antibodies play a direct pathogenic role, while in other circumstances (e.g., vasculitis, nephritis, SS) tissue damage might result from immune complex deposition on vascular structures. Certainly, the latter problems will be active areas of investigation in the coming years. If the pace of recent progress continues, many of the questions raised in this review should soon have clear answers.

Expression of Ro/SS-A antigen in human skin and heart

Using human sera monospecific for anti-Ro/SS-A antibodies in an indirect immunofluorescence assay, Ro/SS-A antigen was found to be present in nuclei of human fetal ectodermal cells and newborn epidermal keratinocytes, but not in adult epidermal keratinocytes. After in vitro cultivation, Ro/SS-A antigen was also found in the nuclei of adult skin explant outgrowth cells. The localization of Ro/SS-A in fetal heart could not be precisely determined (possibly nuclear and membrane). Extracts from fetal skin and heart contained Ro/SS-A antigen which is identical to the Ro/SS-A present in WiL2 cell extract. The molecular weight of Ro/SS-A antigenic peptide present in these extracts is around 60K.

Systemic lupus erythematosus: delineation of subpopulations by clinical, serologic, and T cell subset analysis

Patients with systemic lupus erythematosus (SLE) (n = 194) were analyzed for correlation of clinical features. In addition, the proportions of the two major T cell subsets were determined in 87 subjects. Two patient subgroups were discerned: one in which severe renal disease, leukopenia, and thrombocytopenia predominated, and a second in which sicca syndrome and involvement of the central nervous system, lungs and muscle occurred. The ratio of T helper/inducer to T suppressor/cytotoxic cells was reduced in the first group and increased in the second. We conclude that SLE does not comprise a single disease entity, but rather represents a number of syndromes with overlapping clinical features. The correlation of clinical symptoms with the proportions of circulating T cell subsets suggests that several immunologic mechanisms may underlie the various types of SLE.

Relationships between antinuclear and anti-Ro/SS-A antibodies in subacute cutaneous lupus erythematosus

A certain degree of confusion has arisen regarding the relationship between patients having subacute cutaneous lupus erythematosus (SCLE) and those with "antinuclear antibody-negative" systemic lupus erythematosus (ANA-negative SLE). One of the confusing issues relates to published differences in the autoimmune serologic findings of these two patient groups. In order to clarify this issue, we have screened the sera from thirty-seven patients with SCLE for the presence of fluorescent antinuclear antibodies (FANA) on two different substrates--human Hep-2 tissue culture cells and mouse kidney sections. In addition, these same sera were assayed for anti-Ro/SS-A precipitin antibodies. Seventy-eight percent of the sera were FANA-positive at a titer of 1:10 or greater when tested on human Hep-2 cells, whereas 76% were positive at a titer of 1:80 or greater. Fifty-one percent were positive on mouse kidney sections at a titer of 1:10 or greater, whereas 46% were positive at a titer of 1:20 or greater. Twenty-two percent of these sera were completely FANA-negative on both human and mouse substrates. None of these sera that were negative on both substrates contained anti-Ro/SS-A antibodies. However, 69% of the sera that were FANA-positive on both human and mouse substrates were found to have detectable anti-Ro/SS-A antibodies. Ninety percent of the SCLE sera that were FANA-positive on human Hep-2 cells, but negative on mouse kidney sections, contained anti-Ro/SS-A antibodies. These sera gave a speckle-like, or particulate, nuclear immunofluorescence staining pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of RNP, Sm, and SS-A/Ro-specific antisera from patients with lupus erythematosus in inducing antibody-dependent cellular cytotoxicity (ADCC) of targets coated with nonhistone nuclear antigens

To better understand potential antibody-dependent mechanisms of tissue damage in lupus erythematosus (LE), an examination of whether antibodies to nonhistone nuclear antigens in LE patients' sera can induce ADCC of cellular targets coated with the corresponding antigens was undertaken. With high titer anti-RNP sera, significant ADCC was seen with monocyte (P less than 0.01), T-lymphocyte (P less than 0.001), and low-density lymphocyte (P less than 0.001) effectors. Using monocyte effectors, significant ADCC was seen with anti-RNP (P less than 0.01), anti-Sm (P less than 0.01), and anti-SSA/Ro (P less than 0.01), with the most profound lysis being with the anti-SSA/Ro sera. Neutrophils were ineffective in any nuclear antigen-antibody system tested. The effective mononuclear cell-mediated ADCC seen with anti-RNP, anti-Sm, and anti-SSA antisera may be related to the mononuclear cell-associated tissue change seen in cutaneous lupus lesions.

The significance of thrombocytopenia in systemic lupus erythematosus

The significance of thrombocytopenia in systemic lupus erythematosus (SLE) is unclear. Some researchers have found it associated with severe disease, others with mild disease. Thrombocytopenia (platelets less than 100,000) occurred in 21 patients seen at an SLE clinic over 18 months. Prospective assessment of 19 (non-SLE causes excluded) revealed 2 distinct subgroups. Seven were thrombocytopenic only during severe multisystem flares. Twelve had chronic thrombocytopenia with intermittent mild flares in other systems. Serious bleeding was rare in both subgroups. It was concluded that thrombocytopenia clearly is not a prognostic indicator.

Antinuclear and anticytoplasmic antibodies. Concepts and misconceptions

Skin involvement is a common feature of several diseases in which circulating autoantibodies to nuclear and cytoplasmic antigens can be found. Patients with these diseases can be managed more efficiently if the physician is fully aware of the diagnostic and prognostic value of these various antinuclear and anticytoplasmic antibodies. The dermatologist, therefore, not infrequently, must face the bewildering task of ordering and interpreting the results of assays for an ever-increasing number of circulating autoantibodies. In this report, we have attempted to make this less burdensome for the clinician by pointing out the basis for some of the confusion that has arisen in this area. The confusion has resulted primarily from a failure to recognize the limitations of the various assays involved.

Neonatal lupus syndrome in successive pregnancies

Two female siblings, born 15 months apart, developed neonatal lupus syndrome. Both had cutaneous lupus erythematosus (LE) lesions resolving with telangiectasis. Their cutaneous lesions were temporally related to transplacental passage of anti-SS-A (Ro) autoantibodies from their asymptomatic mother. Infants with this transient collagen vascular syndrome may have LE skin lesions, congenital heart block, and liver or hematologic abnormalities, and are possibly at risk for developing systemic lupus erythematosus (SLE) later in life. It is important to recognize that this syndrome may occur in successive pregnancies.

Anticytoplasmic antibodies in antinuclear antibody-negative lupus erythematosus. Correlation with clinical course

A patient with clinical manifestations of systemic lupus erythematosus (SLE) and without antinuclear antibodies was found to have anticytoplasmic antibodies. These anticytoplasmic antibodies were directed against ribosomal ribonucleoprotein, and the titer of anticytoplasmic and anti-ribosomal ribonucleoprotein antibodies correlated with the clinical course of the patient's illness. The importance of detecting anticytoplasmic antibodies and their role in producing disease in patients with SLE is discussed.

Serologic profiles as immunologic markers for different clinical presentations of lupus erythematosus

The clinical and laboratory features of 55 patients with lupus erythematosus (LE), grouped on the basis of six nuclear immunofluorescent pattern results commonly encountered in this disease were examined. Serologic profiles of antinuclear antibodies (ANA), anti-DNA and anti-ENA results can serve as immunologic markers in LE for a benign subset and two other groups with a different incidence of certain clinical characteristics. The large speckle-like thready pattern without antibodies to DNA or ENA is an immunologic marker for a benign LE subset, with generalized skin lesions with or without joint involvement only. Significant levels of the anti-DNA antibodies with the shrunken peripheral, peripheral, or leukocyte-specific ANA with a particulate pattern are markers for severe systemic involvement. The thready pattern with antibodies to ENA (Sm antigen) and leukocyte-specific ANA without a particulate pattern, with or without antibodies to DNA or ENA, indicate less severe systemic disease.

Clinical and biologic significance of antibodies to Ro/SSA

Study of the clinical associations of antibodies to the soluble antigens Ro/SSA and La/SSB leads to several conclusions. Production of such antibodies are linked to the D locus antigens DR2 and DR3, suggesting involvement of disease susceptibility or immune response genes in the regulation of their synthesis. Genetics therefore provides one of the factors that contribute to the disease expression and the clinical heterogeneity that characterize systemic lupus erythematosus (SLE). The uniform presence of anti-Ro/SSA in neonatal lupus and the almost uniform presence of these antibodies in the vasculitis of Sjögren's syndrome suggest the participation of these antibodies in the immunopathogenesis of these particular clinical manifestations. Finally, identification of the molecular nature of these antigens as RNA-protein conjugates and the ability of the antibodies to La/SSB to bind viral-specific RNA-protein conjugates provide clues that may lead to elucidation of etiologic events in the development of SLE.

Antinuclear antibody determinations in Ro(SSA)-positive, antinuclear antibody--negative lupus and Sjögren's syndrome patients

Antinuclear antibody determinations were performed on the sera of twenty-eight Ro(SSA)-positive patients, who failed to demonstrate significant antinuclear antibody titers on mouse liver, with the use of various heterologous and homologous substrates. These studies demonstrated the following: (1) The existence of substrate specificity among various tissues and cells employed in the detection of antinuclear antibodies in Ro(SSA)-positive patients. (2) The existence of a significant group of Ro(SSA)-positive lupus patients with prominent cutaneous findings and systemic disease who, despite the employment of a variety of antinuclear substrates, failed to demonstrate significant antinuclear antibody titer.

Relationship of clinical findings in systemic lupus erythematosus to seroreactivity

We have characterized 52 consecutive patients fulfilling 4 or more of the American Rheumatism Association criteria for systemic lupus erythematosus in order to provide, for the first time, a homogeneous sample for statistical comparison of antinuclear antibody (ANA)-positive and ANA-negative groups. Ten patients (19%) were seronegative. There was no significant difference in age, disease activity, organ system involvement, erythrocyte sedimentation rate, immune complex levels, or C3 levels. The ANA-negative group showed a higher incidence of involvement for whites and men. Leukopenia, lower levels of antibody to DNA, and higher C4 levels were also characteristic of the ANA-negative group.