Antibodies to endothelial cells and to beta 2-glycoprotein I in the antiphospholipid syndrome: prevalence and isotype distribution

The aim of this study was to analyse the prevalence and isotype distribution of antibodies to endothelial cells (aEC) and to beta 2-glycoprotein I (a beta 2GPI) in the antiphospholipid syndrome (APS). Fifteen patients with an APS [nine associated with systemic lupus erythematosus (SLE) and six "primary'] and 15 with SLE without an APS were prospectively studied. The aEC were determined by an enzyme-linked immunosorbent assay (ELISA) using endothelial cells derived from human umbilical vein and the a beta 2GPI by ELISA using highly purified beta 2GPI. A positive titre of aEC was detected in 20 out of 30 patients (67%), but in none of the control group. Ten patients had both IgG and IgM isotypes, five had IgG only and five had only IgM. Thirteen patients with the APS (87%) were found to have a positive titre of aEC, while only seven with SLE but without a history of APS (47%) had aEC (P < 0.05). Nine patients with the APS (60%) had a positive titre of a beta 2GPI (four had both IgG and IgM isotypes, one had IgG only and four had only IgM), while none of the patients without an APS (0%) had these antibodies (P < 0.001). A significant association was also found between the presence of aPL and aEC (P < 0.05), as well as between aPL and a beta 2GPI (P < 0.001). Both aEC and a beta 2GPI can be found in the APS. This reinforces the theory that APS represents a complex autoimmune disorder in which several autoantibodies co-exist with aPL.

Intravenous immunoglobulin preceding in vitro fertilization-embryo transfer for patients with repeated failure of embryo transfer

OBJECTIVE

To determine the effectiveness of immunotherapy with high-dose IV immunoglobulin preceding IVF-ET for patients with repeated failure of ET.

DESIGN

Prospective, observational.

SETTING

Assisted Reproduction Unit of the Hospital Clínic i Provincial in Barcelona, a tertiary care setting.

PATIENTS

Twelve consecutive tubal infertility patients experiencing repeated unexplained IVF-ET failure including at least three ETs replacing three to four fresh embryos each. Two women shared three or more human leukocyte antigens (HLA) with the husband.

INTERVENTION

During the subsequent new IVF-ET cycle, each patient received 400 mg/kg IV immunoglobulin daily for 5 days during ovarian stimulation, that is, 5 to 7 days before ET.

MAIN OUTCOME MEASURES

Clinical pregnancies.

RESULTS

No implantation occurred. There were no side effects.

CONCLUSIONS

High-dose IV immunoglobulin is not a useful tool for IVF-ET failure.

Reduced serum creatine kinase activity in inflammatory rheumatic diseases

OBJECTIVE

To determine if serum CK activity is reduced in inflammatory rheumatic diseases and to evaluate whether this phenomenon is linked to disease activity or steroid therapy.

METHODS

Serum CK activity was measured in patients with systemic lupus erythematosus (SLE, n = 52), rheumatoid arthritis (RA, n = 80), ankylosing spondylitis (AS, n = 82), spondyloarthropathies other than AS (SpA, n = 22), and a miscellaneous group (MI, n = 27), and in 103 control patients with noninflammatory arthropathies (NIA). Laboratory variables of inflammatory activity such as ESR, CRP, platelet count, and hemoglobin (and anti-DNA antibodies and complement levels in SLE) were measured at the same time. Daily dose of steroids was also evaluated.

RESULTS

Serum CK activity was significantly reduced in SLE (mean +/- SD: 49 +/- 41 IU/l), RA (68 +/- 41 IU/l), SpA (88 +/- 53 IU/l), and MI (75 +/- 32 IU/l) compared to controls (111 +/- 38 IU/l) (p = 0.002 for SpA and p < 0.001 for the other groups). No differences in CK values were observed between AS and controls, although AS patients with peripheral arthritis had lower serum CK activity than those without (80 +/- 32 vs 121 +/- 62 IU/l, respectively, p < 0.05. ESR, CRP, and platelets correlated inversely with CK values in RA, AS, and MI. In the SpA group only ESR correlated inversely with CK. In SLE, a positive correlation was found between CK values and CH50 and a negative one with anti-DNA levels. Patients taking steroids had significantly lower CK activity than those without corticotherapy. However, multivariate analysis showed that only inflammatory activity and no steroids had an effect in reducing CK activity.

CONCLUSION

Serum CK activity is significantly reduced in several inflammatory rheumatic diseases. Inflammatory activity seems to play the major role in this phenomenon.

Prevalence and clinical significance of anticardiolipin antibodies in pregnancies complicated by parvovirus B19 infection

Anticardiolipin antibodies were measured in 60 pregnant women with acute parvovirus B19 infection. Test results for eight (13.3 per cent) women were positive for anticardiolipin antibody. Six of these eight women became negative later, yielding a prevalence of anticardiolipin antibodies of 3.3 per cent (2/60) 6 months after acute parvovirus B19 infection. Anticardiolipin antibody positivity was not associated with an increased risk of abortion, fetal death, or maternal complications. This study suggests that there is an elevated frequency of anticardiolipin antibodies in pregnant women with acute parvovirus B19, probably representing an epiphenomenon. However, this is not associated with an adverse maternal or perinatal outcome.

Development of polyarteritis nodosa in the course of inactive systemic lupus erythematosus

A 63-year-old woman developed a clinical and pathological picture of polyarteritis nodosa (PAN). Systemic lupus erythematosus (SLE) had been diagnosed 12 years previously, and she had been symptom and therapy-free for a decade. Development of 'primary' systemic vasculitis in SLE patients has rarely been described previously and the significance of this association remains unclear. The possible explanation for this transition from one connective tissue disease to another is discussed.

Occurrence of antineutrophil cytoplasmic and antineutrophil (peri)nuclear antibodies in rheumatoid arthritis

OBJECTIVE

To elucidate whether sera from patients with rheumatoid arthritis (RA) contain antineutrophil cytoplasmic antibodies (ANCA) or granulocyte specific antinuclear antibodies (GS ANA), or both, and to analyze possible correlations with different clinical and laboratory data.

METHODS

Forty-seven consecutive outpatients with RA were included. Control sera were obtained from patients with well defined rheumatic diseases and from healthy individuals. Serum samples were examined by indirect immunofluorescence (IIF) on both ethanol and paraformaldehyde fixed neutrophils and by ELISA using as substrates myeloperoxidase (MPO), proteinase 3, and a purified extract of alpha-granules. ANA were detected by IIF using cultured HEp-2 cells.

RESULTS

Twenty-three patients (49%) had a perinuclear pattern (p-ANCA) by ethanol fixation, of which only 2 became cytoplasmic on paraformaldehyde fixed cells. These 2 patients also had a positive myeloperoxidase ELISA, while none of the remaining 45 had a positive result from the 3 ELISA performed. All 21 patients (45%) with a p-ANCA pattern that was not modified by paraformaldehyde fixation had a specific immunostaining upon examination at high power magnification; we termed this GS ANA specific pattern. The specificity of this pattern was further confirmed by a doubled blind test performed by 2 independent observers. In our study, all GS ANA pattern positive sera fulfilled the previously known definition of these antibodies. We found no relationship between GS ANA and variables such as disease duration and activity, rheumatoid factor, and vasculitis. Notably, 2 RA patients with "true" ANCA (anti-MPO antibodies) had an associated pulmonary-renal syndrome (microscopic polyangiitis).

CONCLUSION

Most p-ANCA in our series of patients with RA did not seem to correspond to "true" ANCA but to antibodies directed against nuclear or perinuclear antigenic constituents of the neutrophils (GS ANA). The observation of their distinctive and specific immunostaining pattern, when screening patients for the presence of ANCA by IIF, may alert us to the possible presence of RA.

When does amyloidosis complicate systemic lupus erythematosus?

Secondary amyloidosis is a well recognised complication of rheumatic diseases, but the association with systemic lupus erythematosus is very unusual. We report the case of a patient with systemic lupus erythematosus who developed proteinuria due to renal amyloidosis. We also review the cases previously reported and the hypothesis on the pathogenic mechanisms.

The effect of systemic lupus erythematosus and long-term steroid therapy on bone mass in pre-menopausal women

The aim of our study was to assess bone mineral density (BMD) in pre-menopausal women with systemic lupus erythematosus (SLE) and the influence of disease activity and use of corticosteroids. Lumbar and femoral BMD were measured in 43 patients with SLE (28 on regular steroid therapy, 15 with recent onset, non-treated) and compared with 43 healthy women matched for age. In addition, 21 SLE patients treated with corticosteroids were followed-up with a mean of 36.6 +/- 12.7 months. BMD was significantly lower in SLE patients with prednisone doses > or = 7.5 mg/day than those of recent onset (lumbar: 1.07 +/- 0.11 vs 1.15 +/- 0.13, P = 0.039; femur: 0.85 +/- 0.13 vs 0.98 +/- 0.21, P = 0.034) and the control group (lumbar: 1.07 +/- 0.11 vs 1.13 +/- 0.10, P = 0.040; femur: 0.85 +/- 0.13 vs 0.93 +/- 0.10, P = 0.028). In addition, 18% of SLE steroid users had osteoporosis. Lumbar and femoral BMD were inversely correlated with the time of treatment and the cumulative doses of prednisone. There were no significant BMD changes during the 3-yr follow-up period. In conclusion, in SLE pre-menopausal patients lumbar and femoral BMD is decreased and related to long-term corticosteroid therapy.

Human epidermis reconstructed on synthetic membrane: influence of experimental conditions on terminal differentiation

Cell suspensions of human keratinocytes seeded onto cell culture inserts may undergo terminal differentiation in the absence of fibroblasts. Among the parameters that control these morphogenic events, exposure to air and the composition of the culture medium were investigated. In the latter case, three media were considered DMEM:Ham's F12, MCDB 153, and keratinocyte SFM medium at equivalent calcium (1.5 mM) and fetal calf serum (5%) concentrations. Immunochemical methods and transmission electron microscopy show that cells cultured in DMEM:Ham's F12 medium, and then raised at the air-liquid interface, form a basal layer plus suprabasal cell layers corresponding to the stratum spinosum, stratum granulosum, and stratum corneum. The suprabasal keratinocyte layers show morphologies that resemble intact skin in which cells are connected by desmosomes and contain intermediate filaments and keratohyalin-filaggrin granules. When the cultures are kept submerged, the keratinocytes show occasional keratohyalin granules and are connected by fewer desmosomes. Additionally, no proper stratum corneum is formed. In keratinocyte SFM medium and MCDB 153, cultures raised at the air-liquid interface are not able to form an epithelium of normal architecture and do not express terminal differentiation markers. Differentiation is initiated, however, since desmosomes and bundles of keratin filaments appear; on the other hand, filaggrin is not expressed even after 28 d in culture. Membrane-bound transglutaminase is expressed throughout the entire suprabasal compartment in MCDB153 and DMEM:Ham's F12 media but never appears in keratinocyte SFM medium. These studies show the relative independence of epidermal differentiation program to the composition (including the calcium concentration) of the media contacting the dermis and filling the extracellular space.(ABSTRACT TRUNCATED AT 250 WORDS)

Existence of a soluble form of CD50 (intercellular adhesion molecule-3) produced upon human lymphocyte activation. Present in normal human serum and levels are increased in the serum of systemic lupus erythematosus patients

CD50 (ICAM-3) is a leukocyte differentiation Ag expressed almost exclusively on hemopoietic cells, with a key role in the first steps of immune response. To develop a specific sandwich ELISA to detect a soluble CD50 form (sCD50), two different mAbs (140-11 and 101-1D2) recognizing non-overlapping epitopes were used. sCD50 was detected in the supernatant of stimulated PBMCs, with the highest levels after CD3 triggering. Simultaneously, the CD50 surface expression diminished during the first 24 h. sCD50 isolated from culture supernatant and analyzed by immunoblotting showed an apparent m.w. of 95 kDa, slightly smaller than the membrane form. These data, together with Northern blot kinetics analysis, suggest that sCD50 is cleaved from cell membrane. Furthermore, we detect sCD50 in normal human sera and higher levels in sera of systemic lupus erythematosus (SLE) patients, especially in those in active phase. The sCD50 levels showed a positive correlation with sCD27 levels (r = 0.4213; p = 0.0026). Detection of sCD50, both after in vitro CD3 triggering of PBMCs and increased in SLE sera, suggests that sCD50 could be used as a marker of lymphocyte stimulation.

Existence of a soluble form of CD50 (intercellular adhesion molecule-3) produced upon human lymphocyte activation. Present in normal human serum and levels are increased in the serum of systemic lupus erythematosus patients

CD50 (ICAM-3) is a leukocyte differentiation Ag expressed almost exclusively on hemopoietic cells, with a key role in the first steps of immune response. To develop a specific sandwich ELISA to detect a soluble CD50 form (sCD50), two different mAbs (140-11 and 101-1D2) recognizing non-overlapping epitopes were used. sCD50 was detected in the supernatant of stimulated PBMCs, with the highest levels after CD3 triggering. Simultaneously, the CD50 surface expression diminished during the first 24 h. sCD50 isolated from culture supernatant and analyzed by immunoblotting showed an apparent m.w. of 95 kDa, slightly smaller than the membrane form. These data, together with Northern blot kinetics analysis, suggest that sCD50 is cleaved from cell membrane. Furthermore, we detect sCD50 in normal human sera and higher levels in sera of systemic lupus erythematosus (SLE) patients, especially in those in active phase. The sCD50 levels showed a positive correlation with sCD27 levels (r = 0.4213; p = 0.0026). Detection of sCD50, both after in vitro CD3 triggering of PBMCs and increased in SLE sera, suggests that sCD50 could be used as a marker of lymphocyte stimulation.

Lack of relationship between human immunodeficiency virus infection and systemic lupus erythematosus

The objective of this work was to determine whether HIV-1 and HIV-2 could be involved in the pathogenesis of systemic lupus erythematosus (SLE). Seventy-five consecutive Caucasian patients with SLE presenting at one institution over a 2-year period were studied. Serum samples were surveyed for anti-HIV-1 antibodies by a commercial ELISA coated with HIV-1-p24. For confirmation, conventional immunoblots were performed with the following antigens: HIV-1-gp41, p31, p24 and p17 (recombinant) and HIV-2-gp36 (synthetic peptide). Additionally, Western blots with HIV-1-gp160, gp120, gp41, p65, p51, p24 and p18 bands were applied. Seventeen (23%) patients exhibited reactivity with HIV-1-p24 in the ELISA, but in the immunoblots and Western blots these sera samples were negative. Patients with SLE may exhibit a reactivity with HIV-1-p24 in the ELISA for HIV infection screening but not in the confirmatory blots. This false-positive reactivity is probably due to molecular mimicry between autoantigens and retroviruses or a contaminant or artefacts in the antigen preparation procedure.

A non-isotopic, highly sensitive, fluorimetric, cell-cell adhesion microplate assay using calcein AM-labeled lymphocytes

A simple and sensitive cell-cell adhesion microplate assay was established using the cytoplasmic fluorescent dye, calcein AM. The procedure involves three steps: the labeling of lymphocytes with an adequate concentration of calcein AM (20 microM) during a short incubation period (30 min); the adhesion of 2 x 10(5) labeled lymphocytes per well to confluent keratinocyte or fibroblast monolayers grown in microtiter plates for 90 min; and, finally, measurement of the fluorescent signal utilizing a new system of cold-light microfluorimetry (Rat, 1993). During the adhesion assay, the release of calcein from labeled lymphocytes is low and the method permits the detection of as few as 1000 adherent cells. This non-radioactive procedure takes less than 4 h to perform and has proven to be as accurate and reliable as the common method using radioactive isotopes. In addition to its simplicity, the use of a fluorescent molecular probe in conjunction with cold-light microfluorimetry (CLF) offers many advantages of safety and economy, and can readily be adapted to the different cell types that participate in cell-cell adhesion.

Effect of plasma from patients with primary antiphospholipid syndrome on platelet function in a collagen rich perfusion system

The effect on platelet function of plasma from 9 patients with primary antiphospholipid syndrome (PAS) with previous thrombotic episodes was investigated under flow conditions. Five asymptomatic individuals with antiphospholipid antibodies (aPL) (A-aPL) and 14 normal controls were also studied. Patients and controls plasmas were added (1:20 v/v) to anticoagulated blood and perfused through annular chambers containing collagen rich vessel segments. The interaction of platelets with vessel subendothelium was morphometrically evaluated in thin sections. An increase in both covered surface and thrombi formation was observed in perfusions in the presence of PAS-plasma (mean +/- SD: 34.2% +/- 9.6% and 23.2% +/- 10.0% respectively) compared with control plasmas (21.4% +/- 7.3% and 10.1% +/- 7.7%, p < 0.01). Affinity purified anticardiolipin antibodies from one PAS patient showed a similar effect when added to normal blood. In contrast, A-aPL plasma had no effect on platelet-subendothelium interaction. In parallel studies, the same plasmas were incubated with isolated normal platelets before and after activation with ADP or collagen and the binding of immunoglobulins (Ig) was determined by flow cytometry. A significantly increased binding of Ig was observed in 8 out of 9 plasmas from PAS patients when platelets had been activated with collagen but not when resting or ADP activated platelets were used. No increased Ig binding to platelets was seen using A-aPL individuals plasma. These observations might help to explain the pathophysiology of the thrombotic events occurring in patients with PAS.

Influence of fibroblasts on epidermization by keratinocytes cultured on synthetic porous membrane (insert) at the air-liquid interface

Culture of keratinocytes on a noncoated porous synthetic membrane maintained at the air-liquid interface allows the establishment of a fibroblast/keratinocyte co-culture, without direct cell-cell contact between the two cellular layers. The influence of fibroblasts (proliferating, confluent or blocked by mitomycin C) on epidermization (i.e., expression of integrins and markers of epidermal differentiation) was studied by immunohistochemistry in two culture media. In the medium supplemented with FCS or Ultroser G and in the absence of fibroblasts, alpha 2, alpha 3, alpha 5 and alpha 6 subunits of integrins are expressed by the basal keratinocytes, except alpha 5 which does not appear with the medium supplemented with Ultroser G. During stratification, the alpha 3 subunit is the only one to persist on suprabasal cells and all the markers of epidermal differentiation studied (filaggrin, involucrin, transglutaminase, keratins K1/K10) are expressed at the 14th day of emerged culture. The presence of fibroblasts modifies the expression profile of integrins: when they are proliferative, the expression of alpha 2 and alpha 6 chains is delayed in the medium supplemented with FCS, and the alpha 6 chain is absent in the medium supplemented with Ultroser G; when they are confluent or blocked by mitomycin C, greater changes are observed only in the medium supplemented with Ultroser G and lead to inhibition or delay of the expression of alpha 2 and alpha 6.(ABSTRACT TRUNCATED AT 250 WORDS)

A new three-dimensional culture of human keratinocytes: optimization of differentiation

Many attempts have been made to obtain reconstructed human epidermis comprised of keratinocytes and extracellular-matrix constituents (essentially collagen) in the presence or absence of fibroblasts. A simple model of cultured human keratinocytes, grown at the air-liquid interface of a noncoated artificial membrane, has been developed. This culture system offers many advantages: easy control of environmental factors and routine examination using optical or electronic microscopy, immunohistochemistry and indirect immunofluorescence techniques. This model enables the analysis of well-known differentiation markers and also integrins, a family of cell-surface molecules involved in cell-cell and cell-extracellular matrix interactions, whose receptors are expressed on all basal keratinocytes. In our culture system, the expression of the different integrin subunits (alpha 2, alpha 3, alpha 5, alpha 6, beta 1) was studied as a function of the differentiation state in two different media (K-SFM or DMEM/Ham's F12) supplemented with 5% fetal calf serum and adjusted to 1.5 mmol/L calcium. The most significant data are the preponderant expression of the alpha 2 and alpha 3 subunits in the basal and suprabasal layers, with membrane expression differing according to the culture medium; terminal differentiation was obtained in DMEM/Ham's F12. The use of membrane inserts represents a significant technological advance in culturing keratinocytes and is an easy-to-handle and valid model for determining the influence of physiological or pharmacological factors on cell proliferation or differentiation.