Sessa A, Meroni M, Battini G (eds): Systemic Lupus erythematosus: Renal Vaseulitis. Contrib Nephrol. Basel, Karger, 1992, vol 99, pp 9498 Antineutrophil Cytoplasmic Antibodies in Systemic Lupus erythematosus Sonj Küster, Susnne Apenberg, Konrd Andrssy, Eberhrd Ritz Department of Internal Medicine, University of Heidelberg, FRG The characteristics of lupus serology and their relation to the course of disease have been established for a long time. With the recent introduction of antineutrophil cytoplasmic antibodies [1], it has become apparent, however, that some lupus patients have ANCA antibodies [2]. Further characteristics of the epitopes involved and a correlation of such antibodies to the clinical course of the disease have not been thoroughly investigated. This prompted the present analysis, in part retrospective, on all consecutive 44 patients with systemic lupus erythematosus (SLE) who had been admitted to the Renal Division of the Department of Internal Medicine, Heidelberg, for evaluation. Ptients The main patient data are summarized in table 1. Dermal vasculitis was defined as palpable purpura or leukocytoclastic vasculitis on skin biopsy. Of the 34 patients with renal involvement (12/34 of whom had elevated serum creatinine), 23 had a renal biopsy. Crescents were found in a total of 9 patients. The respective diagnoses were mesangial proliferative GN (n = 8, 1 with crescents), membranous GN (n = 7, 3 with crescents), membranoproliferative GN (n = 4, 1 with crescents), and crescentic necrotizing GN (n = 4). In the the patients with crescentic GN, elevated serum creatinine was found in 3 of 9 and transient dialysis was necessary in 2 patients. Serology was obtained at the time of admission which did not coincide with immunosuppressive treatment in all patients. Serology Techniques

Antineutrophil Cytoplasmic Antibodies in SLE 95 Table 1. Patient data

Downloaded by: National Univ. of Singapore - 3/27/2017 5:19:41 AM

ANA, ds-DNA, complement, and thyroid microsomal antibodies (hemagglutination inhibition) were measured with standard methods as published elsewhere [3]. SSA (Ro) and SSB (La) antibodies were identified with counter immunoelectrophoresis using an EBVinfected immortalized WIL-2 cell line [4]. ANCA were investigated by immunofluorescence

(c-ANCA; p-ANCA) and by ELISA against the 29-kD antigen (=proteinase-3) according to Rasmussen et al. [5] and against myeloperoxidase as published elsewhere [6]. Lactoferrin antibodies were determined using a newly developed ELISA. In brief, microtiter plates were coated with lactoferrin (Calbiochem; 5 µg/ml in carbonate buffer, pH 9.6 for 48 h at 4 °C). After incubation with samples and reference sera, IgG was detected using alkaline phosphatase labelled antihuman IgG (Sigma). Para-nitrophenyl phosphate (Sigma Company) was used as substrate and absorbance was read at 405 nm substracting the background extinction of ELISA plates at 620 nm on an ELISA reader. The presence of lactoferrin antibodies in the reference sera was confirmed by immunoblotting against a monoclonal lactoferrin antibody. Findings nd Discussion As shown in table 2, the prevalence and titers of ds-DNA ab, but not of ANA, were higher in patients with renal involvement. The band test, í.e. immunofluorescence (IF) of skin biopsies of noninvolved sunexposed skin, was positive in some patients and was valuable for the diagnosis in ANA-negative patients with glomerulonephritis. Complement concentrations (not all at the beginning of renal symptomatology) were not different between the two groups. SSA (Ro) and SSB (La) Table 2. Lupus serology Küster/Apenberg/Andrassy/Ritz 96

antibodies were found in a high proportion of patients with or without renal involvement. A surprisingly large proportion of patients had thyroid microsomal antibodies; cross-reaction of thyroid microsomal antibodies (which are directed against thyroid peroxidase) [7] and myeloperoxidase (see below) is unlikely since there was no correlation between the two tests. Table 3 shows that c-ANCA and 29-kD serine esterase ab were negative throughout. p-ANCA of variable IF pattern was positive in almost all patients, only a proportion of whom had low titer myeloperoxidase ab. Lactoferrin ab were noted only in one single patient. As shown in figure 1, the titers of MPO antibodies were lower than in patients with RPGN in the course of microscopic polyarteritis and were comparable to . Antineutrophil Cytoplasmic Antibodies in SLE 97

Downloaded by: National Univ. of Singapore - 3/27/2017 5:19:41 AM

Fig. 1. MPO antibodies in patients with RPGN, SLE, Schönlein-Henoch, Churg-Strauss and Goodpasture syndrome.

Table 3. ANCA serology One patient with dermal vasculitis and crescentic GN. the titers seen in Schönlein-Henoch purpura, Churg-Strauss syndrome and Goodpasture syndrome. As shown in table 4, of the 5 patients who had dermal vasculitis, all had MPO ab. Of the 9 patients with crescentic glomerulonephritis, 6 had MPO ab, in particular in all 4 patients with necrotizing crescentic GN MPO ab were positive. It appears then that MPO ab identify a subgroup of patients with more severe cutaneous vasculitis and/or crescentic glomerulonephritis, similar to what has recently been observed in Schönlein-Henoch syndrome [8] and Goodpasture syndrome [6]. However, we found no correlation with renal outcome, i.e. relation of MPO ab at presentation to serum creatinine at last evaluation. Conclusions While p-ANCA are almost consistently positive in SLE, low-titer MPO ab are present in one-quarter of the patients with severe SLE and appear to indicate the presence of dermal vasculitis and/or crescentic glomerulonephritis. Küster/Apenberg/Andrassy/Ritz 98

1 Falk R. Jennette J. Anti-neutrophil cytoplasmic autoantibodies with specificity for myeloperoxidase in patients with systemic vasculitis and idiopathic necrotizing and crescentic glomerulonephritis. N Engl J Med 1988;318:16511657. 2 Jennette J. Falk R: Antineutrophil cytoplasmic autoantibodies and associated diseases: review. Am J Kidney Dis 1990;XV:517529. 3 Andrassy K, Koderisch J. Rufer M, et al: Detection and clinical implication of anti-neutrophil-cytoplasm antibodies in Wegener's granulomatosis and rapidly progressive glomerulonephritis. Clin Nephrol 198932:159167. 4 Andrassy K, Gebest J, Tan . et al: Interstitial nephritis in a patient with atypical Sjögren's syndrome. klin Wochenschr 198058:563569. 5 Rasmussen . Sjöhn C, Issaksson B, et al: An ELISA for the detection of antineutrophil cytoplasm antibodies. J Immunol Methods 1990;127:139145. 6 Weber . Andrassy K, Pullig O, et al: Antineutrophil-cytoplasmic antibodies in Goodpasture's syndrome and anti-GBM antibodies in Wegener's granulomatosis. J Am Soc Nephrol 1992;2:12271234. 7 Mariotti S. Anelli S, Ruf J, et al: Comparison of serum thyroid microsomal and thyroid

Downloaded by: National Univ. of Singapore - 3/27/2017 5:19:41 AM


peroxidase autoantibodies in thyroid diseases. J Clin Endocrrnol Metab 1987;65:987 993. 8 Andrassy K, Koderisch J, Adler D: Diagnostische Bedeutung von neutrophilen zytoplasmatischen Antikörpern in der Nephrologie. Immun Infekt 1990;18:5355.

Downloaded by: National Univ. of Singapore - 3/27/2017 5:19:41 AM

Dr. Sonja Kúster, Departement Innere Medizin, Sektion Nephrologie, Bergheimer Strasse 56, D-W-6900 Heidelberg (FRG)

Antineutrophil cytoplasmic antibodies in systemic lupus erythematosus.

Sessa A, Meroni M, Battini G (eds): Systemic Lupus erythematosus: Renal Vaseulitis. Contrib Nephrol. Basel, Karger, 1992, vol 99, pp 9498 Antineutroph...
7KB Sizes 0 Downloads 0 Views