Massimo Drosera

Serology of Lupus Erythematosus: Correlation between Immunopathological Features and Clinical Aspects

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the aberrant production of a broad and heterogenous group of autoantibodies. Even though the presence of autoantibodies in SLE has been known, for more than 60 years, still nowadays a great effort is being made to understand the pathogenetic, diagnostic, and prognostic meaning of such autoantibodies. Antibodies to ds-DNA are useful for the diagnosis of SLE, to monitor the disease activity, and correlate with renal and central nervous involvements. Anti-Sm antibodies are highly specific for SLE. Anti-nucleosome antibodies are an excellent marker for SLE and good predictors of flares in quiescent lupus. Anti-histone antibodies characterize drug-induced lupus, while anti-SSA/Ro and anti-SSB/La antibodies are associated with neonatal lupus erythematosus and photosensitivity. Anti-ribosomal P antibodies play a role in neuropsychiatric lupus, but their association with clinical manifestations is still unclear. Anti-phospholipid antibodies are associated with the anti-phospholipid syndrome, cerebral vascular disease, and neuropsychiatric lupus. Anti-C1q antibodies amplify glomerular injury, and the elevation of their titers may predict renal flares. Anti-RNP antibodies are a marker of Sharps syndrome but can be found in SLE as well. Anti-PCNA antibodies are present in 5–10% of SLE patients especially those with arthritis and hypocomplementemia.

Antidesmoplakin antibodies in pemphigus vulgaris

Background  Besides being present in paraneoplastic pemphigus (PNP), circulating antidesmoplakin (DP) antibodies have been found anecdotally in other bullous diseases, including pemphigus foliaceus and pemphigus vulgaris.

Antihistone Antibodies in Scleroderma

BACKGROUND Antihistone antibodies (AHA) are usually considered the serological marker of drug-induced lupus erythematosus, but recently they have been found in patients with systemic scleroderma (SSc) and morphea. OBJECTIVE AND METHODS We determined AHA in 43 patients with SSc, 4 patients with overlap syndrome and 11 with morphea. RESULTS AND CONCLUSIONS AHA were demonstrated in 41.8% of the SSc patients and in 36.3% of the morphea patients. Only 1 patient with overlap syndrome had AHA. Our SSc patients with AHA had frequent cardiac and renal involvements suggesting a prognostic value of AHA. In our morphea patients AHA did not correlate with clinical features.

Frequency of IgA antibodies in pemphigus, bullous pemphigoid and mucous membrane pemphigoid.

Circulating and bound IgA antibodies can be found in the autoimmune blistering diseases, but their prevalence, clinical relevance and target antigens remain unknown. Thirty-two patients with pemphigus, 73 with bullous pemphigoid and 28 with mucous membrane pemphigoid were studied retrospectively. Direct immunofluorescence (DIF) analysis of IgG, IgA, IgM and C3 was carried out for all cases. Sera were studied by standard indirect immunofluorescence, indirect immunofluorescence on salt-split skin, immunoblotting for bullous pemphigoid and mucous membrane pemphigoid and ELISA for pemphigus. With DIF, we found IgA autoantibodies in 22 of all 133 cases. Circulating IgA antibodies to skin were detected in 2 of 3 IgA-DIF-positive patients with pemphigus, in 3 of 6 with bullous pemphigoid, and in 6 of 13 with mucous membrane pemphigoid. We confirm that the IgA reactivity is more frequently associated with mucous membrane involvement, especially in cases without critical involvement (5/8). The role of IgA and its antigenic specificity in these diseases remain unclear.

ACE inhibitors can induce circulating antibodies directed to antigens of the superficial epidermal cells.

Drug-induced pemphigus has been reported in patients receiving angiotensin-converting enzyme inhibitors. The aim of this work was to study a group of hypertensive patients without skin diseases treated with angiotensin-converting enzyme (ACE) Inhibitors (I), to verify the presence of serum circulating anti-antibodies. The indirect immunofluorescence showed that 33 sera (52.38%) presented autoantibodies directed to an antigen of the cytoplasm of the superficial epidermal keratinocytes. Two of the 33 positive sera had antibodies to Dsg1 and/or 3 in ELISA. Immunoblot analyses were negative. All the 48 control sera were found to have no circulating antibodies using the three assays. Our results would confirm that ACEI drugs may trigger the production of circulating autoantibodies also in patients without clinical manifestations of pemphigus.

Fosinopril as a Possible Pemphigus-Inducing Drug

Fosinopril has recently been added to the angiotensin-converting enzyme inhibitors inducing pemphigus. The observation of a patient in whom pemphigus vulgaris (PV) worsened after taking fosinopril prompted us to study an experimental way to assess its responsibility. Slices of normal human skin (NHS) were simultaneously incubated for 2, 6, 12 and 24 h at 4°C with progressively diluted fosinopril and captopril solutions and used as indirect immunofluorescence (IIF) substrates for 2 sera containing anti-desmoglein-3 (anti-Dsg3) antibodies at a dilution of 1/160. With captopril, IIF was negative, irrespective of dilution and time of incubation. Only at 1/40,000 dilution was IIF positive. With fosinopril, IIF was negative for the 2- and 6-hour-long incubations but turned positive after 12 h and so remained with all other solutions and incubation times. IIF negativity with captopril suggests that anti-Dsg3 antibodies contained in the PV sera were unable to find molecules in NHS to bind to. Captopril would therefore induce acantholysis by blocking the adhesion molecules. With fosinopril, instead, a partial block of the adhesion molecules was seen only with the very concentrated solution, unlikely to occur in vivo. Fosinopril, therefore, is probably unable to block the adhesion molecules in vivo. Our method might be used to verify the acantholytic properties of a drug.

Endothelin-1 Levels in Scleroderma Patients: A Pilot Study

Endothelin-1 (ET-1) is a potent endogenous vasoconstrictor, which mediates vascular wall cells proliferation, fibrosis, and inflammation through two types of ET-1 receptors (ET-A and ET-B). In our retrospective study the serum levels of ET-1 in 18 systemic sclerosis (SSc) patients with and without digital ulcers (DUs) were assessed to observe possible correlation between the levels of ET-1, the evolution of SSc, and the therapy with an ET-1 antagonist (bosentan). In all our patients, the levels of ET-1 were found higher than normal range and correlate with the severity of the disease. Furthermore we also observed that in patients without DUs the levels of ET-1 were higher and did not correlate with new DUs development. In conclusion, the levels of ET-1 in our studied patients do not correlate with the possible development of DUs. The reduction of ET-1 levels in DUs patients in therapy with bosentan confirms the efficacy of this molecule both for treatment and prevention of digital ulcers. The inhibition of ET-A receptor by its antagonist may activate the opposite ET-B receptors, with well-known function ET-1 degradation and reducing of ET-1 serum level as confirmed in our pilot study.

Are clinical phenotype and autoantibody profile always concordant in pemphigus? A study in a cohort of pemphigus patients.

BACKGROUND The clinical phenotype of different forms of pemphigus is reportedly defined by the anti-desmoglein (Dsg) autoantibody profile. In routine practice, however, this is not always the case. OBJECTIVES To verify the relationship between the anti-Dsg1 and -3 autoantibody profiles and titers on the one hand and the clinical phenotype and disease activity on the other. MATERIALS AND METHODS we followed-up clinically and serologically 20 pemphigus patients, including 3 mucosal pemphigus (mPV), 9 mucocutaneous pemphigus (mcPV), and 8 cutaneous pemphigus (PF). RESULTS We found that the cutaneous and/or mucosal involvement and the autoantibody profile were only concordant in mPV patients. On the contrary, in other clinical forms this correlation was often absent. CONCLUSIONS 1) The discrepancy between autoantibody profile and the clinical phenotype, at least in PF patients, appears to be due to non-pathogenic anti-Dsg3 antibodies; 2) in a proportion of patients the relationship between the Dsg1 and Dsg3 ELISA titers and the disease severity was absent; 3) in some patients, the anti-Dsg1 and -3 autoantibodies were lacking at diagnosis, suggesting a role of other antigens in the pathogenesis of the disease and, lastly, 4) the pure cutaneous and mucosal forms tend to respond more efficiently to the therapy than the mucocutaneous forms and have a persistent response.

Anti-citrulline antibodies in psoriatic patients with and without arthritis.

Sir, Psoriatic arthritis (PSA) is a manifestation of psoriasis present in up to 20% of patients with psoriasis. Five variants have been described: asymmetrical acute oligoarthritis, distal interphalangeal joint arthritis, rheumatoid arthritis-like symmetrical polyarthritis (which is the commonest form), spondylitis and arthritis mutilans. In the absence of typical cutaneous or nail lesions, PSA is easily confused with other forms of arthritis, especially rheumatoid arthritis (RA). Recently, antibodies directed to a citrullinated cyclic peptide (anti-CCP) have been proposed as a specific marker for RA (1, 2). We addressed the question as to whether anti-CCP antibodies may help to distinguish PSA from RA.

Scleroderma Subsets Are Best Detected by the Simultaneous Analysis of the Autoantibody Profile Using Commercial ELISA

Objective: Antinuclear antibodies are often present in patients with systemic sclerosis but do not provide useful prognostic information if studied individually. Although an autoantibody profile should be studied, this has never been done in a large series of patients. Methods: Anticentromere, anti-topoisomerase-I, anti-extractable-nuclear-antigen, antihistone and anticardiolipin antibodies were studied by means of enzyme immunosorbent assay in 90 systemic sclerosis patients. Results: We confirmed that anticentromere antibodies characterize limited forms of the disease with less frequent visceral involvement while anti-topoisomerase-I antibodies characterize diffuse forms with severe gastrointestinal, heart and lung involvement. Antihistone antibodies alone or associated with anticentromere antibodies characterize a disease subset with more frequent visceral involvement and a probably poor outcome. Patients with anticardiolipin antibodies, instead, did not display severer heart or vascular involvement. Conclusions: Systemic sclerosis patients are often found to have antinuclear antibodies. In addition to the well-known disease subsets identified by anti-topoisomerase-I and anticentromere antibodies, another one can be established, characterized by antihistone antibodies often associated with anticentromere antibodies. Patients displaying this profile have high prevalence of lung, kidney and heart involvement.