Increased excretion of urinary podocytes in lupus nephritis.

Podocytes are highly specialized epithelial cells that form part of the filtration barrier in the kidney, and their loss reflects a malfunction in glomerular filtration, which is usually associated with the progression of the disease. Glomerulonephritis is a serious complication that develops in about 50% of the lupus patients and is characterized by proteinuria arising from direct or indirect podocyte injury. To assess the possible role of podocytes in the pathogenesis of lupus nephritis (LN). Urinary and glomerular podocytes were detected in the kidney biopsies of patients (n = 17) with lupus nephritis, and from control biopsies obtained during autopsies. The WT-1 protein was used as a podocyte marker. The cumulative excretion of urinary podocytes was detected in the urinary sediments of LN patients and normal healthy controls, and the specimens were analyzed by immunohistochemistry, immunofluorescence, and enzyme-linked immunosorbent assay. The apoptotic index was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Gross proteinuria in lupus patients was determined via 24-hour urine samples, and the results were analyzed by Student t test. Biopsy specimens from 17 patients with class-III or IV LN had lower levels of glomerular WT-1 expression than the levels found in normal kidneys (P < 0.0001). The reduction of glomerular podocytes in patients with lupus nephritis correlated with the cumulative excretion of urinary podocytes (P < 0.0001) and proteinuria. There was no correlation between the urinary podocytes and the apoptotic index in the LN urinary sediments. A decrease in glomerular podocytes is associated with their cumulative excretion in urinary sediments; therefore, such findings correlate with proteinuria in lupus nephritis patients.

Caspase 3 blocking avoids the expression of autoantigens triggered by apoptosis in neonatal Balb/c mice skin.

OBJECTIVE: To assess the effect of caspase 3 inhibition, in the expression of intracellular antigens induced by apoptosis. MATERIAL AND METHODS: Skin explants of neonatal Balb/c mice were used to assess the autoantigen expression. Skin was obtained by punch biopsies, tissues were cultured in DMEM; cell death was induced by chemicals and assessed by TUNEL. The expression of La, Ro, Sm, RNP, Cajal Bodies and NuMa antigens were monitored by immunohistochemistry using autoantibodies or monoclonal antibodies against these antigens. RESULTS: Chemicals used to induce cell death, successfully produced apoptosis or necrosis in more than 60% of keratinocytes, and viability was significantly decreased when it was compared with those in controls. An increased expression of all skin intracellular antigens in skin biopsies treated with chemicals, major antigenic expression was detected with anti-La and anti-Ro antibodies. The caspase 3 inhibitor DEVD-CMK significantly decreased the expression of antigens induced by chemicals. CONCLUSION: By this result we can infer that caspase inhibitors modify apoptosis and decrease the autoantigens associated to cell death.

Infliximab treatment in a case of rheumatoid scleromalacia perforans.

Ocular rheumatoid disease manifests as hyperemia of the conjunctiva and episclera, and in severe cases, episcleritis can result in nodular sclerotic and scleromalacia perforans. A clinical case of scleromalacia perforans in a 56-year-old woman with 20 years of seropositive rheumatoid arthritis of functional class IV is presented here. During that period, she received exclusively non-steroidal anti-inflammatory drugs (NSAIDs). She developed acute episcleritis of the left ocular globe, which rapidly progressed to scleromalacia perforans. Since the left eye became perforated, it was surgically enucleated, and the patient was maintained with steroidal therapy. Nevertheless, two months later she developed new-onset episcleritis of the right eye followed by scleromalacia. She was first evaluated by a rheumatologist and treated with 200 mg/dose of infliximab, which was administered monthly for the following four months. The biological treatment was accompanied by methotrexate and prednisone. With this therapy, the ocular lesion dramatically improved, and complete remission of rheumatoid arthritis and scleritis was archived four months later. In conclusion, tumour necrosis factor (TNF) blockers are effective therapeutic agents in ocular complications of rheumatoid arthritis.

The final destiny of acantholytic cells in pemphigus is Fas mediated.

BACKGROUND: Pemphigus is an autoimmune disease characterized by the formation of intra-epidermal blisters. Patients develop auto-antibodies against desmoglein 1 and 3 proteins and induce acantholysis. OBJECTIVE: This work addresses the issue of whether the Fas pathway mediates acantholysis. Furthermore, the possible suppliers of the Fas pathway were investigated. METHODS: Seventeen biopsies of pemphigus patients were studied by haematoxylin and eosin staining, and apoptosis was defined by TUNEL. The expression of Fas, FasL and caspase 3 was studied by in situ hybridization and immunohistochemistry. Cell infiltrates were studied by immunofluorescence with monoclonal anti-CD3, CD4, CD8, CD19 and CD69. RESULTS: All of the biopsies showed intra-epidermal blisters, acantholytic cells and inflammatory infiltrates. The blisters expressed Fas, FasL and caspase 3. Cell infiltrates were composed of CD8 and a few CD4(+)CD69(+) cells. Additionally, CD19(+) cells were detected. Interestingly, the Fas expression was increased in acantholytic cells and perilesional keratinocytes. Incidentally, these cells exhibited apoptotic features. Interestingly, the CD8 cells expressed FasL. CONCLUSION: This paper presents the morphological evidence that apoptosis and acantholysis are linked. Therefore, the Fas pathway is associated with CD8 cells in pemphigus lesions.

Widespread expression of inducible NOS and citrulline in lupus nephritis tissues.

OBJECTIVE: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nephritis lesions. METHODS: Seventeen kidney biopsies from patients with lupus nephritis and an equal number of normal control kidney biopsies were examined for the presence of iNOS and endothelial nitric oxide synthase (eNOS) and citrulline by using immunohistochemical methods. Additionally, iNOS and eNOS mRNAs were examined by reverse transcription -PCR amplification of total renal RNA. RESULTS: All biopsies expressed constitutive eNOS, but in contrast to normal kidney biopsies, 70% of the lupus biopsies also expressed iNOS mRNA and the cognate protein. Eight positive biopsies corresponded to class IV lupus nephritis, which also had a high degree of citrullination. CONCLUSIONS: The data indicate that functional iNOS activity is present in glomeruli as part of the inflammatory process in the kidney; therefore the products of iNOS could play a role in the pathogenesis of lupus nephritis.

Intracellular antigens released from Balb/c mice kidneys under chemically induced apoptosis and/or necrosis.

The present investigation assesses the possible role of apoptosis and necrosis in intracellular antigen exposure of kidneys from Balb/c mice. Renal tissues were cultured and treated with chemicals to induce apoptosis and /or necrosis. The expression of intracellular antigens Sm, RNP, Ro and La were monitored with antibodies against these antigens. Main results confirm that renal intracellular antigens are released and exposed onto the surface of apoptotic and necrotic cells, therefore these antigens become an easy target of autoantibodies. This mechanism may be important in the lupus nephritis pathogenesis.

A dermatomyositis and scleroderma overlap syndrome with a remarkable high titer of anti-exosome antibodies.

An overlap syndrome of dermatomyositis and scleroderma is reported. The case corresponded to a 27-year-old female with a clinical picture of 14 months evolution, characterized by proximal muscles weakness, erythematous rash in wrists, knees, ankles, Gottron sign, heliotrope periorbital rash and dysphagia. A muscle biopsy was compatible with dermatomyositis; meanwhile the skin biopsy was compatible with scleroderma. Muscle enzymes were increased. Interestingly, the antinuclear antibody determination in HEp-2 cells was positive with a remarkable titer of 81,920 exhibiting a nucleolar pattern. Anti-Jo1 antibody was negative, but anti-PM/Scl-100 positive. The patient received methylprednisolone and cyclophosphamide pulses, with gradual improvement. Present report constitutes a case of overlap dermatomyositis-scleroderma syndrome, with anti-PM/Scl autoantibodies (anti-exosome). The remarkable of this case was the exceptional high antinucleolar antibody titer.

Ro60 and La ribonucleoproteins become self-aggregated by cell stress.

Ro and La antigens are of clinical interest in subacute cutaneous lupus erythematosus because skin lesions appear after UV irradiation, which induces the translocation of intracellular Ro and La ribonucleoproteins and trigger autoantibody production. Present studies address the question whether cellular stressors modify molecular characteristics and distribution of Ro60 and La proteins. To accomplish our goal HEp-2 cells were stressed by heat and UV irradiation and Ro and La expression was studied by indirect immunofluorescence and Western blot and crossed-immunoprecipitation using monoclonal anti-Ro/La or anti-HSP70 linked to CNBr-Sepharose 4B. Results of present studies confirm that Ro60 and La were located in the nuclei of non stressed cells; however under stress, both ribonucleoproteins were redistributed within cytoplasm and nucleoplasm, interestingly the stress induces self aggregation of both ribonucleoproteins, as demonstrated the Western blot assays. Ro and La proteins interact with the cytoskeleton protein via HSP70. In conclusion, the cell stress redistributes Ro and La proteins whiting nucleo-cytoplasmic compartments. This redistribution is accompanied by self aggregation of Ro and La which became associated with HSP70. Finally, the cell stress is an important factor for antigenic redistribution.

The role of apoptosis in autoantibody production.

Apoptosis is the physiologic process that guarantees the cellular exchange; after apoptosis the cellular remains are cleared by phagocytosis. In autoimmunity, some mechanisms in apoptosis fail and may result in disease. For instance, a failure in the Fas pathway during lymphoid ontogeny may allow the survival of autoimmune clones; equally the lack of clearance of apoptotic corps containing self-antigens may activate pre-existent auto-reactive clones and may result in autoantibody production. The role of apoptosis in autoimmunity is reviewed.

Scleroderma with type III glomerulonephritis and MPO-ANCA antibodies in the serum.

Scleroderma is an autoimmune disease characterized by early inflammatory infiltrates followed by fibrosis in the skin and internal organs. CREST is a relatively benign cutaneous variant of scleroderma that features calcinosis, Raynaud's phenomenon, oesophageal dysfunction, sclerodactyly and telangiectases. Glomerulonephritis is a rare association of CREST. We are reporting a patient with CREST who developed glomerulonephritis and had anticentromere and antineutrophil cytoplasmic autoantibodies (ANCA) in her serum.

Apoptosis and necrosis increase antigenicity of proteins recognized by antinuclear antibodies.

OBJECTIVE: Present study addresses the issue whether apoptosis and necrosis increases the antigenicity of proteins recognized by antinuclear antibodies. MATERIAL AND METHODS: HEp-2 cells were cultured in standard conditions; apoptosis was induced by camptothecin and necrosis by mercuric chloride. Protein antigenicity of cell extracts was tested onto nitrocellulose membranes and probed with positive or negative sera for antinuclear antibodies by a luminescent-dot-ELISA system. RESULTS: Apoptotic changes in HEp-2 cells appeared by 24 hours of camptothecin exposure, meanwhile the necrotic features become visible earlier. Luminescence was significantly superior in ANA positive sera than in ANA negative controls. Antinuclear antibody sera recognized better the antigens from the apoptotic and necrotic cells than controls without chemical treatments. CONCLUSIONS: Apoptosis and necrosis increase the ANA binding by better availability of intracellular antigens, or by disclosing cryptic epitopes.

Defective expression of FasL and Bax in human lung cancer.

The present studies investigated whether FasL and Bax genes are expressed in pleuro-pulmonary biopsies from patients with lung cancer. FasL, Bax, and TNFalpha mRNAs were detected in 19 biopsies of primary or metastasic lung cancer by fluorescent in situ hybridization assays. Fluorescent probes were produced by polymerase chain reaction using a human spleen lambda gt11 library and specific primers for FasL, Bax, and TNFalpha. Proteins were detected by immunohistochemistry using monoclonal anti- FasL, anti-Bax, and anti-TNFalpha antibodies. Chromatin fragmentation was detected by TUNEL. Seven negative samples from subjects without lung pathology were obtained during legal autopsies and 12 positive control biopsies from patients with lung infections were also included. Sixty-eight percent of lung cancer biopsies exhibited FasL; Bax was expressed in 68% and TNFalpha in 63%. FasL protein was detected in 21%, Bax protein in 26%, and TNFalpha was present in 31% of cancer biopsies. A low degree of apoptosis in lung cancer was demonstrated by TUNEL assays. A defect in FasL, Bax, and TNFalpha gene expression was found in lung cancer biopsies. Some tumors normally expressed the mRNA of FasL, Bax, or TNFalpha, but their proteins were absent, or were non-functional, since TUNEL assays were negative. Such a failure would contribute to cancer cell survival and dissemination.

Possible role of Hsp70 in autoantigen shuttling to the dermo-epidermal junction in systemic lupus erythematosus.

The lupus band is the result of immune complex deposition along the dermo-epidermal junction; such complexes are formed in situ by the interaction of antinuclear antibodies with their respective autoantigens. Dermal autoantigens are released after sun exposure, concurrently a heat shock protein production take place and would participate in autoantigen transfer to the dermo-epidermal junction. In this work the presence of Hsp70 along with the lupus band was investigated by immunofluorescence in twenty SLE skin biopsies. Immune deposits were mainly composed by IgM, IgG and C3 and were found in all lupus biopsies at the dermo-epidermal junction. Immunoreagents were also present into papillary vessels and, with less extent, into epidermal keratinocytes. Hsp70 was present in 60% of lupus biopsies, and was mainly distributed along dermo-epidermal junction and around papillary vessels. Furthermore, by double fluorescence labelling assays, we found that immuno-reactants are co-localized with Hsp70. Our results suggest that Hsp70 would shuttle autoantigens to the dermo-epidermal junction.

FasL and Bax genes are differentially expressed in acinar epithelium and inflammatory cells of primary Sjögren salivary glands.

AIM: Assess the expression of FasL, Bax, TNFa and IL-6, genes in salivary glands of primary Sjögren patients. METHODS: Twenty minor salivary glands from patients with primary Sjögren syndrome were studied by in situ hybridization with cDNA fluorescent probes. An equal number of control biopsies were included. RESULTS: Sjögren salivary glands differentially display the inflammatory cytokines and pro-apoptotic mRNAs as follows: mononuclear infiltrating cells exhibited IL-6 and TNFa, whereas the ductal epithelium and acinary cells mainly expressed FasL and Bax. Control biopsies were negative. CONCLUSION: Present data suggest that local production of inflammatory cytokines would induce the Fas and Bax pathways committing the ductal epithelium and the acinary cells to apoptosis.

TNFalpha and IL-6 are mediators in the blistering process of pemphigus.

BACKGROUND: Pemphigus is an autoimmune disease characterized by intraepidermal blisters induced by pemphigus IgG. In addition to autoantibodies, molecular mechanisms involved in acantholysis remain largely unknown. For this reason, we address a possible role of the inflammatory cytokines IL-6 and TNFalpha in pemphigus lesions. METHODS: Sixteen biopsies from patients with different types of pemphigus were studied by in situ hybridization using DNA fluorescent probes for IL-6 and TNFalpha mRNA. RESULTS: Fifty-six percent of lesional biopsies exhibited cytokine gene expression, which was poorly expressed in noninvolved skin. Deposits of TNFalpha and IL-6 were products of in situ transcription at the epidermal level. CONCLUSIONS: Inflammatory cytokine expression around the blister could play a mediator role in pemphigus lesions by increasing epithelial damage.

Anti-idiotype antibodies neutralize in vivo the blistering effect of Pemphigus foliaceus IgG.

Idiotypes are molecular clues used to explore the specificity and diversity of immune response. In the present study, anti-idiotype antibodies were used to neutralize the pathogenic effects induced by the injection of pemphigus immunoglobulin(Ig)G into BALB/c mice. To achieve our goal, antidesmoglein 1 IgG was obtained from a patient with pemphigus foliaceus with high titer of antiepithelial antibodies. The IgG was isolated by ion exchange chromatography, then digested by pepsin. F(ab')2 fragments were purified in Sephacryl S-300 and injected in rabbits to produce anti-idiotype antibodies. The rabbit sera reacted with the pemphigus F(ab')2 fragments. Eleven pemphigus foliaceus sera were recognized by the anti-idiotype serum at the light or heavy chains whereas bullous pemphigoid and normal IgG were negative. Neonatal BALB/c mice injected with pemphigus IgG developed intraepidermal blisters, mimicking the clinical and immunopathological features of the pemphigus. In contrast, the animals treated with anti-idiotype antibodies and pemphigus IgG did not develop blisters. Thus, anti-idiotype antibodies neutralize in vivo the pathogenic effects of pemphigus IgG.

Glomerular expression of Fas ligand and Bax mRNA in lupus nephritis.

The current studies were carried out to determine the expression of Fas ligand and Bax in kidneys from lupus nephritis as possible indicators of apoptosis. Twenty-four kidney biopsies from patients with lupus nephritis and 30 normal controls were studied for FasL and Bax gene expression by fluorescent in situ hybridization. Seventy percent of the lupus biopsies displayed FasL or Bax mRNAs. These genes were mainly expressed in biopsies with higher activity indices. In contrast, neither of these mediators was detected in normal glomeruli. These data suggest that FasL and Bax are up-regulated in lupus nephritis and may play a pathogenic role through apoptotic cascades.

Transplacental passage of maternal pemphigus foliaceus autoantibodies induces neonatal pemphigus.

The association of maternal pemphigus foliaceus (PF) with neonatal PF is rare and may be secondary to transplacental passage of PF autoantibodies. We describe a 25-year-old patient with PF who was delivered of two consecutive babies, one with classic skin lesions of PF and another that was normal. The neonate with PF was born when the mother had widespread skin disease; the normal newborn was born when the mother was in partial remission. The titers of PF autoantibodies were higher in the mother's serum and the cord serum of the baby with PF than in the mother during partial remission and the unaffected baby. The mother and affected baby had autoantibodies to desmoglein 1. Furthermore, cord blood from the baby with PF induced skin disease when injected into mice. In this case, maternal PF was associated with neonatal PF when the titers of maternal anti-desmoglein 1 autoantibodies were elevated. The cutaneous disease in neonatal PF is due to anti-desmoglein 1 autoantibodies.

Fas ligand and Bax gene transcription contributes to Ro60 ribonucleoprotein redistribution in UV-A irradiated human keratinocytes.

OBJECTIVES: Ro ribonucleoproteins are of particular interest because they are serologic markers of photosensitive variants of lupus such as the subacute cutaneous lupus erythematosus (SCLE), in which the polycyclic skin lesions are triggered by exposure to the sun. We study the role of apoptosis in the expression of Ro antigen. METHODS: We used UV-A irradiated keratinocytes. RESULTS: We demonstrate in cultured human UVA-irradiated keratinocytes that the enhanced expression of Ro60 ribonucleoprotein is caused by antigenic redistribution consecutive to Fas-L and Bax gene activation.

Anti-NuMA antibodies: an uncommon specificity in scleroderma sera.

BACKGROUND: Serum antibodies in scleroderma patients are generally directed against the nucleolus and centromeres. A small proportion of patients have serum antibodies to the centrioles and mitotic apparatus. OBJECTIVE: To determine the prevalence of serum autoantibodies against the mitotic apparatus in scleroderma patients. MATERIAL AND METHODS: Sera from 113 patients with various forms of scleroderma were tested for antinuclear antibodies by indirect immunofluorescence on HEp-2 cells. The specificity of the antibodies was determined by Western blot. RESULTS: Only two scleroderma sera recognized the mitotic apparatus. Western blot results showed that in both cases the target was an about 235 kDa protein corresponding to the NuMA determinant. Affinity-purified anti-NuMa antibodies were used to perform immunolocalization in synchronized HEp-2 cells using scanning laser confocal microscopy. The anti-NuMA autoantibodies recognized the mitotic asters but neither the centrioles nor the microtubules. CONCLUSION: Our data suggest that anti-NuMA autoantibodies may be devoid of clinical significance in scleroderma. However, they remain useful as probes in cell biology studies.