New insights into immune mechanisms underlying response to Rituximab in patients with membranous nephropathy: A prospective study and a review of the literature.

BACKGROUND: Idiopathic membranous nephropathy (MN) is a common immune-mediated glomerular disease and the main cause of nephrotic syndrome (NS) in Caucasian adults. Rituximab (RTX) has been reported to safely reduce proteinuria in patients with primary MN and severe NS. However, the effects of RTX treatment on T-cells including regulatory T-cells (Treg) in MN have not been fully determined. METHODS: Seventeen patients [mean age 67 (29-86) years, 6 women, 11 men] with biopsy-proven MN, and persistent proteinuria >3.5 g/24h were prospectively enrolled and received RTX, 375 mg/m(2) (iv) on days 1, 8, 15 and 22. Changes in circulating B and T cell homeostasis were examined in the peripheral blood by flow-cytometry studies; serum levels of IL-35 were measured using a high-sensitivity ELISA kits (baseline, at month 3, 6, 9 and 12). RESULTS: Patients had been followed-up for a mean of 36.3 months (24-48). Proteinuria decreased from 5.6 (3.5-8) g/24h to 2.4 (0.06-13) g/24h at 6 months (p<0.05) and to 1.3 (0.06-8) at 12 months (p<0.01), respectively after therapy with RTX. Four patients received a 2nd course of RTX (one at 6 months because of persistent NS, and three at 12, 18, or 30 months for relapse). The three relapsing patients became proteinuria-free (<0.5 g/24h) in the following 6 months. Serum creatinine remained stable during the follow-up: median 1mg/dl (0.7-1.6) at 12 months and 1.1 (0.7-1.7) at 24 months as compared to 1 (0.5-2.4) at baseline. At 6 months after RTX, complete remission (CR) was observed in 7 patients, partial remission (PR) in 4, while 6 were non responders (NR) non responder (NR). At the end of the follow-up, 14 patients were in CR, 1 in PR, while 2 were NR. In the T-cell compartment, upon detection of B cell depletion, there was an increase in Treg up to 10-fold when comparing baseline and at month 12 (mean ± SD 1.2 ± 0.6%, and 5.8 ± 0.7% p=0.02, respectively). When stratifying patients in responders (CR+PR) and NRs at month 12, we observed a significant increase in Treg cells from month 6 which persisted till 12 months only in the responder group (5.5 ± 0.6% and 1.1 ± 0.6%, p=0.04, respectively in responders and NRs). A statistically significant decrease in the levels of active T-lymphocytes (HLA-DR+CD8+ cells) was observed, with a maximum reached at 12 months after treatment with RTX [6 ± 1.1% baseline, 4.7 ± 1.7% at 6 months (p=0.043) and 1.5 ± 1.4% at 12 months (p=0.05)]. A marked increase in IL-35 levels [defined as delta >40% (serum values at 6 months minus baseline values)] was seen in 68% of the patients who achieved clinical response (CR or PR) at 12 month, but in none of the patients who failed to respond (p=0.034). CONCLUSION: Our findings and data from literature support the idea that RTX can be envisaged as a first-line therapy for patients at risk of progression because of persistent NS due to idiopathic MN. Insights into the putative T cell-related mechanisms of action have been discussed.

Kidney biopsy in pregnancy: evidence for counselling? A systematic narrative review.

BACKGROUND: Kidney diseases, which have a prevalence of 3% in women of childbearing age, are increasingly encountered in pregnancy. Glomerulonephritis may develop or flare up in pregnancy, and a differential diagnosis with pre-eclampsia may be impossible on clinical grounds. Use of kidney biopsy is controversial, but a systematic review has not been carried out to date. OBJECTIVES: To review the literature on kidney biopsy in pregnancy, with a focus on indications, risks and timing. SEARCH STRATEGY: Medline, Embase, CHINAL and the Cochrane Library were searched in September 2012, with 'pregnancy' and 'kidney biopsy' used as MESH and free terms, for the period 1980-2012. Results were filtered for 'human' if this option was available. SELECTION CRITERIA: Biopsies during pregnancy and within 2 months after delivery. Case reports (fewer than five cases) and kidney grafts were excluded. Paper selection was performed in duplicate. DATA COLLECTION AND ANALYSIS: Data were extracted in duplicate. The high heterogeneity in study design necessitated that the review be narrative, except for data on adverse events, which were analysed with regard to the timing of kidney biopsy. MAIN RESULTS: Of 949 references, 39 were selected, providing data on 243 biopsies in pregnancy and 1236 after delivery (timing was unclear in 106 women). The main aims of the studies were to define morphology in pre-eclampsia (23 studies), to carry out a risk-benefit analysis of kidney biopsy (11 studies), and to investigate pregnancy-related acute kidney injury (five studies). Four cases of major bleeding complications occurred at 23-26 weeks of gestation. Relevant complications were observed in 7% of women during pregnancy and 1% after delivery (P = 0.001). Kidney biopsy performed for the diagnosis of glomerulonephritis or pre-eclampsia led to therapeutic changes in 66% of cases. AUTHORS' CONCLUSIONS: The evidence on kidney biopsy in pregnancy is heterogeneous, but a significantly higher risk of complications (relative to postpartum biopsy) was found, with a possible peak at around 25 gestational weeks.

NEMO syndrome (incontinentia pigmenti) and systemic lupus erythematosus: a new disease association.

Congenital diseases are increasingly being recognised in adults because of clinical mimicry, variable clinical picture or rarity of the disease; pregnancy is a valuable diagnostic occasion. The present case is the first report of an association report between NEMO syndrome (an acronym of the mutated, non-functioning gene, NF-kB essential modulator), a rare X-linked disease, characterised by developmental anomalies, immunodepression and skin lesions, and systemic lupus erythematosus (SLE). A 35-year-old patient affected by SLE sought clinical advice in the 8th week of gestation. The diagnosis of SLE dated back to the age of 24, when multisystemic manifestations (pleuropericarditis, weight loss, alopecia, skin involvement, joint pain, kidney involvement) were observed. She had been treated with steroids since 1999; immunosuppressive drugs had been added for short periods. Developmental anomalies were present, including oligodontia, retinal problems, anomalies of the corpus callosum and pes planovalgus. Family history included multiple miscarriages, dental malformations and oligodontia and skin blistering in the first months of life. On these bases, incontinentia pigmenti (IP; or NEMO syndrome) was diagnosed and confirmed by genetic testing. The NEMO gene is implicated in immune deficiencies as well as in autoimmune diseases. This report may suggest a role for NF-kB essential modulator in the pathogenesis of SLE, in the context of the complex immunologic deficiencies increasingly associated with autoimmune diseases.

Effects of anti-CD20 monoclonal antibody as a rescue treatment for ANCA-associated idiopathic systemic vasculitis with or without overt renal involvement.

BACKGROUND: Cyclophosphamide (CYC) is thought to be the most effective treatment for antineutrophil cytoplasmatic antibody (ANCA)-associated idiopathic systemic vasculitis with severe organ or life threatening presentation. The key mechanism of action of CYC is suppression of the B lymphocyte activity. However, a considerable minority of patients either remains refractory to conventional therapy or experiences dose-limiting side effects. METHODS: In the present study, rituximab (4 weekly doses of 375 mg/m2 and 2 more doses at 1-month interval) was intravenously administered as a rescue therapy to 7 patients (4 affected by idiopathic systemic microscopic polyangiitis, 2 by Wegener's granulomatosis, and 1 affected by Churg Strauss syndrome). The study group was made up of 3 women and 4 men, mean age 61.5 years (39-71), intolerant or refractory to more conventional therapy. Four patients had histologically confirmed paucimmune necrotizing glomerulonephritis. RESULTS: Significant decreases were observed in levels of serum creatinine, proteinuria, erythrocyte sedimentation rate, C-reactive protein, and ANCA titers within the first 12 months of follow-up. Arthralgia and weakness rapidly disappeared in all patients. Four out of five patients reported a decrease in the degree of paresthesia, paralleled by an improvement in the electrodiagnostic parameters. A significant improvement was observed in both Birmingham Vasculitis Activity Score and Vasculitis Damage Index. Side effects were negligible. CONCLUSION: In this sample of patients with idiopathic systemic vasculitis that was refractory or intolerant to conventional treatment, rituximab was found to be a safe and effective rescue therapy.

Anti-neuronal antibodies in patients with HCV-related mixed cryoglobulinemia.

Mixed cryoglobulinemia (MC) is an immunological disorder characterized by immune-complex-mediated systemic vasculitis involving small vessels, which may present with renal, cutaneous, rheumatologic, and/or neurological manifestations. Until recently, the possible appearance of anti-neuronal autoantibodies in peripheral neuropathy occurring in the context of hepatitis C virus (HCV)-associated IgMk/IgG MC has not been extensively addressed. Therefore, a sample of these patients were evaluated by means of immuno-enzyme methods of anti-neuronal autoantibody detection. A significant increase in plasma titers of both anti-GM1 ganglioside and anti-sulfatide was observed. Abnormal titers were associated with evidence of active neuropathy as assessed by electrophysiologic studies. While peripheral neuropathy was traditionally thought to result from axonal ischemic damage caused by deposits of cryoprecipitable immune complexes in the vasa nervorum, a significant association between anti-GM1 and anti-sulfatide antibodies and involvement of the peripheral nervous system was observed in HCV-associated mixed IgMk/IgG cryoglobulinemia. Anti-neuronal reactivity could be a direct trigger of neurologic injury in this disorder.

Anti-GM1 and anti-sulfatide antibodies in patients with systemic lupus erythematosus, Sjögren's syndrome, mixed cryoglobulinemia and idiopathic systemic vasculitis.

OBJECTIVES: Over the last two decades, increasing interest has been focused on the association between autoimmune polyneuropathies and anti-neuronal autoantibodies in immune-mediated polyneuropathy. The possible appearance of these autoantibodies in systemic diseases that are not limited to the nervous system has not been fully addressed yet. METHODS: We evaluated 32 patients with systemic lupus erythematosus, 34 patients with hepatitis C virus-associated mixed IgM-k/IgG cryoglobulinemia, 19 with small vessel ANCA-associated vasculitis, and 20 patients with Sjögren's syndrome by means of an immunoenzyme method of anti-neuronal autoantibody detection. RESULTS: As compared to normals, a significant increase (p < 0.001) in plasma titers of both IgM and IgG anti-GM1 ganglioside and IgM and IgG anti-sulfatide was observed in patients with systemic lupus erythematosus, mixed cryoglobulinemia and Sjög-ren's syndrome. Idiopathic systemic vasculitis patients were found to have significantly increased levels of anti-sulfatide IgG autoantibodies (p < 0.001). Clinical and electrophysiologic studies revealed that abnormal titers of anti-neuronal antibodies were associated with evidence of neuropathy in patients with systemic lupus erythematosus and ANCA-related vasculitis (p < 0.05) as well as in patients with mixed cryoglobulinemia and Sjögren's syndrome (p < 0.001). CONCLUSION: Anti-GM1 and anti-sulfatide antibodies are frequently found in patients with small vessel ANCA-associated vasculitis and other multi-organ immune-mediated diseases. Upon detection of these antibodies, accurate neurologic examination should be carried out due to the significant association that can be found between these serologic abnormalities and the involvement of the peripheral nervous system as also detected by electrophysiologic studies. This study supports the unexpected possibility that anti-neuronal reactivity may be a direct trigger of neurologic injury in these systemic disorders.

[Anti-GM1 and anti-sulphatide antibodies in systemic idiopathic vasculitis, systemic lupus erythematosus and mixed cryoglobulinaemia: Serum detection and clinical and electrophysiologic correlations]. / Gli anticorpi anti-GM1 ed anti-solfatidi nelle Vasculiti sistemiche primitive, nel Lupus eritematoso sistemico e nella Crioglobulinemia mista: dosaggio sierico e correlazioni clinico-elettromiografiche.

BACKGROUND: In the last two decades increasing interest has been focused on the association between autoimmune polyneuropathies and high titers of anti-nervous serum autoantibodies. High titer of IgG anti-GM1 antibody could be detected in Guillain Barre' syndrome and in chronic painful axonal sensory immune-mediated polyneuropathy. The possible occurrence of anti-nervous autoantibodies in autoimmune diseases not limited to the nervous system is still under study. METHODS: We evaluated 29 patients with systemic lupus erythematosus (SLE), 19 with biopsy-proven renal involvement, 28 patients with mixed IgM-K/IgG polyclonal cryoglobulinaemia (18 with glomerulonephritis) and 19 with small-sized vessel ANCA-associated vasculitis (12 with renal involvement) by using a sensitive immunoenzyme method of autoantibody detection. RESULTS: Compared to controls (1/176+/-1/205; 1:204+/-1:103), we found a significant increase in plasma IgM and IgG anti-GM1 titers (1:643+/-1:531; 1:444+/-1:309) in SLE patients (p<0.0001). We also found IgM (1:3032+/-1:2844) and IgG (1:1560) anti-sulphatide titers to be higher than the control group (p<0.0001). Mean plasma IgM and IgG anti-GM1 titers of the cryoglobulinaemic patients were 1:524+/-1:403 and 1:501+/-1:415, respectively, once again higher than the controls (p<0.0001). Mean plasma IgM and IgG anti-sulphatide titers in this group were 1:1864+/-1:1189 and 1:1350 (p<0.0001). We found idiopathic systemic vasculitis patients to have significantly increased levels of anti-sulphatides IgG class autoantibodies (1:1400; p<0.0001). We found no correlation with the serologic markers for vasculitis or the clinical or histologic extent of renal involvement. Electrophysiologic studies revealed that in 38% of SLE patients (p<0.005), 61% of cryoglobulinaemic patients (p<0.01) and 42% of ANCA-related vasculitic patients (p<0.01) the abnormal titers of antineuronal antibodies were associated with clinical or subclinical evidence of neuropathy. CONCLUSIONS: In patients with systemic idiopathic or secondary vasculitis anti-GM1 and anti-sulphatide antibodies can frequently be found. Their presence should prompt an accurate neurological examination because these serologic abnormalities are significantly associated with neurologic, often subclinical, involvement. Antineuronal reactivity might be the epiphenomenon of primary phylogistic damage, which exposes normally segregated neuronal epitopes or be directly involved in triggering neurological injury.