Cryoglobulinemic vasculitis

Recurrent localized fever caused by cryoglobulinemic vasculitis following hemodialysis: A case report

Post-dialysis fever is commonly reported in patients undergoing hemodialysis (HD). However, it is often challenging to identify the underlying cause owing to the wide variety of potential factors that can lead to fever. In this case, a 66-year-old Japanese man experienced recurrent fever after HD treatment. Initially, antibiotics were prescribed to treat pneumonia, but it was later discovered that the pneumonia was an alveolar hemorrhage caused by cryoglobulinemic vasculitis. It is believed that cryoglobulin was sensitized by cold exposure owing to the dialysate temperature, which resulted in fever being experienced only after HD. Although treatment for vasculitis required prednisolone and rituximab, simple plasma exchange and a dialysate temperature of 37.5 °C dramatically suppressed the occurrence of post-dialysis fever. Cryoglobulinemia should be considered as a potential cause of fever, as it may be a common occurrence in patients undergoing HD and could be overlooked as a possible cause of localized fever following HD treatment.

Vasculitis: When to Consider this Diagnosis?

Vasculitis is a diverse group of disorders involving inflammation of the blood vessels. Approaching the diagnosis of vasculitis can be challenging, given the differing clinical presentation and organ manifestations. Often vasculitis is a diagnosis that is considered too late, given the heterogeneous presentation and various mimics. This article aims to provide physicians with a diagnostic approach to vasculitis.

A Rare Case of Nephrotic Syndrome in the Setting of Sjogren Syndrome-related Cryoglobulinemic Vasculitis

Cryoglobulinemia is a rare entity which frequently occurs in the setting of an underlying disease, with chronic hepatitis C virus infections and primary Sjogren syndrome being the most common underlying conditions. Cryoglobulinemic vasculitis (CV) is an immune-mediated type of small-vessel vasculitis with a broad spectrum of specific organ involvement, including renal, pulmonary, peripheral nerve, and cutaneous involvement and variable manifestations that can be life threatening. Moreover, a strong relationship between cryoglobulinemia and CV, with the future development of lymphoma, is well established. We present the case of a 72-year-old Caucasian male referred for nephrotic syndrome and acute renal injury. A diagnosis of Sjogren syndrome-associated CV was made, and he was successfully treated with rituximab and plasma exchange sessions.

Persistence of Cryoglobulinemic Vasculitis after DAA Induced HCV Cure

Treatment with a direct acting antiviral (DAA) has revolutionized HCV therapy, as more than 95% of patients achieve a sustained virological response (SVR). Cryoglobulinemic vasculitis (CryoVas), however, can persist and recur after the HCV cure. In this systematic review, we include data from 19 studies that provided information on the persistence and recurrence of CryoVas after the HCV cure with DAAs. A complete clinical response (CR) was reported in 63.7% to 90.2% of the DAA-treated patients after achieving SVR. Relapse of CryoVas symptoms was reported in 4% to 18% of the patients. Neuropathy, nephropathy, and dermatological complications were the most common manifestations of CryoVas. B-cell clones persisted in 31-40% of the patients and could contribute to CryoVas relapse. INFL3-rs12979860, ARNTL-rs648122, RETN-rs1423096, and SERPINE1-rs6976053 were associated with a higher incidence of persistence and recurrence of CryoVas. Prospective multicenter studies with diverse patient populations are needed to validate these findings for the timely and effective management of this challenging condition.

Cryoglobulins: Identification, classification, and novel biomarkers of mysterious proteins

Cryoglobulins consist of serum immunoglobulins that precipitate below 37°C and resolubilize upon warming. The clinical triad of cryoglobulinemia usually includes purpura, weakness, and arthralgia. Cryoglobulinemic syndrome, clinically defined as a systemic vasculitis, is associated with chronic infection with hepatitis C virus (HCV) and autoimmune disorders and can evolve into B-cell malignancies. While the current literature about HCV-associated cryoglobulinemia is not very limited, little is known about the immunologic and serologic profiles of affected patients. Therefore, comprehension of the pathogenetic mechanisms underlying cryoprecipitation could be very helpful. Due to the persistence of viral antigenic stimulation, biomarkers to use after the worsening progression of HCV infection to lymphoproliferative and/or autoimmune diseases are widely needed. Laboratory methods used to detect and characterize low concentrations of cryoprecipitates and immunotyping patterns could improve patient management. The most critical factor affecting cryoglobulin testing is that the pre-analytical phase is not fully completed at 37°C.

New insights in cryoglobulinemic vasculitis

Cryoglobulins are antibodies that precipitate at low temperatures and dissolve after rewarming. Cryoglobulinemia refers to the presence of circulating cryoglobulins and generally leads to a systemic inflammatory syndrome characterized by fatigue, arthralgia, purpura, ulcers, neuropathy and/or glomerulonephritis. The disease mainly involves small to medium-sized blood vessels and causes vasculitis due to cryoglobulin-containing immune complexes. Cryoglobulinemia is classified into three types (I, II and III) on the basis of immunoglobulin composition. Predisposing conditions include lymphoproliferative, autoimmune diseases and hepatitis C virus infection. The diagnosis of cryoglobulinemic syndrome is predominantly based on the presence of clinical features and laboratorial demonstration of serum cryoglobulins. The treatment strategy depends on the cause of cryoglobulinemia. For patients with chronic HCV infection, antiviral therapy is indicated. Immunosuppressive or immunomodulatory therapy, including steroids, plasmapheresis and cytotoxic agents, is reserved for organ-threatening manifestations. In this review, we discuss the main clinical presentations, diagnostic approach and treatment options.

Clinical practice: hepatitis C virus infection, cryoglobulinemia and cryoglobulinemic vasculitis

Cryoglobulins are circulating immunoglobulins that reversibly precipitate at temperatures below 37 °C. Type-II cryoglobulins consist of monoclonal IgM/polyclonal IgG immune complexes (ICs), whereas in type-III cryoglobulins both IgM and IgG are polyclonal. The clinical condition resulting from the presence of cryoglobulins in the blood is called mixed cryoglobulinemia (MC), which can be asymptomatic or manifest as cryoglobulinemic vasculitis (CV). Type-I cryoglobulins, consisting of a single monoclonal isotype, are detected in patients with lymphoproliferative disorders. It is now established that > 90% of MCs are associated with HCV infection. Clinically, the spectrum of symptoms may range in severity from occasional purpuric eruptions to life-threatening features. In addition to the development of liver cirrhosis and hepatocellular carcinoma, the possible progression of HCV-positive CV patients to B-cell non-Hodgkin lymphoma (B-NHL) has been reported. The pathogenetic role played by HCV infection in the onset of B-NHL is suggested by regression of the latter following the achievement of a sustained virologic response (SVR). For several years, interferon-α alone or combined with ribavirin has been the standard of care. However, the rates of clinical, biochemical, and virologic responses have been low, and the occurrence of relapse frequent. The addition of rituximab has resulted in a higher rate of responses. With the advent of direct-acting antiviral agents, SVR has been achieved in ~ 95% of CV patients. However, in a minority of patients, despite SVR, CV may persist or reappear over variable lengths of time from the completion of therapy. The eventual appearance of B-NHL is also possible.

Advances in HCV and Cryoglobulinemic Vasculitis in the Era of DAAs: Are We at the End of the Road?

Hepatitis C Virus (HCV)-related Mixed Cryoglobulinemia (MC) is a unique condition with complex pathogenesis that involves HCV antigen-driven B-lymphocyte clonal proliferation and mutagenesis. Clinical spectrum of MC ranges from asymptomatic state to clinically-apparent vasculitis involving multiple organs. In the era of Direct-Acting Antiviral (DAA) therapy, patients with HCV-related MC achieve high rates of viral clearance that is commonly accompanied by an improvement in clinical symptoms as well as immunological profiles. Rituximab, either alone or in combination with DAA, has also been shown to be effective. Nevertheless, there have been limited and somewhat conflicting data, particularly over the long-term, regarding the rate and degree of clinical response of MC following DAA therapy. It appears that we have come quite a long way in the last decade with this condition. As with non-MC related HCV, undoubtedly long term outcome data will be forthcoming over the next few years. As we move forward successful therapy of HCV is not likely to be a challenge in contrast to access to therapy.

Role of ribavirin in the treatment of hepatitis C virus-associated mixed cryoglobulinemia with interferon-free regimens

Mixed cryoglobulinemia (MC) is the most common extrahepatic manifestation of chronic hepatitis C (CHC), with the presence of symptoms in 10-15% of cases. There have been encouraging data regarding immunological and clinical responses in patients treated with the novel combinations of direct-acting antivirals (DAAs), but the role of ribavirin (RBV) in the treatment of MC has not yet been demonstrated. We prospectively enrolled 132 patients affected by MC and CHC, and virological, immunological and clinical responses were evaluated at 12 weeks after completion of treatment. All subjects were treated with interferon (IFN)-free regimens according to clinical guidelines, with or without RBV. All patients achieved a virological response. A complete immunological response (CR) was observed in 71 subjects (53.8%), a partial response in 44 (33.3%), and no response in 17 (12.8%). Ten patients showed a complete resolution of symptoms (7.6%), and 31 showed a significant improvement (23.5%). CR was significantly higher in patients taking RBV (71.1 vs. 44.8%, p < 0.001) and in treatment-naïve patients (62.5 vs. 43.3%, p < 0.001). In logistic regression analysis, duration of HCV infection of less than 20 years (OR 2.448; 95% IC 1.335-6.202; p = 0.019), treatment-naïve status (OR 2.885; 95% IC 1.404-9.660; p = 0.025) and the use of RBV (OR 6.961; 95% IC 3.912-26.885; p < 0.001) were predictors of CR. In MC patients, IFN-free regimens are effective and well tolerated, and RBV seems to significantly increase the immunological response and promote a decline in cryocrit.

Recovery of hepatitis C specific T-cell responses after rituximab therapy in hepatitis C mixed cryoglobulinemic vasculitis

Mixed cryoglobulinemic vasculitis is associated with monoclonal B cell expansion in patients with chronic hepatitis C (HCV) infection. B cell depletion therapy using rituximab, a CD20 monoclonal antibody, has been successful in achieving remission from symptomatic disease. This study investigated whether B cell depletion therapy has an impact on activation of HCV-specific T cell phenotype and function. Nineteen patients with Hepatitis C mixed cryoglobulinemic vasculitis were treated with 4 cycles of rituximab (375 mg/m² ) and variables were measured 6 months after therapy. Using flow cytometry and Enzyme-Linked Immunospot assay, the number of activated and tissue-like B cells and number of T cells expressing Programmed cell death protein 1 (PD-1), T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), and multiple cytokines were measured before and after rituximab therapy. B cell depletion therapy is associated with a significant (P < 0.0001) decline in peripheral T cells with exhaustive phenotype, from pre-therapy to post-therapy-of rituximab (mean ± standard error): CD4+ (16.9 ± 0.9% to 8.9 ± 1.0%) and CD8+ (6.8 ± 0.6% to 3.0 ± 0.5%) T cells expressing PD-1 and CD4+ (11.0 ± 1.0% to 6.1 ± 0.8%) and CD8+ (12.7 ± 0.7% to 6.4 ± 0.4%) T cells expressing TIM-3. In addition, there was a significantly higher percentage of peripheral CD8+ T cells responding to HCV peptide stimulation in vitro secreting IFN-γ (4.55 ± 0.3 to 9.6 ± 1.0 IFN-γ/10⁶ PBMCs, P < 0.0001), and more than one cytokine (1.3 ± 0.1% to 3.8 ± 0.2%, P < 0.0001) after therapy compared to pre-therapy. B cell depletion therapy results in recovery of T cell exhaustion and function in patients with HCV cryoglobulinemic vasculitis.

Transcriptional profiling of PBMCs unravels B cell mediated immunopathogenic imprints of HCV vasculitis

B cell depletion therapy using rituximab has been shown to be effective in achieving remission in patients with HCV-mixed cryoglobulinemic (MC) vasculitis. Previously, we have demonstrated abnormalities in peripheral immune cells involving neutrophils, chemotaxis, and innate immune activation among patients with HCV-MC vasculitis when compared to HCV patients without vasculitis. In this study, we evaluated the effect of B cell depletion therapy on transcriptional profiles of peripheral blood mononuclear cells before and after riruximab therapy, in order to unravel the pathogenic mechanism involved in HCV-MC vasculitis induced by abnormal B cell proliferation. DNA microarray analysis was performed using RNA from PBMCs from seven patients with HCV-MC vasculitis and seven normal volunteers. DNA was hybridized to Affymetrix U133A chips. After normalization, differentially expressed gene list with treatment was generated using partitional clustering. RT-PCR, flow cytometry, and enzyme immunoassay (EIA) was used to validate DNA microarray findings. Differentially expressed genes included B cells and non-B cell genes. Validation of genes using purified cell subsets demonstrated distinct effect of B cell depletion therapy on non-B cells, such as monocytes, T cells, and NK cells. Notably, B lymphocyte stimulator (BLyS) levels were persistently elevated in patients who subsequently relapsed. In conclusion, pathogenesis of HCV-MC vasculitis is mediated by abnormal proliferation of B cells, driven by BLyS, leading to significant effects on non-B cells in mediating symptomatology. Future therapeutics using a combination approach of B cell depletion and proliferation may be desired to achieve long-term remission.

Managing refractory cryoglobulinemic vasculitis: challenges and solutions

Cryoglobulinemia is thought to be a rare condition. It may be an isolated disorder or secondary to a particular disease. According to immunoglobulin composition, cryoglobulinemia is classified into three types. In mixed cryoglobulinemia (types II and III), vascular deposition of cryoglobulin-containing immune complexes and complement may induce a clinical syndrome, characterized by systemic vasculitis and inflammation – cryoglobulinemic vasculitis (CryoVas). Most common clinical manifestations in CryoVas are skin lesions (orthostatic purpura and ulcers), weakness, peripheral neuropathy, Raynaud’s phenomenon, sicca syndrome, membranoproliferative glomerulonephritis, and arthralgia and seldom arthritis. In patients with mixed cryoglobulinemia, prevalence of anti-hepatitis C virus (HCV) antibodies and/or HCV RNA, detected by polymerase chain reaction (PCR), is reported to be up to 90%, indicating a significant role of HCV in the development of this condition. The goals of therapy for mixed cryoglobulinemia include immunoglobulin level reduction and antigen elimination. CryoVas not associated with HCV infection should be treated according to treatment recommendations for small-vessel vasculitides. CryoVas associated with chronic HCV infection should be treated with antivirals along with immunosuppressive drugs, with or without plasmapheresis, depending on disease severity and organ involvement. Patients who do not respond to first-line therapy may achieve remission when treatment with rituximab is started as second-line therapy. In HCV-related CryoVas, antiviral therapy should be given along with rituximab in order to achieve complete or partial remission. Moreover, rituximab has proven to be a glucocorticoid-sparing medication. Other potential therapies for refractory CryoVas include mycophenolate mofetil and belimumab, while tumor necrosis factor (TNF) inhibitors are not effective.

Decline of cellular activation in non-B cells after rituximab treatment in hepatitis C-associated mixed cryoglobulinemia vasculitis

Mixed cryoglobulinemic vasculitis is associated with the monoclonal expansion of pathognomonic B cells in chronic hepatitis C. Recently, treatment with B-cell depletion, including rituximab, a CD20 monoclonal antibody, has been successful in achieving remission from the active disease. We investigated whether B-cell depletion therapy has an impact on activation of non-B cells in the periphery. Results demonstrated that B-cell depletion therapy is associated with a statistically significant decline in activated T cells, from pretherapy to follow-up while on rituximab therapy: CD4+ CD38+ HLA-DR+ (DR+), CD8+ CD38, CD8+ CD38+ DR+, and CD8+ DR+. Birmingham Vasculitis Activity Score and cryoglobulin had a strong correlation coefficient (R) of 0.72 (P=.0005), while cryoglobulin showed moderate correlation with CD8+ DR+ (R=.61), CD3+ CD38+ DR+ (R=.57), CD3+ DR+ (R=.50), CD4+ CD38+ DR+ (R=.53), CD4+ DR+ (R=.52), and CD8+ CD38+ DR+ (R=.67). These results suggest B-cell expansion has a direct and indirect effect on the pathogenesis of Hepatitis C-associated mixed cryoglobulinemic vasculitis.

Immune Monitoring of Trans-endothelial Transport by Kidney-Resident Macrophages

Small immune complexes cause type III hypersensitivity reactions that frequently result in tissue injury. The responsible mechanisms, however, remain unclear and differ depending on target organs. Here, we identify a kidney-specific anatomical and functional unit, formed by resident macrophages and peritubular capillary endothelial cells, which monitors the transport of proteins and particles ranging from 20 to 700 kDa or 10 to 200 nm into the kidney interstitium. Kidney-resident macrophages detect and scavenge circulating immune complexes "pumped" into the interstitium via trans-endothelial transport and trigger a FcγRIV-dependent inflammatory response and the recruitment of monocytes and neutrophils. In addition, FcγRIV and TLR pathways synergistically "super-activate" kidney macrophages when immune complexes contain a nucleic acid. These data identify a physiological function of tissue-resident kidney macrophages and a basic mechanism by which they initiate the inflammatory response to small immune complexes in the kidney.

The correlation between antiphospholipid syndrome and cryoglobulinemia: case series of 4 patients and review of the literature

BACKGROUND

Cryoglobulinemia is an immune-complex-mediated small vessel vasculitis that classically involves the skin, kidneys and peripheral nerves. Antiphospholipid syndrome (APS) is an autoimmune hypercoagulable disorder which causes blood vessel thrombosis. It can present as a multi-organ microthrombotic disorder which is called catastrophic APS.

OBJECTIVE

In this case series we aim to describe the diagnostic and management challenges that arise when these two severe disorders simultaneously present in the same patient.

METHODS

We describe four patients who were admitted to our hospital due to multi-organ life threatening damage mediated by cryoglobulinemic vasculitis with concurrent APS.

RESULTS

Clinical manifestations included leg ulcers, livedo reticularis, renal failure, and peripheral neuropathy. Suggested etiologies for the combined syndromes were hepatitis C, systemic lupus erythematosus and myeloproliferative disease rectal maltoma. All of our patients were treated with anticoagulation, high-dose corticosteroids, rituximab, intravenous gammaglobulins and plasma exchange.

CONCLUSION

The rare association of severe or catastrophic APS with cryoglobulinemia in patients should be considered by physicians who treat patients with multi-organ ischemia or necrosis.

Diagnostic approach in patients with suspected vasculitis

Vasculitides are a heterogeneous group of disorders that share the common feature of inflammation of the blood vessel wall. Vasculitis can be a systemic or localized process and depending on the disorder can affect large, medium, or small vessels. Vascular physicians including interventional radiologists often may be involved early in these cases before the establishment of a diagnosis as these patients may present with manifestations attributable to occlusive vascular syndromes. In this article, we discuss the presenting signs and symptoms of patients with vasculitis as well as laboratory and imaging studies required to further evaluate these disorders and treatment options, which include interventional as well as noninterventional options.

Genome-wide association study of hepatitis C virus- and cryoglobulin-related vasculitis

The host genetic basis of mixed cryoglobulin vasculitis is not well understood and has not been studied in large cohorts. A genome-wide association study was conducted among 356 hepatitis C virus (HCV) RNA-positive individuals with cryoglobulin-related vasculitis and 447 ethnically matched, HCV RNA-positive controls. All cases had both serum cryoglobulins and a vasculitis syndrome. A total of 899 641 markers from the Illumina HumanOmni1-Quad chip were analyzed using logistic regression adjusted for sex, as well as genetically determined ancestry. Replication of select single-nucleotide polymorphisms (SNPs) was conducted using 91 cases and 180 controls, adjusting for sex and country of origin. The most significant associations were identified on chromosome 6 near the NOTCH4 and MHC class II genes. A genome-wide significant association was detected on chromosome 6 at SNP rs9461776 (odds ratio=2.16, P=1.16E-07) between HLA-DRB1 and DQA1: this association was further replicated in additional independent samples (meta-analysis P=7.1 × 10(-9)). A genome-wide significant association with cryoglobulin-related vasculitis was identified with SNPs near NOTCH4 and MHC Class II genes. The two regions are correlated and it is difficult to disentangle which gene is responsible for the association with mixed cryoglobulinemia vasculitis in this extended major histocompatibility complex region.

Hepatitis C-associated mixed cryoglobulinemic vasculitis induces differential gene expression in peripheral mononuclear cells

This study examines the distinct gene expression profile of peripheral blood mononuclear cells from patients with chronic hepatitis C infection and mixed cryoglobulinemic (MC) vasculitis. Our DNA microarray analysis indicates that hepatitis C virus (HCV)-associated MC vasculitis is characterized by compromised neutrophil function, impaired chemotaxis, and increased interferon-stimulated gene (ISG) expression, contributing to overall MC pathogenesis and end-organ damage. Increased ISG expression is suggestive of an enhanced endogenous interferon gene signature. PBMC depletion assays demonstrate that this increased expression is likely due to an activation of monocytes and not a direct result of B cell expansion. Notably, this monocyte activation of ISG expression in HCV-associated MC vasculitis suggests a poor predictor status of interferon-based treatment. Further analysis of PBMC gene expression profiles before and after in vivo B cell depletion therapy is critical to completely understanding the mechanisms of MC vasculitis pathogenesis.

Purpura with ulcerative skin lesions and mixed cryoglobulinemia in a quiescent hepatitis B virus carrier

Mixed cryoglobulinemia is occasionally seen in patients with hepatitis B virus (HBV) infection. This report presents the case of a quiescent HBV carrier who had type II mixed cryoglobulinemia, protracted purpura, ulcerative skin lesions and advanced chronic kidney disease. The cutaneous manifestations of the patient improved along with a decrease in the serum cryoglobulin and HBV-deoxyribonucleic acid levels following the initiation of oral entecavir in combination with plasmapheresis. However, the patient ultimately required prednisolone due to the limited benefits of these treatments. We also discuss various concerns regarding steroid treatment in patients with mixed cryoglobulinemia complicated by HBV infection.

Cellular targeting in autoimmunity

Many biologic agents that were first approved for the treatment of malignancies are now being actively investigated and used in a variety of autoimmune diseases such as rheumatoid arthritis (RA), antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, systemic lupus erythematosus (SLE), and Sjogren's syndrome. The relatively recent advance of selective immune targeting has significantly changed the management of autoimmune disorders and in part can be attributed to the progress made in understanding effector cell function and their signaling pathways. In this review, we will discuss the recent FDA-approved biologic therapies that directly target immune cells as well as the most promising investigational drugs affecting immune cell function and signaling for the treatment of autoimmune disease.

Treatment of hepatitis C cryoglobulinemia: mission and challenges

Mixed cryoglobulinemia (MC) is a syndrome resulting from cold-insoluble immunoglobulin complexes or cryoglobulins (CGs) that precipitate in the serum of 40% to 50% of patients with chronic hepatitis C virus (HCV) infection. The pathogenesis of cryoglobulinemia likely occurs due to chronic viremia and generation of rheumatoid factor following continuous presentation of antigen-immunoglobulin complexes to B cells. CGs are thought to be responsible for a variety of extrahepatic manifestations associated with HCV, including vasculitis, glomerulonephritis, arthritis, and neuropathies, which occur in approximately 10% of HCV patients with CGs. CGs also are a powerful predictive factor for progressive liver disease and the aggressive reoccurrence of liver disease in HCV-positive patients after liver transplantation. First-line therapy for MC due to HCV infection is antiviral therapy with pegylated interferon-alpha and ribavirin. Viral eradication usually produces marked reduction of physical complications and arrests end organ damage concomitant with clearance of CG. Additional prospective, controlled studies are necessary to determine whether CG influences patient virologic response and/or its durability to antiviral therapy. Immunomodulators such as corticosteroids and cyclophosphamide are efficacious for palliative treatment of the symptomatology of HCV cryoglobulinemia but may enhance viral replication. Consequently, prolonged therapy with immunomodulatory agents should be limited to severe vasculitis or aggressive glomerulonephritis in patients with MC due to HCV who have failed to respond to antiviral therapy. In acute, fulminant presentations, plasmapheresis may provide temporary relief and arrest the rapid progression of the disease so that additional therapy can be initiated.

An unexpected presentation: minimal change disease in an adult with treatment-naïve hepatitis C

Minimal change disease is the most common glomerular disease affecting children; its prevalence among adults, however, is eclipsed by other glomerular pathologies. Each of these diseases has a number of classic associations, such as membranoproliferative glomerulonephritis with hepatitis C. We report the case of a middle-aged African-American male who presented with the nephrotic syndrome and acute renal failure and was concomitantly diagnosed with a new hepatitis C infection. He also had a history of urethral strictures with potential reflux nephropathy, which--in combination with his African-American race--also made focal segmental glomerulosclerosis a diagnostic possibility. Full laboratory evaluation did not distinguish the cause of his massive proteinuria; subsequent renal biopsy ultimately revealed minimal change disease. A full course of high-dose steroids eventually reduced his proteinuria, after which his renal failure resolved as well without need for hemodialysis.

Infectious serologies and autoantibodies in hepatitis C and autoimmune disease-associated mixed cryoglobulinemia

Mixed cryoglobulinemia (MC) syndrome is an immune complex-mediated vasculitis characterized by the clinical triad of purpura, weakness, and arthralgias, the morbidity of which is mainly related to kidney and peripheral nervous system dysfunction as well as to the development of a secondary lymphoma (Ferri et al. Autoimmun Rev 7:114-120, 2007, Lidar et al. Ann N Y Acad Sci 1173:649-657, 2009, Trejo et al. Semin Arthritis Rheum 33:19-28, 2003). MC is associated with infectious and systemic disorders, principally autoimmune and lymphoproliferative diseases. Since the 1990s, a striking association (>90%) between MC and hepatitis C virus (HCV) infection has been established (Ferri and Bombardieri 2004; Pascual et al. J Infect Dis 162:569-570, 1990). However, information regarding the etiopathogenesis of HCV-negative MC is scant (Mascia et al. Dig Liver Dis 39:61-64, 2007). We hereby present our findings, as well as previously published data, regarding the presence of antibodies against infectious agents and autoantibodies in patients with MC in an attempt to establish novel associations which may shed light on the etiopathogenesis of this disease.

A trial of complement inhibition in a patient with cryoglobulin-induced glomerulonephritis

Cryoglobulinemia induces an immune complex-mediated glomerulonephritis that is characterized by the presence of large immune deposits, including complement C3 and C5b-9, marked macrophage influx and mesangial cell proliferation. The precise role of complement in cryoglobulin-induced glomerulonephritis in humans remains unclear, whereas in mice there has been evidence that complement activation might be a central factor favoring glomerular inflammation, particularly by the recruitment of neutrophils. We report on an exceptional case of cryoglobulin-induced glomerulonephritis in a patient with mixed essential cryoglobulinemia type II. The clinical features included relapsing proteinuria and renal function impairment that were controlled by plasmapheresis. Complement was low in plasma and two renal biopsies at 1-year interval showed prominent immunoglobulin and complement deposits, with unusual high numbers of neutrophils. In a 1-patient clinical trial, we tested whether the monoclonal anti-C5 antibody eculizumab would be sufficient to control renal function at the time of a relapse. Although during the initial weeks renal function was stabilized, slow increase in creatinine could not be controlled by this treatment, so that plasmapheresis was reinstituted. This result suggests that despite evidence for a role of complement in enhancing renal damage in this patient, other inflammatory processes dominated.

A randomized controlled trial of rituximab following failure of antiviral therapy for hepatitis C virus-associated cryoglobulinemic vasculitis

OBJECTIVE

To perform a randomized controlled trial of rituximab in patients with hepatitis C virus (HCV)-associated mixed cryoglobulinemic vasculitis.

METHODS

We conducted a single-center, open-label, randomized controlled trial of rituximab (375 mg/ m(2) /week for 4 weeks) compared to the best available therapy (maintenance or increase in immunosuppressive therapy) for HCV-associated cryoglobulinemic vasculitis in patients in whom antiviral therapy had failed to induce remission. The primary end point was disease remission at 6 months from study entry.

RESULTS

A total of 24 patients were enrolled (12 in each treatment group). Baseline disease activity and organ involvement were similar in the two groups. Ten patients in the rituximab group (83%) were in remission at study month 6, as compared with 1 patient in the control group (8%), a result that met the criterion for stopping the study (P < 0.001). The median duration of remission for rituximab-treated patients who reached the primary end point was 7 months. No adverse effects of rituximab on HCV plasma viremia or on hepatic transaminase levels were observed.

CONCLUSION

Rituximab was a well-tolerated and effective treatment in patients with HCV-associated cryoglobulinemic vasculitis in whom antiviral therapy failed to induce remission.

Comparison of cryoglobulinemia in children and adults

BACKGROUND/PURPOSE

Cryoglobulinemic vasculitis is a systemic vasculitis resulting from circulating immune complex deposition in the small vessels and is characterized by variable clinical features, including purpura, Raynaud's syndrome, ulcerations, arthralgia, glomerulonephritis, and peripheral neuropathy. Cryoglobulinemia can also result from hepatitis C virus (HCV) infection. The clinical spectrum and associated or underlying diseases of cryoglobulinemia in different age groups is not well understood. This study investigated the demographic, clinical, serologic features, and associated or underlying diseases in children and adult patients with cryoglobulinemia.

METHODS

The retrospective study included 114 patients (18 children, 96 adults) who presented with cryoglobulinemia between 2000 and 2010 at the Chang Gung Memorial Hospital. Their medical records were reviewed and serological and virologic assessments were analyzed.

RESULTS

In this group of patients, children had a significantly higher prevalence of prolonged fever (16.7% vs. 3.13%; p=0.018), arthralgia (66.67% vs. 16.67%; p<0.001), arthritis (66.67% vs. 15.63%; p<0.001) and cutaneous involvement (77.78% vs. 50%; p=0.03) compared with adults. Both the adult and children groups had a greater frequency of hepatitis B virus (HBV) infection (20.8% and 5.6%, respectively), than HCV infection (12.5% and 0%, respectively).

CONCLUSIONS

Children with cryoglobulinemia had a significantly higher prevalence of prolonged fever, arthralgia, arthritis and cutaneous involvement compared with adults.

Immunological Aspects of Systemic Vasculitis

Primary vasculitis are commonly multifactorial disorders involving environmental, genetic and immunological factors. Several immune-based effector mechanisms are implicated in the vascular wall damage. These effector mechanisms commonly imply auto-antibodies or immune complexes - mediated cytotoxicity but the contribution of a T-cell mediated immune response has also been described, particularly in large vascular vasculitis. Despite advances in understanding the pathophysiological mechanisms of vasculitis, the triggering events initiating the disease remain largely undefined in most cases. This review highlights the recent advances in the etiopathogenesis of primary vasculitis. A better understanding of the immunological aspects of these disorders may provide insight into the development of novel therapeutical strategies.

Rituximab in cryoglobulinaemic vasculitis, evidence for its effectivity: a case report and review of literature

Cryoglobulinaemia associated with systemic vasculitis mediated by immune complexes is a rare combination. These immune complexes are composed of immunoglobulins and precipitate when exposed to cold temperature. Cryoglobulinaemic vasculitis, treated or untreated, may lead to substantial morbidity and even mortality. Novel targeted therapies may well provide new therapeutic options following or perhaps even prior to the classical cytotoxic therapies. Systemic B cell depletion with rituximab, a chimeric monoclonal antibody against CD20 antigen, is commonly applied in patients with non-Hodgkin's lymphoma or in refractory rheumatoid factor-positive rheumatoid arthritis. Since B cell clones are the source of cryoglobulins, therapeutic effectiveness of rituximab in cryoglobulinaemic vasculitis may be expected. We describe a 72-year-old woman with mixed cryoglobulinaemia type 2, who has successfully been treated with rituximab infusions after failing on prednisone and azathioprine. We reviewed the literature and found 142 cases of cryoglobulinaemic vasculitis, 138 mixed (type 2 or 3) and four, type 1. Rituximab was applied mostly after failure on other treatments. Significant reduction in levels of rheumatoid factor, cryoglobulins and IgM were reported after rituximab therapy. Of the total 142, cases 119 could be evaluated for the response on rituximab therapy, the other 23 cases only regarding side effects. Of the 119 evaluated patients, 71 (60%) had complete response; 28 (23%), partial response and 20 patients (17%), no response. Data were not blinded or placebo-controlled. Side effects were seen in 27 of the 142 patients. Occurrence of the side effects was associated with high baseline levels of cryoglobulins, with a high dose of rituximab infusion of 1,000 mg and with a high level of complement activation. Death was reported four times and was related with the disease.

Peripheral blood B cell subset skewing is associated with altered cell cycling and intrinsic resistance to apoptosis and reflects a state of immune activation in chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is associated with B cell activation, although underlying mechanisms are unclear. To investigate B cell regulation during HCV infection, we measured bulk B cell CpG and Staphylococcus aureus Cowan-induced IgG Ab-secreting cell (ASC) frequency, HCV and tetanus-specific ASC frequency, BCR- and CD40L-dependent CD80/CD86 expression, and activation of memory CD4 cells. Immature transitional, naive, resting memory, mature activated, tissue-like memory, and plasma B cell subset frequencies, cell cycling, and intrinsic apoptosis were quantified. We observed intact or enhanced tetanus-specific and total IgG ASC frequency, serum IgG, BCR- and CD40L-dependent CD80/CD86 expression, and CD40L-dependent bulk B cell activation of memory CD4 cells in HCV infection. HCV-specific ASCs were observed in HCV-infected but not control subjects, although frequencies were lower compared with tetanus-specific cells. Immature transitional and mature activated B cell subset frequencies were increased in HCV-infected subjects, with immature transitional frequency associated with liver inflammation and serum B cell-activating factor. Mature activated B cells less commonly expressed Ki67, more commonly expressed Bcl2, and were more intrinsically resistant to apoptosis, whereas immature transitional B cells more commonly expressed Ki67, the latter associated with plasma HCV level. Taken together, these results indicate that in the setting of chronic HCV infection, a state of activation results in B cell subset skewing that is likely the result of alterations in homeostasis, cell cycling, and intrinsic resistance to apoptosis and that results in an overall intact or enhanced B cell response to BCR and CD40L.

Management of hepatitis C virus-related mixed cryoglobulinemia

Mixed cryoglobulinemia is a chronic immune complex-mediated disease strongly associated with hepatitis C virus (HCV) infection. Mixed cryoglobulinemia is a vasculitis of small and medium-sized arteries and veins, due to the deposition of complexes of antigen, cryoglobulin and complement in the vessel walls. The main clinical features of mixed cryoglobulinemia vasculitis include the triad of palpable purpura, arthralgias, and weakness, and other pathological conditions such as glomerulonephritis, peripheral neuropathy, skin ulcers, and widespread vasculitis. The treatment of HCV-related mixed cryoglobulinemia is difficult due to the multifactorial origin and clinical polymorphism of the syndrome. It can be directed to eradicate the HCV infection, suppress the B-cell clonal expansion and cryoglobulin production, or ameliorate symptoms. The choice of the most appropriate treatment is strictly related to the assessment of disease activity, and to the extent and severity of organ involvement.

Treatment in inflammatory neuropathies

This review focuses on recent developments in the treatment of inflammatory neuropathies arising from immune dysregulation, rather than from infectious causes. The dysimmune inflammatory neuropathies are diseases of the peripheral nerves that have varying etiologies and may respond to immunomodulatory therapies. They are characterized by inflammatory changes in the nerve with associated destruction of myelin and axons. The underlying immune mechanisms are better understood in some of these conditions than others. Correct diagnosis and treatment is important to prevent clinical progression. Randomized controlled trials of some treatments in the more common inflammatory neuropathies have clarified their effectiveness; however, there are still groups of patients who are resistant to currently available treatments and for whom little effective treatment is available. Newer, targeted biologics and larger controlled trials of existing and novel therapies in these conditions offer promise of improved morbidity and mortality in this group of diseases.

Prolonged infections associated with antineutrophil cytoplasmic antibodies specific to proteinase 3 and myeloperoxidase: diagnostic and therapeutic challenge

Chronic infections may mimic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). We investigated which markers may help in the diagnosis and the prognosis of infections associated with proteinase 3 (PR3) and myeloperoxidase (MPO)-ANCA. In this study (1993-2008)--with an average follow-up of 5.1 years--we compared 66 AAV patients with 17 PR3 and/or MPO-ANCA-positive patients with protracted bacterial (11/17) or viral (6/17) infections. Seven of 17 patients had subacute bacterial endocarditis (SBE), while six of 17 patients had various autoimmune manifestations of chronic hepatitis C virus (HCV) infection. We determined ANCA, antinuclear antibodies, anti-PR3, anti-MPO, anticardiolipin (aCL), antibeta 2 glycoprotein I (beta2-GP I), cryoglobulins, C3, and C4. Patients with infections were younger than AAV patients (p < 0.01). There was no difference in frequency of renal and skin lesions. AAV patients more frequently had pulmonary and nervous system manifestations (p < 0.01). Patients with infections more frequently had dual ANCA (high PR3, low MPO), aCL, anti-beta2-GP I, cryoglobulins, and hypocomplementemia (p < 0.001). Immunosuppressive therapy (IST) was used in five 17 patients who had persistently high ANCA, cryoglobulinemia, and hypocomplementemia. There was no difference in frequency of lethality and renal failure in the two study groups. In patients who are PR3- and/or MPO-ANCA positive, SBE and HCV infection should be excluded. Although similar in renal and skin manifestations in comparison to AAV, only patients with infections developed multiple serological abnormalities. In patients with infections, concomitant presence of ANCA, cryoglobulins, and hypocomplementemia was associated with severe glomerulonephritis. The serological profile should be repeated after specific antimicrobial or surgical therapy, since some cases might require IST.

Life‐threatening acute pulmonary haemorrhage in primary Sjögren's syndrome with cryoglobulinaemia

We describe a woman with primary Sjögren's syndrome who presented with an acute pulmonary-renal syndrome resulting from cryoglobulinaemic vasculitis. Pulmonary manifestations of Sjögren's syndrome are relatively common, whereas overt pulmonary complications of cryoglobulinaemia are rare. Pulmonary haemorrhage is rare in either disorder. The combination of Sjögren's syndrome, cryoglobulinaemia, and acute pulmonary haemorrhage has not been previously reported.