Prevalence of mixed cryoglobulinaemia syndrome and circulating cryoglobulins in a population-based survey: the Origgio study

Unveiling Mixed Cryoglobulinemia in Suspected Sepsis Without a Source

Cryoglobulinemia is an uncommon condition characterized by the presence of cryoprecipitable immune complexes in circulation, leading to clinical symptoms like purpura, muscle weakness, and joint pain. Specifically, mixed cryoglobulinemia involves the formation of these complexes due to rheumatoid factors, mainly IgM, occasionally IgG or IgA. Previously, Hepatitis C (HCV) was a common cause of mixed cryoglobulinemia, as the chronic HCV infection triggered immune responses that resulted in cryoglobulin formation. However, the emergence of direct-acting antivirals (DAAs) for HCV treatment has shifted the landscape, with autoimmune and lymphoproliferative disorders becoming more prominent etiological factors for mixed cryoglobulinemia. This case report features a 67-year-old woman with a history of Hepatitis C-related cirrhosis. She presented at the emergency department with signs of septic shock and widespread joint pain, particularly in the knees, shoulders, and neck. Effective sepsis management was achieved using antibiotics, albumin infusion, and midodrine. Nonetheless, significant cervical and bilateral knee pain persisted. Further examination uncovered hypocomplementemia and positive results for rheumatoid factors (IgA, IgM, IgG) and cryoglobulin agglutination, confirming the diagnosis of mixed cryoglobulinemia. This case emphasizes the importance of considering mixed cryoglobulinemia in chronic Hepatitis C patients displaying fatigue and joint pain, even in the absence of the traditional clinical manifestations. Moreover, the case underscores the dual benefits of DAA treatment for Hepatitis C in individuals with mixed cryoglobulinemia by achieving viral eradication and alleviating cryoglobulinemia-related symptoms, thus preventing further organ damage.

Cryoglobulinemia: the "cold" problem in cardiac surgery, a single-center experience and a literature review

Cardiac surgery with cardiopulmonary bypass (CBP) is essential for different cardiac procedures in order to perform surgery with a clear sight field.To safely perform surgery with CPB and preserve brain, kidney, and patient tissue from ischemic damage, cold cardioplegia, and mild to deep hypothermia are induced during the operation.Cryoglobulinemia is a hematological/infective-related disease (in certain cases idiopathic) in which temperature-dependent antibodies tend to aggregate and form emboli in the vascular system causing tissue damage if exposed to low temperature.The patient with cryoglobulinemia (known and unknown) can be at risk of a major ischemic event during CPB and induced hypothermia.This article's aim is to evaluate the present scientific literature in order to understand how, in years, the therapeutic or preventive approach, is evolving, and to analyze and make improvements to the management of a cryoglobulinemic patient who must undergo elective or emergency cardiac surgery.In the last part of our article, we expose our single-center experience during a 32-month-long period of survey.In all cases, our medical team (anesthesiologists, perfusionists, and cardiac surgeons) opted for a normothermic cardiopulmonary bypass to lower the risk of cryoglobulin-associated complications.In our experience, along with therapeutic intervention to lower the cryoglobulin titer, normothermic management of cardiopulmonary bypass is as safe as hypothermic management.Notwithstanding our results, further studies with a larger population are needed to confirm this perioperative management in a cardiac surgery setting.

Recent updates in the diagnosis and management of cryoglobulinemic vasculitis

INTRODUCTION

Cryoglobulinemic vasculitis (CV), also known as mixed cryoglobulinemic syndrome (MCS), is a systemic vasculitis that affects small blood vessels. It exhibits a wide range of clinical manifestations, making its treatment a continuing challenge for physicians.

AREAS COVERED

We conducted a comprehensive review to evaluate the current status of diagnosis, management, and treatment of mixed cryoglobulinemia (MC). The accurate clinical and serological evaluation plays a vital role in diagnosing MC, identifying potential comorbidities, and monitoring its main manifestations and complications. Treatment strategies should be individualized based on the underlying etiopathogenesis, the severity of organ involvement, and the associated underlying disease. At present, the two mainstays of CV treatment are direct antiviral agents (for HCV-related CV) and B-cell-targeted therapy.

EXPERT OPINION

MC remains one of the few autoimmune diseases where the etiology is known, at least for the majority of patients. Its pathogenetic mechanism offers a unique opportunity to investigate the interplay between infections and the immune system. Moving forward, the primary challenge will continue to lie in the treatment of resistant or refractory cases of CV, particularly those associated with autoimmune diseases, or cases classified as 'essential' CV.

Proteomic Profiling of Cryoglobulinemia

Objective

We aimed to explore and identify candidate protein biomarkers of cryoglobulinemia (CGE) in disease control patients with negative cryoglobulin (DC) or healthy controls (HCs).

Methods

The tandem mass tag (TMT)-labeled serum quantitative proteomics approach was used to identify differentially expressed proteins between the CGE and DC groups. Ingenuity pathway analysis was used for functional annotation of differentially expressed proteins. Biomarker candidates were validated in another cohort using the parallel reaction monitoring (PRM) method. Apolipoprotein A1 (APOA1), apolipoprotein CIII (APOC3), adiponectin, and proprotein convertase subtilisin/kexin type-9 (PCSK9), which represent key proteins involved in the cholesterol metabolism pathway, were further verified in an increased number of samples by enzyme-linked immunosorbent assay (ELISA).

Results

A total of 1004 proteins were identified, of which 109 proteins were differentially expressed between the CGE and DC groups. These differentially expressed proteins were primarily involved in hepatic fibrosis/hepatic stellate cell activation and immune/inflammation-related pathways. In the disease and biofunction analysis, these proteins were mainly associated with the adhesion of blood cells, leukocyte migration, cholesterol transport, and transport of lipids. Twelve candidate biomarkers were validated by PRM-based proteomics, and proteins involved in the cholesterol metabolism pathway were further verified. APOA1, APOC3, adiponectin and PCSK9 concentrations were increased in CGE patients compared with healthy controls (P=0.0123, 0.1136, 0.5760, and 0.0019, respectively).

Conclusion

This report describes the first application of a TMT-PRM-ELISA workflow to identify and validate CGE-specific biomarkers in serum. APOA1 and PCSK9 have been confirmed to be increased in CGE patients, demonstrating that proteins involved in cholesterol metabolism are also implicated in the development of CGE. These findings contribute to pathogenesis research and biomarker discovery in CGE.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Cryoglobulins Today: Detection and Immunologic Characteristics of 1,675 Positive Samples From 13,439 Patients Obtained Over Six Years

OBJECTIVE

Cryoglobulins are cold-precipitating immunoglobulins. Through progress in techniques, we undertook this study to update information on the biologic characteristics of cryoglobulins in a very large population.

METHODS

A cohort of 13,439 patients was tested for cryoglobulins from January 2010 to December 2016. The analysis included cryoglobulin isotype, clonality, concentration, and IgM rheumatoid factor (IgM-RF) in cryoprecipitate, as well as serum complement and RF. Markers of gammopathy, viral infection, and autoimmunity were also investigated.

RESULTS

Of the 13,439 patients, 1,675 (12.5%) tested positive for cryoglobulins: 155 patients (9.3%) with type I, 788 (47%) with type II, and 732 (43.7%) with type III cryoglobulins. Nine percent of patients who were retested after initially testing negative for cryoglobulins showed a positive result on a follow-up test (196 of the 2,213 retested patients). In type I cryoglobulins, IgM was more frequent but occurred at lower concentrations than IgG. Mixed cryoglobulins were found in 34.8% of the tested patients who were positive for hepatitis C virus and <5% of those who were positive for hepatitis B virus or HIV. Of the patients with anti-double-stranded DNA, anti-SSA, or anti-cyclic citrullinated peptide autoantibodies, 25.4% tested positive for mixed cryoglobulins, with type III occurring more frequently than type II. Both cryoprecipitate and serum were RF-positive in 21.6% of type II and 10.1% of type III cryoglobulins. A decrease of C4, with or without accompanying decreases of C3 and CH50, was found in 23.6% of cryoglobulin samples.

CONCLUSION

Obtained with the use of modern assays, our findings from this very large collection of cryoglobulins provide an update on cryoglobulin distribution and characteristics, with minimal selection bias. Despite strict preanalytical conditions, a negative finding for the presence of cryoglobulin must be confirmed in a second sample. RF activity and complement decreases were rarely detected.

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.

Are direct-acting antivirals safe and effective in hepatitis C virus-cryoglobulinemia? virological, immunological, and clinical data from a real-life experience

OBJECTIVES

Hepatitis C virus (HCV) is the major cause of cryoglobulinemia. Direct-acting antivirals (DAAs) have markedly changed the therapeutic outcomes in the treatment of patients with HCV. We evaluate the efficacy, safety, immunological, and clinical response of different DAA regimens in HCV-cryoglobulinemia.

PATIENTS AND METHODS

Ninety-three cryoglobulinemic patients, divided into symptomatic [symptomatic cryoglobulinemic patients (SCP; n=35)] and asymptomatic [nonsymptomatic cryoglobulinemic patients (NSCP; n=60)], underwent DAAs. Eighty-nine comparable noncryoglobulinemic patients were selected as a control group. We evaluated the sustained virological response (SVR), the adverse effects, and the immune and symptomatic response.

RESULTS

Percentages of patients who achieved SVR and experienced adverse effects were not statistically different between the three groups (100, 95, 93.3% and 57.1, 53.3, 48.3%). In 68.5% of SCP and in 76.7% of NSCP, cryoglobulins disappeared at SVR. No risk factor was associated with the persistence of cryoglobulins. An increase was observed both in C4 (P=0.002; P=0.018) and in C3 (P=0.0037; P=0.031) in SCP and NSCP. About 70% of symptomatic patients showed a complete or partial symptomatic remission: persistence of symptoms is correlated to the type of clinical picture.

CONCLUSION

DAA regimens are safe and effective in patients with HCV-cryoglobulinemia. The achievement of SVR is necessary, but not sufficient, to achieve a complete immunological and clinical response.

Cryoglobulinaemia

Cryoglobulinaemia refers to the serum presence of cryoglobulins, which are defined as immunoglobulins that precipitate at temperatures <37 °C. Type I cryoglobulinaemia consists of only one isotype or subclass of monoclonal immunoglobulin, whereas type II and type III are classified as mixed cryoglobulinaemia because they include immunoglobulin G (IgG) and IgM. Many lymphoproliferative, infectious and autoimmune disorders have been associated with mixed cryoglobulinaemia; however, hepatitis C virus (HCV) is the aetiologic agent in most patients. The underlying mechanism of the disorder is B cell lymphoproliferation and autoantibody production. Mixed cryoglobulinaemia can cause systemic vasculitis, with manifestations ranging from purpura, arthralgia and weakness to more serious lesions with skin ulcers, neurological and renal involvement. This Primer focuses on mixed cryoglobulinaemia, which has a variable course and a prognosis that is primarily influenced by vasculitis-associated multiorgan damage. In addition, the underlying associated disease in itself may cause considerable mortality and morbidity. Treatment of cryoglobulinaemic vasculitis should be modulated according to the underlying associated disease and the severity of organ involvement and relies on antiviral treatment (for HCV infection), immunosuppression and immunotherapy, particularly anti-CD20 B cell depletion therapies.

Apheresis treatment of cryoglobulinemic vasculitis: A multicentre cohort study of 159 patients

OBJECTIVE

To assess the effectiveness of apheresis therapy (AT) in treating the clinical manifestations of patients with complicated cryoglobulinemic vasculitis (CV).

METHODS

A retrospective cohort study of 159 CV patients attending 22 Italian Centers who underwent at least one AT session between 2005 and 2015. The response to AT was evaluated on the basis of a defined grading system.

RESULTS

Peripheral neuropathy was the most frequent clinical condition leading to AT. Therapeutic plasma exchange was used in 70.4% of cases. The outcome of AT was rated very good in 19 cases, good in 64, partial/transient in 40, and absent/not assessable in 36. Life-threatening CV-related emergencies and renal impairment independently correlated with failure to respond to AT. The independent variables associated with an increased risk of death were age at the time of the first AT session, multi-organ life-threatening CV, the presence of renal impairment and failure to respond to AT. The time-dependent probability of surviving until CV-related death in the second year was 84%, with an AHR in patients with absent/not assessable response to AT of 11.25.

CONCLUSION

In this study AT is confirmed to be a safe procedure in patients with CV. Early AT should be considered in patients with severe CV, especially in cases with impending renal involvement, in order to prevent irreversible kidney damage. Although its efficacy in patients with multi-organ failure is limited, AT is the only treatment that can rapidly remove circulating cryoglobulins, and should be considered an emergency treatment.

Efficacy and safety of long-term treatment with low-dose rituximab for relapsing mixed cryoglobulinemia vasculitis

This study aims to evaluate the efficacy and safety of repeated treatments with low-dose rituximab for relapsing mixed cryoglobulinemia vasculitis. Thirty-seven patients with mixed cryoglobulinemia vasculitis refractory to standard of care treatment, 34 of which were HCV-positive, were treated with rituximab at the reduced dosage of 250 mg/m² given twice 1 week apart per cycle. Thirty patients (81%) achieved a clinical response; 5 of them remain in remission, 3 were lost to follow-up or died, and 22 relapsed after a mean of 15.7 months. Eleven relapsers were retreated with one (6 patients), 2 (3 patients), or 3 (2 patients) additional rituximab cycles given at each relapse. Clinical and laboratory efficacy and side effects of long-term treatment were evaluated. Clinical response to retreatment was 91% (10/11) at the first relapse, 80% (4/5) at the second relapse, and 100% (2/2) at the third relapse. The mean (±SD) time to relapse was 17.1 ± 14.1 months in 30 patients who were treated with only one cycle (from first cycle to the first relapse) and 45.7 ± 30.6 months (from first cycle to the last observed relapse) in 11 patients treated with 2 or more cycles (p = 0.0037). Severe adverse reactions occurred in 3 patients, in 2 of whom at the first cycle. Our results suggest that repeated treatment of relapsing mixed cryoglobulinemia with a low-dose rituximab regimen is efficacious, safe, and cost-effective for the long-term management of this disorder.

International diagnostic guidelines for patients with HCV-related extrahepatic manifestations. A multidisciplinary expert statement

Hepatitis C virus (HCV) infection is responsible for both hepatic and extra-hepatic disorders (HCV-EHDs); these latter are correlated on one hand clearly with HCV lymphotropism causing immune-system dysregulation as well as with viral oncogenic potential, and on the other hand probably with chronic inflammatory status causing cardio-metabolic complications as well as neurocognitive disturbances. The spectrum of HCV-EHDs ranges from mild or moderate manifestations, such as arthralgia, sicca syndrome, peripheral neuropathy, to severe, life-threatening complications, mainly vasculitis and neoplastic conditions. Given the clinical heterogeneity of HCV-EHDs, HCV-infected individuals are inevitably referred to different specialists according to the presenting/prevalent symptom(s); therefore, the availability of comprehensive diagnostic guidelines is necessary for a patient's whole assessment that is decisive for early diagnosis and correct therapeutic approach of various hepatic and HCV-EHDs, regardless of the specific competencies of different physicians or referral centers. In this respect, a multidisciplinary network of experts, the International Study Group of Extrahepatic Manifestations Related to Hepatitis C Virus Infection (ISG-EHCV), was organized with the intention to formulate diagnostic guidelines for the work-up of possible HCV-EHDs. There was a broad consensus among ISG-EHCV members on the proposed guidelines, which essentially are based on two main levels of patient's assessment. At the referral stage, it is proposed that all patients with HCV infection should be invariably examined by means of first-line diagnostic procedures including virological and hepatic parameter evaluation, as well as the detection of clinical findings that may suggest one or more HCV-EHDs. This preliminary assessment should reveal specific HCV-EHDs, which will be deeper analyzed by means of second-line, targeted investigations. The proposed multidisciplinary expert statement represents the first attempt to draw comprehensive diagnostic guidelines for HCV-infected individuals encompassing the entire spectrum of HCV-related disorders, namely typical hepatic manifestations along with less common, often unpredictable HCV-EHDs. The HCV-EHDs may compromise to a substantial degree the overall disease outcome in a significant number of HCV-infected individuals that renders their timely identification and treatment an imperative. In conclusion, the application of standardized but thorough diagnostic guidelines of HCV-EHDs is advisable at the referral stage as well as during the follow-up period of HCV infected patients. It is envisioned that the proposed strategy will result in improvement of clinical outcomes in such patients.

Autoimmunity in 2014

Our PubMed search for peer-reviewed articles published in the 2014 solar year retrieved a significantly higher number of hits compared to 2013 with a net 28 % increase. Importantly, full articles related to autoimmunity constitute approximately 5 % of immunology articles. We confirm that our understanding of autoimmunity is becoming a translational paradigm with pathogenetic elements rapidly followed by new treatment options. Furthermore, numerous clinical and pathogenetic elements and features are shared among autoimmune diseases, and this is well illustrated in the recent literature. More specifically, the past year witnessed critical revisions of our understanding and management of antiphospholipid syndrome with new exciting data on the pathogenicity of the serum anti-beta2 glycoprotein autoantibody, a better understanding of the current and new treatments for rheumatoid arthritis, and new position papers on important clinical questions such as vaccinations in patients with autoimmune disease, comorbidities, or new classification criteria. Furthermore, data confirming the important connections between innate immunity and autoimmunity via toll-like receptors or the critical role of T regulatory cells in tolerance breakdown and autoimmunity perpetuation were also reported. Lastly, genetic and epigenetic data were provided to confirm that the mosaic of autoimmunity warrants a susceptible individual background which may be geographically determined and contribute to the geoepidemiology of diseases. The 2014 literature in the autoimmunity world should be cumulatively regarded as part of an annus mirabilis in which, on a different level, the 2014 Annual Meeting of the American College of Rheumatology in Boston was attended by over 16,000 participants with over selected 3000 abstracts.

[Renal involvement during type 1 cryoglobulinemia]

Cryoglobulins are circulating immunoglobulins that precipitate with cold temperature and dissolve with rewarming. Type 1 cryoglobulinemia is composed of a single monoclonal immunoglobulin and is associated with renal involvement in up to 40% of cases. Type 1 cryoglobulinemia is related to an underlying B-cell haematological malignancy in 60% of patients. In the remaining cases, in the absence of criteria for malignancy, the diagnosis of monoclonal gammopathy of renal significance should be established. The clinical and biological setting and histological features of type 1 cryoglobulinemia are globally similar to those of mixed cryoglobulinemia. In case of haematological malignancy, the treatment is guided by the nature of the underlying disease, and aims at inducing haematological remission, which is necessary for the renal response. The management of monoclonal gammopathy of renal significance has been clarified by an international consensus group and is based on the nature of the underlying clone. In case of monoclonal cryoglobulinemia associated with a plasma-cell clone (IgG or IgA), the treatment is based on the combination of bortezomib, cyclophosphamide and dexamethasone. In case of IgM monoclonal cryoglobulinemia, the treatment is similar to that of Waldenström macroglobulinemia, and is based on rituximab. The clinical course of renal monoclonal cryoglobulinemia is intimately associated with the haematological response, and is usually favourable.

Long term outcome of patients with low level of cryoglobulin (<0.05g/L)

OBJECTIVES

To date, no studies have yet assessed the characteristics of non-HCV patients with low level of cryoglobulin (≤0.05 g/L). The aims of the current study were thus to: 1) determine the prevalence of cryoglobulin ≤0.05 g/L in patients with non-HCV cryoglobulin; and 2) compare clinical features and long term outcome, including organ complications and mortality rate, between non-HCV patients with cryoglobulin level ≤0.05 g/L and those exhibiting cryoglobulin level >0.05 g/L.

METHODS

Among 6379 cryoglobulin testing, cryoglobulin was detected in 618 patients (9.69% of cases); of these 618 patients, 453 non-HCV patients were included in the study. The medical records of these patients were reviewed.

RESULTS

Of the 453 non-HCV cryoglobulin-positive patients, 265 (58.6%) exhibited cryoglobulin level ≤0.05 g/L. We showed that patients with cryoglobulin level ≤0.05 g/L had: 1) less commonly: palpable purpura (p<0.001), digital ulcers (p=0.006), peripheral neurologic involvement (p=0.03) and renal impairment (p=0.03); and 2) lower median values of ESR (p<0.001) and C-reactive protein (p=0.001). The patients with cryoglobulin level ≤0.05 g/L less often experienced infections (p=0.04) and hematological malignancies (p=0.01); both groups did not differ regarding prevalence of connective tissue diseases and solid tumors. Mortality rate was as high as 13.6% in patients with cryoglobulin level ≤0.05 g/L; death was mainly due to: solid tumors (16.6%), cardiovascular complications (13.8%), hematological malignancies (11.1%), infections (8.3%), pulmonary/renal complications of cryoglobulin (8.3%) and connective tissue diseases (8.3%).

CONCLUSION

Our study shows a high prevalence of cryoglobulin level ≤0.05 g/L in clinical practice. Our findings further underscore that non-HCV cryoglobulin level ≤0.05 g/L may be responsible for severe renal and neurological complications, leading to high morbidity and mortality in these patients. Thus, our data suggest that both appropriate therapy and close follow-up may be required to improve such patients' outcome.

Efficacy of low-dose rituximab for the treatment of mixed cryoglobulinemia vasculitis: Phase II clinical trial and systematic review

OBJECTIVE

To evaluate whether rituximab at a low dose of 250 mg/m(2) × 2 may be as effective as at higher dosages, most commonly 375 mg/m(2)×4, used in previous studies on the treatment of patients with refractory mixed cryoglobulinemia (MC) vasculitis associated with hepatitis C virus (HCV) infection.

METHODS

We conducted a phase 2, single-arm two-stage trial (EUDRACT n. 2008-000086-38) of low-dose rituximab in 52 patients with HCV-associated MC who were ineligible/intolerant or non-responder to antiviral therapy. The primary outcomes were response of vasculitis evaluated by the Birmingham Vasculitis Activity Score (BVAS) at months 3, 6 and 12, rate of relapses and time to relapse, and rate of adverse events. Our data were compared with those reported in 19 published studies selected among 291 reviewed in a literature search.

RESULTS

The cumulative response rate (complete and partial) at month 3 was 81% in our patients, and 86% in 208 patients from studies using high-dose rituximab. The relapse rate and median time to relapse were, respectively, 41% and 6 months in our study, and 32% and 7 months in high-dose studies. Treatment-related adverse events were 11.5% in our study and 19.9% in high-dose studies. None of these differences was statistically significant.

CONCLUSION

Rituximab at a low dosage of 250 mg/m(2) × 2 is as effective as at higher dosages for treating MC vasculitis. This low-dose regimen may improve the cost/benefit profile of rituximab therapy for MC.

Vasculitis with renal involvement in essential mixed cryoglobulinemia: Case report and mini-review

The discovery of a strong association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia (MC) has led to an increasingly rare diagnosis of idiopathic essential MC (EMC). The incidence of EMC is high in regions where there is a comparatively low HCV infection burden and low in areas of high infection prevalence, including HCV. The diagnosis of EMC requires an extensive laboratory investigation to exclude all possible causes of cryoglobulin formation. In addition, although cryoglobulin testing is simple, improper testing conditions will result in false negative results. Here, we present a 46-year-old female patient with a case of EMC with dermatological and renal manifestations, highlighting the importance of extensive investigation to reach a proper diagnosis. We review the need for appropriate laboratory testing, which is often neglected in clinical practice and which can result in false negative results. This review also emphasizes the significance of an extended testing repertoire necessary for better patient management. Despite a strong association of MC with HCV infection and other causes that lead to cryoglobulin formation, EMC remains a separate entity. Correct diagnosis requires proper temperature regulation during sample handling, as well as characterization and quantification of the cryoprecipitate. Inclusion of rheumatoid factor activity and complement levels in the cryoglobulin test-panel promotes better patient management and monitoring. Consensus guidelines should be developed and implemented for cryoglobulin detection and the diagnosis of cryoglobulinemic syndrome, which will reduce variability in inter-laboratory reporting.