Clinical and clonal characteristics of monoclonal immunoglobulin M-associated type I cryoglobulinaemia.

Monoclonal immunoglobulin M-associated type I cryoglobulinaemia is poorly characterised. We screened 534 patients with monoclonal IgM disorders over a 9-year period and identified 134 patients with IgM type I cryoglobulins. Of these, 76% had Waldenström macroglobulinaemia (WM), 5% had other non-Hodgkin lymphoma (NHL) and 19% had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinically relevant IgM-associated disorders (including cold agglutinin disease [CAD], anti-MAG antibodies, amyloidosis and Schnitzler syndrome) coexisted in 31%, more frequently in MGUS versus WM/NHL (72% vs. 22%/29%, p < 0.001). The majority of those with cryoglobulins and coexistent CAD/syndrome had the molecular characteristics of a CAD clone (wild-type MYD88 in 80%). A half of all patients had active manifestations at cryoglobulin detection: vasomotor (22%), cutaneous (16%), peripheral neuropathy (22%) and hyperviscosity (9%). 16/134 required treatment for cryoglobulin-related symptoms alone at a median of 38 days (range: 6-239) from cryoglobulin detection. At a median follow-up of 3 years (range: 0-10), 3-year cryoglobulinaemia-treatment-free survival was 77% (95% CI: 68%-84%). Age was the only predictor of overall survival. Predictors of cryoglobulinaemia-related treatment/death were hyperviscosity (HR: 73.01; 95% CI: 15.62-341.36, p < 0.0001) and cutaneous involvement (HR: 2.95; 95% CI: 1.13-7.71, p = 0.028). Type I IgM cryoglobulinaemia is more prevalent than previously described in IgM gammopathy and should be actively sought.

Cutaneous vasculitis occurring in the setting of systemic lupus erythematosus: a multicentre cohort study.

OBJECTIVES: To describe the clinical and pathological features of biopsy-proven cutaneous vasculitis (CV) associated with SLE, focusing on diagnosis classification and impact on overall SLE activity. METHODS: Retrospective multicentric cohort study including SLE patients with biopsy-proven CV identified by (i) data from pathology departments of three university hospitals and (ii) a national call for cases. SLE was defined according to 1997 revised ACR and/or 2019 ACR/EULAR criteria. CV diagnosis was confirmed histologically and classified by using the dermatological addendum of the Chapel Hill classification. SLE activity and flare severity at the time of CV diagnosis were assessed independently of vasculitis items with the SELENA-SLEDAI and SELENA-SLEDAI Flare Index. RESULTS: Overall, 39 patients were included; 35 (90%) were female. Cutaneous manifestations included mostly palpable purpura (n = 21; 54%) and urticarial lesions (n = 18; 46%); lower limbs were the most common location (n = 33; 85%). Eleven (28%) patients exhibited extracutaneous vasculitis. A higher prevalence of Sjögren's syndrome (51%) was found compared with SLE patients without CV from the French referral centre group (12%, P < 0.0001) and the Swiss SLE Cohort (11%, P < 0.0001). CV was mostly classified as urticarial vasculitis (n = 14, 36%) and cryoglobulinaemia (n = 13, 33%). Only 2 (5%) patients had no other cause than SLE to explain the CV. Sixty-one percent of patients had inactive SLE. CONCLUSION: SLE-related vasculitis seems very rare and other causes of vasculitis should be ruled out before considering this diagnosis. Moreover, in more than half of patients, CV was not associated with another sign of active SLE.

Bartonella and Coxiella infections presenting as systemic vasculitis: case series and review of literature.

OBJECTIVES: Coxiella and Bartonella spp. display particular tropism for endothelial or endocardial tissues and an abnormal host response to infections with induced autoimmunity. We aimed, through a case series combined with a comprehensive literature review, to outline characteristics of Coxiella and Bartonella infections presenting as systemic vasculitis. METHODS: We retrospectively included cases of definite Coxiella and Bartonella infections presenting with vasculitis features and performed a comprehensive literature review. RESULTS: Six cases of Bartonella infections were added to 18 cases from literature review. Causative pathogens were mainly B. henselae. Bartonella infection mimicked ANCA-associated vasculitis in 83% with PR3-ANCA and presented as cryoglobulinaemic vasculitis in 8%. GN was present in 92%, and 88% had endocarditis. Complement fractions were low in 82% and rheumatoid factor positive in 85%. Kidney biopsies showed cell proliferation, mostly crescentic, with pauci-immune GN in 29%. Outcome was favourable, with the use of antibiotics alone in one-third. Five cases of Coxiella infections were added to 16 from literature review. Sixteen had small-vessel vasculitides, mainly cryoglobulinaemia vasculitis in 75%. One patient had polyarteritis nodosa-like vasculitis and four large-vessel vasculitis. Outcome was good except for one death. A highly sensitive next generation sequencing analysis on three Coxiella- and two Bartonella-related vasculitides biopsies did not find any bacterial DNA. CONCLUSION: Coxiella and Bartonella are both able to induce vasculitis but display distinct vasculitis features. Bartonella mimics PR3-ANCA-associated vasculitis in the setting of endocarditis, whereas Coxiella may induce vasculitis involving all vessel sizes.

PDCD1 and IFNL4 genetic variants and risk of developing hepatitis C virus-related diseases.

BACKGROUND: Genetic variants of IFNL4 and PDCD1 genes have been shown to influence the spontaneous clearance of hepatitis C virus (HCV) infection. We investigated the IFNL4 rs12979860 and the PDCD1 polymorphisms in 734 HCV-positive patients, including 461 cases with liver disease of varying severity and 273 patients with lymphoproliferative disorders to determine the association of these genes with patient's outcome. METHODS: Expression levels of PDCD1 mRNA encoded by haplotypes were investigated by quantitative PCR in hepatocellular carcinoma (HCC) tissue and peripheral blood mononuclear cells. Flow cytometry was used to detect PD-1 and its ligand PD-L1. RESULTS: The frequency of IFNL4 rs12979860 C/T or T/T genotypes was significantly higher in patients with HCV-related diseases than blood donors (P < .0001). Patients expressing the IFNλ4 variant with one amino acid change that reduces IFNλ4 secretion was found increased in frequency in HCV-related diseases compared to HCC PDCD1 mRNA levels in HCC tissue were significantly higher in cases carrying the PD-1.3 A or the PD-1.7 G allele (P = .0025 and P = .0167). Linkage disequilibrium (LD) between PD-1.3 and IFNL4 was found in patients with mixed cryoglobulinaemia (MC) only (LD = 0 in HCC; LD = 72 in MC). PBMCs of MC patients expressed low levels of PD-L1 in CD19+IgM+B cells and of PD-1 in CD4+T cells suggesting the involvement of regulatory B cell-T cell interaction to the pathogenesis of MC. CONCLUSION: Collectively, our data indicate an important contribution of IFNλ4 expression to the development of HCV-related HCC and an epistatic contribution of IFNL4 and PDCD1 in MC. LAY SUMMARY: Studies of IFNL4 and PDCD1 genes are helpful to better understand the role of host genetic factors and immune antigens influencing the outcome of HCV-related diseases. Our data support an association between the expression of IFNλ4, which prevents the expression of IFNλ3, with all the different HCV-related diseases studied, and besides, evidence that a higher IFNλ4 expression is associated with hepatocellular at a younger age. The expression pattern of low PD-L1 on B cells and high PD-1 on CD4+T-cells in patients with HCV-positive cryoglobulinaemia suggests a critical role of the PD-1/PD-L1 signaling in modulating B cell-T cell interaction in this lymphoproliferative disease.

Direct-acting antiviral agents for hepatitis C virus-mixed cryoglobulinaemia: dissociated virological and haematological responses.

The hepatitis C virus-positive (HCV+) mixed cryoglobulinaemia (MC) is associated with haematological alterations such as monoclonal B-cell lymphocytosis or non-Hodgkin lymphomas (NHLs). Antiviral therapy for MC, based on interferon and ribavirin, has been shown to be able to eliminate the viral replication as well as the B-cell monoclonal alterations. Many studies have reported the efficacy of direct-acting antivirals (DAAs) in the treatment of HCV+ MC. However, some authors noticed the persistence of haematological diseases despite HCV eradication. To verify the effects of DAAs on B-cell proliferation, we evaluated 67 patients with HCV+ MC. Six patients had an overt NHL and 30% had monoclonal B-lymphocytosis. In 20% of the patients, the mutation L265P of the myeloid differentiation factor 88 (MYD88) gene was detected in peripheral blood. All patients had negative HCV viraemia at week 12; one had a breakthrough, while two cases relapsed. A complete clinical response of vasculitis was seen in 60% of the patients. Among the six patients with NHL, one showed a complete response, whereas in the others there were no changes in the number and size of the nodes. Among the patients carrying a clonal population in peripheral blood, only 22% became negative. These data indicate that DAAs are not able to eliminate the clonal alterations induced by HCV in a large proportion of cases.

Serum immunoglobulin free light chain levels in systemic autoimmune rheumatic diseases.

Several reports have highlighted the abnormal increments of serum immunoglobulin free light chains (FLCs) in the course of systemic autoimmune rheumatic diseases (SARD), but a comparative analysis among different conditions is still lacking. A strong association between elevated FLC and hepatitis C virus (HCV)-related mixed cryoglobulinaemia (HCVMC) has been well established. Here, we aimed to analyse serum FLC levels in patients with four different SARD in comparison with HCVMC. Using a turbidimetric assay, free κ and λ chains were quantified in sera from 198 SARD patients (37 rheumatoid arthritis, RA; 47 systemic lupus erythematosus, SLE; 52 anti-phospholipid syndrome, APS; 62 primary Sjogren's syndrome, pSS), 62 HCVMC and 50 healthy blood donors (HD). All patient groups showed increased κ levels when compared to HD: 33·5 ± 2·6 mg/l in HCVMC, 26·7 ± 2·3 mg/l in RA, 29·7 ± 1·9 mg/l in SLE, 23·8 ± 1·1 mg/l in APS, 24·2 ± 1·1 mg/l in pSS; 10·1 ± 0·6 mg/l in HD. Free λ levels displayed a significant increase only for HCVMC (20·4 ± 1·4 mg/l) and SLE (18·4 ± 1·0 mg/l) compared to HD (13·6 ± 0·9 mg/l). The increase of κ compared to λ takes into account a κ /λ ratio of 1·6 for all groups. Our results substantially analyse and strengthen the association between FLC and SARD focusing the questions regarding their role in the pathogenesis and diagnosis of human diseases. Unfortunately, the biochemical differences distinguishing normal from pathological FLC have not been identified. Production of different isotypes is probably connected to still-unknown pathways.

Noninfectious mixed cryoglobulinaemic glomerulonephritis and monoclonal gammopathy of undetermined significance: a coincidental association?

BACKGROUND: Cryoglobulins are cold-precipitable immunoglobulins that may cause systemic vasculitis including cryoglobulinaemic glomerulonephritis (CGN). Type 1 cryoglobulins consist of isolated monoclonal immunoglobulin (mIg), whereas mixed cryoglobulins are typically immune complexes comprising either monoclonal (type 2) or polyclonal (type 3) Ig with rheumatoid activity against polyclonal IgG. Only CGN related to type 1 cryoglobulins has been clearly associated with monoclonal gammopathy of undetermined significance (MGUS) using the conventional serum-, urine- or tissue-based methods of paraprotein detection. CASE PRESENTATION: We present four patients with noninfectious mixed (type 2 or 3) CGN and MGUS. Two patients had type 2 cryoglobulinaemia, one had type 3 cryoglobulinaemia, and one lacked definitive typing of the serum cryoprecipitate. The serum monoclonal band was IgM-κ in all four cases. Treatments included corticosteroids, cyclophosphamide, plasma exchange, and rituximab. At median 3.5 years' follow-up, no patient had developed a haematological malignancy or advanced chronic kidney disease. Other potential causes of mixed cryoglobulinaemia were also present in our cohort, notably primary Sjögren's syndrome in three cases. CONCLUSION: Our study raises questions regarding the current designation of type 2 CGN as a monoclonal gammopathy of renal significance, and the role of clonally directed therapies for noninfectious mixed CGN outside the setting of haematological malignancy.

Type-I Cryoglobulinaemia Associated to Monoclonal Gammapathy of Undetermined Significance.

Cryoglobulins are immunoglobulins that undergo reversible precipitation at cold temperatures. Monoclonal type-I cryoglobulinaemia is the least frequent and is associated to hematological diseases such as multiple myeloma, Waldenström's macroglobulinaemia, chronic lymphocytic leukaemia and lymphoma. We describe the case of a 60-year-old female patient, who suffered from burning pain in her feet for ten months before her admission. The patient presented intermittent distal cyanosis that progressed to digital ischaemia. She also reported paresthesia in her hands, difficulty in writing, and a 26-kg-weight loss. At the physical examination, it was identified livedo reticularis, palpable purpura, and painful ecchymotic lesions in her calves and feet. Moreover, peripheral pulses were palpable and symmetrical. It was observed an atrophy of the right first dorsal interosseous and both extensor digitorum brevis, as well as a distal bilateral apalesthesia and allodynia. Both Achilles reflexes were absent. Laboratory tests revealed anemia, high erythrosedimentation rate and C-reactive protein. Serum protein electrophoresis showed a monoclonal IgG-Kappa gammopathy. The results also evidenced the presence of Bence-Jones proteinuria. The bone marrow biopsy revealed less than 10% of plasma cells, and skin biopsy informed leukocytoclastic vasculitis. The patient was treated with high-dose intravenous steroids and cyclophosphamide. The treatment showed that the skin lesions had improved, pain disappeared and motor deficit stopped its progression.

Long-lasting persistence of large B-cell clones in hepatitis C virus-cured patients with complete response of mixed cryoglobulinaemia vasculitis.

BACKGROUND & AIMS: Hepatitis C virus (HCV)-related mixed cryoglobulinaemia vasculitis (MCV) is characterized by the expansion of rheumatoid factor-producing B-cell clones. The aim of this study was to assess whether B-cell clones may persist in these patients after the clearance of the virus with antiviral therapy, and whether their persistence influences clinical outcomes. METHODS: Forty-five HCV-cured MCV patients were followed up for a median of 18.5 (range 9-38) months after the clearance of HCV. Circulating B-cell clones were detected using flow cytometry either by the skewing of kappa/lambda ratio or by the expression of a VH 1-69-encoded idiotype. RESULTS: The clinical response of vasculitis was 78% complete, 18% partial and 4% null. However, cryoglobulins remained detectable in 42% of patients for more than 12 months. Circulating B-cell clones were detected in 18 of 45 patients, and in 17 of them persisted through the follow-up; nine of the latter patients cleared cryoglobulins and had complete response of vasculitis. Several months later, two of these patients had relapse of MCV. CONCLUSIONS: B-cell clones persist in MCV patients long after HCV infection has been cleared but halt the production of pathogenic antibody. These 'dormant' cells may be reactivated by events that perturb B-cell homeostasis and can give rise to the relapse of cryoglobulinaemic vasculitis.

HCV RNA Genomic sequences and HCV-E2 glycoprotein in sural nerve biopsies from HCV-infected patients with peripheral neuropathy.

AIMS: Peripheral neuropathy (PN), the major neurological complication of chronic HCV infection, is frequently associated with mixed cryoglobulinaemia (MC) and small-vessel systemic vasculitis. While humoral and cell-mediated immune mechanisms are suspected to act together in an aberrant immune response that results in peripheral nerve damage, the role of HCV remains largely speculative. The possible demonstration of HCV in peripheral nerve tissue would obviously assume important pathogenic implications. METHODS: We studied sural nerve biopsies from 11 HCV-positive patients with neuropathic symptoms: five with and six without MC. In situ hybridization (ISH) and immunofluorescence studies were carried out to detect genomic and antigenomic HCV RNA sequences and HCV-encoded E2-glycoprotein, respectively. RESULTS: Epineurial vascular deposits of E2-glycoprotein were found in four (80%) MC and in two (33.3%) non-MC patients, respectively. These findings were enhanced by the perivascular deposition of positive-, though not negative-strand replicative RNA, as also found in the nerve extracts of all patients. Mild inflammatory cell infiltrates with no deposits of immunoglobulins and/or complement proteins were revealed around small vessels, without distinct vasculitis changes between MC and non-MC patients. CONCLUSIONS: These results indicate that nerve vascular HCV RNA/E2 deposits associated to perivascular inflammatory infiltrates were similar in chronically HCV-infected patients, regardless of cryoglobulin occurrence. Given the failure to demonstrate HCV productive infection in the examined sural nerve biopsies, nerve damage is likely to result from virus-triggered immune-mediated mechanisms.

A multicentre study of 95 biopsy-proven cases of renal disease in primary Sjögren's syndrome.

OBJECTIVE.: Renal involvement is a rare event during primary SS (pSS). We aimed to describe the clinico-biological and histopathological characteristics of pSS-related nephropathy and its response to treatment. METHODS.: We conducted a French nationwide, retrospective, multicentre study including pSS patients fulfilling American-European Consensus Group criteria or enlarged American-European Consensus Group criteria, and with biopsy-proven renal involvement. RESULTS.: A total of 95 patients were included (median age 49 years). An estimated glomerular filtration rate (eGFR) of <60 ml/min was found in 82/95 patients (86.3%). Renal biopsy demonstrated tubulointerstitial nephritis (TIN) in 93 patients (97.9%), and frequent (75%) plasma cell infiltrates. Glomerular lesions were found in 22 patients (23.2%), mainly related to cryoglobulin. The presence of anti-SSA (76.8%) and anti-SSB (53.8%) antibodies was particularly frequent among patients with TIN and was associated with a worse renal prognosis. Eighty-one patients (85.3%) were treated, with CSs in 80 (98.8%) and immunosuppressive agents (mostly rituximab) in 21 cases (25.9%). Despite marked interstitial fibrosis at initial biopsy, kidney function improved significantly during the 12-month period following diagnosis (final eGFR 49.9 vs 39.8 ml/min/1.73 m 2 at baseline, P < 0.001). No proven benefit of immunosuppressive agents over steroid therapy alone was found in this study. CONCLUSION.: Renal involvement of pSS is mostly due to TIN with marked T, B and especially plasma cell infiltration. Renal dysfunction is usually isolated but can be severe. Use of CSs can improve the eGFR, but further studies are needed to define the best therapeutic strategy in this disease.

Effectiveness and cost of hepatitis C virus cryoglobulinaemia vasculitis treatment: From interferon-based to direct-acting antivirals era.

BACKGROUND: The net benefits of new hepatitis C virus (HCV) direct-acting antiviral drugs (DAA) in patients with cryoglobulinaemia vasculitis (CryoVas) are unknown. OBJECTIVE: To analyse the effectiveness and cost of all treatments used for HCV-CryoVas in the DAA vs pre-DAA era. METHODS: A chart review of all HCV-CryoVas patients who received antivirals from 1993 to 2016 in a tertiary centre was performed. Treatment effectiveness was analysed for clinical, immunological and virological responses. Cost analyses included anti-HCV treatments, non-antiviral drugs, plasmapheresis, dialysis and hospitalizations. We compared main data in the pre-DAA vs DAA period. RESULTS: About 201 HCV-CryoVas patients were included (women, 53.2%; mean age, 59.2 years; Metavir score F3-F4, 36.7%; genotype 1, 64.2%). Patients in the DAA era (n=27) compared to those in the pre-DAA era (n=174) showed higher rates of clinical (96.3% vs. 78.6%), immunological (89.5% vs. 77.1%), and sustained virological response (75.0% vs. 42.8%). Death rate was 14.8% vs. 24.4% respectively. In the DAA compared to pre-DAA era, mean cost of anti-HCV drugs increased from 11 855 to 57 632 € while mean CryoVas-related cost decreased for both hospitalizations (from 33 510 to 21 347€) and non-antiviral treatments (from 17 347 to 11 397€). CONCLUSION: Improved antiviral efficacy of HCV drugs in the DAA era led to increased clinical and immunological efficacy and a lower death rate. Use of DAAs was associated to higher costs for HCV drugs while costs related to both hospitalizations and non-antiviral treatments decreased.

Cryoglobulinaemic glomerulonephritis: artefacts associated with laboratory diagnosis and need for renal biopsy.

Cryoglobulinemia as a cause of renal impairment is uncommon but needs to be considered in viral hepatitis and haematological malignancies. Often detection and estimation of cryoglobulins are confounded by collection and processing errors. This report highlights the need for stringent processing measures if the clinical suspicion is high.

Clinical and morphologic spectrum of renal involvement in patients with HBV-associated cryoglobulinaemia.

AIM: Cryoglobulinaemic glomerulonephritis related to hepatitis B virus (HBV) infection has been rarely reported. The aim of this study was to investigate the clinical features, renal biopsy findings in patients with HBV-associated cryoglobulinaemia. METHODS: Twelve patients with HBV-associated cryoglobulinaemia were identified in this study. The demographic, clinical, pathological characteristics, treatment and follow-up data were analyzed. RESULTS: Renal involvement was characterized by nephrotic range proteinuria with microscopic haematuria in all patients, and impaired renal function in nine patients (75%). Purpuric rash was the main extrarenal manifestation (58.3%). Type II cryoglobulinaemia was presented in three patients and type III in nine patients. Hypocomplementaemia and positive of rheumatoid factors were present in all patients. Membranoproliferative glomerulonephritis (MPGN) was observed in all kidney specimens. Seven patients also had evidence of prominent cryoglobulins thrombi on renal biopsy, but only three patients had HBV antigen deposits in renal tissues. Antiviral and steroids or immunosuppressive agents have been used in most of patients. During follow-up, two patients died, and four reaching end-stage renal disease; three patients had complete remission, and three patients had renal function improved after therapy. CONCLUSIONS: Nephrotic syndrome with haematuria and renal insufficiency are the main clinical manifestation; cryoglobulinaemic glomerulonephritis are the main renal lesion in patients with HBV-Associated cryoglobulinaemia; half of patients have poor outcome even with antiviral and immunosuppressive therapy. The results of this study indicate that cryoglobulins should be detected in hepatitis B virus-Associated nephropathy in endemic area.

Development of new extra-glandular manifestations or associated auto-immune diseases after establishing the diagnosis of primary Sjögren's syndrome : A long-term study of the Antonius Nieuwegein Sjögren (ANS) cohort.

To investigate in a long-term study, the development of new extra-glandular manifestations (EGM) or associated auto-immune diseases (AID) from 1 year after establishing the diagnosis of primary Sjögren's syndrome (pSS). The primary goal was to examine the frequency and type of these manifestations and to find out which demographic, clinical and serological profile was most at risk. All outpatients diagnosed with primary Sjögren's syndrome were included in a retrospective study, with at least one check-up per year, from June 1991 until August 2015. Patients also fulfilling the criteria for concomitant connective tissue disorders were excluded. Data were collected with respect to the cumulative prevalence of a new EGM or associated AID. 140 patients were included in the final analysis. After 10 years of follow-up, the cumulative incidence of a new EGM or associated AID was 30.7%. The most frequent events were polyneuropathy, interstitial lung disease, (poly)arthritis, discoid lupus erythematosus (LE)/subacute cutaneous LE and Hashimoto's disease. Non-Hodgkin lymphoma was not diagnosed during the follow-up. Patients without chronic benign pain syndrome (CBP) (HR 2.13; 95% CI [0.94-4.76]; p = 0.061), but in particular those with cryoglobulins (HR 2.87; 95% CI [1.20-6.86]; p = 0.013), developed more events. Age at diagnosis, gender, the presence of ANA, anti-Ro/SSA, anti-La/SSB, IgM-RF, decreased levels of C3 or C4, or hypergammaglobulinaemia did not show any statistically significant differences. The burden of disease in pSS is higher than expected due to the development of EGM or associated AID. Therefore, we recommend long-term follow-up of all pSS patients, particularly those with cryoglobulinaemia.

[Extrahepatic manifestations in chronic hepatitis C infected patients]. / Extrahepaticus manifesztációk idült hepatitis C-vírus-fertozöttekben.

The importance of chronic hepatitis C infection is significant. 3% of the World's population is infected. There is at least one extrahepatic manifestation in 50% of HCV patients, which makes the prognosis and mortality worse. The pathomechanisms included are cryoglobulin production, immunmechanisms, and direct viral effects. The authors summarize the main extrahepatic manifestations, as well as treatment possibilities. The aim is to draw attention to this colourful infection in order to improve the recognition in the era of the new effective direct antiviral agents. Orv. Hetil., 2017, 158(16), 603-612.

Cryoglobulinaemic vasculitis at diagnosis predicts mortality in primary Sjögren syndrome: analysis of 515 patients.

OBJECTIVE: To evaluate the fulfilment of classification criteria for cryoglobulinaemic vasculitis (CV) at diagnosis in a large cohort of patients with primary SS and their correlation with poor outcomes. METHODS: We included 515 consecutive patients tested for serum cryoglobulins who fulfilled the 2002 classification criteria for primary SS. CV classification criteria and serum cryoglobulins at diagnosis were assessed as predictors of death and lymphoma using Cox proportional-hazards regression analysis adjusted for age and gender. RESULTS: Positive serum cryoglobulins were detected in 65 (12%) patients, of whom 21 (32%) fulfilled CV classification criteria. Compared with patients positive for cryoglobulins who did not fulfil CV criteria, patients with CV had a higher frequency of type II cryoglobulinaemia (86% vs 43%, P = 0.04), a higher mean cryocrit level (6.58% vs 1.25%, P < 0.001) and a higher cumulated mean EULAR-SS disease activity index score (35.3 vs 16.2, P < 0.001). After a mean follow-up of 110 months, 45 (9%) patients developed B-cell lymphoma and 33 (6%) died. Compared with patients without cryoglobulins, patients with cryoglobulins who fulfilled [hazard ratio (HR) = 7.47, 95% CI: 3.38, 16.53] and did not fulfil (HR = 2.56, 95% CI: 1.03, 6.35) CV criteria both showed a higher risk of B-cell lymphoma in the univariate analysis, but not in the multivariate models. Compared with patients without cryoglobulins, patients with CV had a higher risk of death in both the univariate (HR = 11.68, 95% CI: 4.44, 30.74) and multivariate (HR = 4.36, 95% CI: 1.32, 14.47) models. CONCLUSION: Patients with primary SS who fulfilled criteria for cryoglobulinaemic vasculitis at diagnosis are at higher risk of death.

Protective role of mouse IgG1 in cryoglobulinaemia; insights from an animal model and relevance to human pathology.

Strait et al. described a novel mouse model of cryoglobulinaemia by challenging mice deficient in the immunoglobulin (Ig)G1 subclass (γ1(-) mice) with goat anti-mouse IgD [5]. The phenotype of wild-type mice was not remarkable, whereas γ1(-) mice developed IgG3 anti-goat IgG cryoglobulins as well as severe and lethal glomerulonephritis. Renal phenotype could not be rescued in γ1(-) mice by the deletion of C3, fragment crystalline γ receptor (FcγR) or J chain. On the other hand, early injection of IgG1, IgG2a or IgG2b inhibited the pathogenic effects of IgG3 in an antigen-dependent manner even in the absence of the FcγRIIb, an anti-inflammatory receptor. The authors concluded that the pathogenic role of IgG3 and the protective characteristic of IgG1 in this model were not explained by their abilities to bind to FcRs or effector molecules but are rather due to structural discrepancies enhancing the precipitation properties/solubility of IgG3/IgG1-containing immune complexes. The present article aims to discuss the current knowledge on IgG biology and the properties of IgGs explaining their differential propensity to acquire cryoglobulin activity.

Treatment of One Case with Cryoglobulinaemia Secondary to Connective Tissue Disease with Small Doses of Rituximab.

OBJECTIVE: This study aims to observe the clinical efficacy of low-dose rituximab in patients with cryoglobulinaemia secondary to connective tissue diseases. METHODS: Rituximab (100 mg) was infused in patients once a week for four weeks, combined with prednisone (20 mg) once a day, and reduced regularly. Treatment effect was observed regularly. RESULTS: Joint pain, fever, rash and fatigue symptoms in patients eased. The serology (globulin, erythrocyte sedimentation rate, C-reactive protein, lactate dehydrogenase and others) parameters returned to normal. CONCLUSION: Low-dose rituximab therapy for cryoglobulinaemia secondary to connective tissue diseases was safe and effective, and can be used as a treatment option in this condition.

Clinico-biological characteristics and treatment of type I monoclonal cryoglobulinaemia: a study of 64 cases.

This retrospective analysis was conducted in 64 patients diagnosed with type I cryoglobulinaemia (CG) followed at two French centres. Median follow-up was 6·75 years. CG was IgG in 60% and IgM in 40% of all cases and was asymptomatic in 16 patients (25%). Cold-triggered ischaemic skin manifestations were observed in 33 patients (51%). Neurological manifestations were observed in 15 patients and renal manifestations in 13. Most of the patients with necrotic purpura (14/16, P = 0·009) and renal manifestations (11/13, P = 0·057) had IgG CG. IgG CG was associated with monoclonal gammopathy of undetermined significance (MGUS), myeloma, chronic lymphocytic leukaemia and lymphoplasmocytic lymphoma in 18, 13, 5 and 2 patients, respectively. IgM CG was associated with MGUS and Waldenström macroglobulinaemia in 8 and 18 cases, respectively. One third of patients did not receive any specific treatment. Various treatments, including rituximab, were administered to 25/31 patients with IgG CG and 6/25 patients with IgM CG due to CG-related symptoms. Rituximab was ineffective in all cases associated with a predominantly plasmacytic proliferation. To conclude, type I CG has specific clinico-biological characteristics compared to type II CG. Furthermore, there are differences in terms of related manifestations between type I IgG and type I IgM CG.