Cryoglobulinemic Vasculitis in Disguise: Cryofibrinogenemia as Variant of Monoclonal Gammopathy of Renal Significance

Monoclonal gammopathy with cryoactivity (ie, cryoglobulins) that causes glomerulonephritis is considered within the spectrum of monoclonal gammopathy of renal significance. Cryofibrinogenemia (cryoactivity of coagulation factors) is very rarely associated with glomerulonephritis. We present a 39-year-old woman with a relapsing nephrotic syndrome. Laboratory investigation detected cryofibrinogen; the precipitate consisted of fibrinogen and a monoclonal immunoglobulin (M-protein; IgG-λ), and the latter was also detected in serum (4g/L). Initial conventional immunosuppressive therapy resulted in temporary renal remission. In view of the M-protein, subsequent therapy consisted of bortezomib/dexamethasone and high-dose melphalan followed by autologous hematopoietic stem cell transplantation, and resulted in a very good partial hematological response and temporary renal remission. However, after hematological and renal relapse, we performed unique experiments to clarify the role of the M-protein. Mixing patient serum with donor plasma resulted in cryoactivity, composed of M-protein+fibrinogen. Patient plasma deprived of M-protein did not have cryoactivity. Therefore, cryoactivity was dependent on the M-protein. We started lenalidomide, which resulted in very good partial hematological and renal remission. Thus, cryofibrinogenemia can be the consequence of an M-protein, which we suggest should be defined as monoclonal gammopathy of renal significance.

IgM monoclonal gammopathy of undetermined significance: clinicopathologic features with and without IgM-related disorders

A subset of patients with immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) develop IgM-related disorders (IgM-RD) including peripheral neuropathy, cryoglobulinemia and/or cold agglutinin disease (CAD). We examined the clinical and bone marrow pathologic findings in 191 IgM MGUS patients (2016 World Health Oragnization criteria). Clonal plasma cells were identified in 41 of 171 (24%) cases by immunohistochemistry (IHC) and clonal B cells in 43 of 157 (27%). IgM-RD was identified in 82 (43%) cases, including peripheral neuropathy (n=67, 35%), cryoglobulinemia (n=21, 11%), and CAD (n=10, 5%). Cases of CAD showed distinctive features including lack of MYD88 mutations (P=0.048), supporting the concept of primary CAD as a distinct clinicopathologic disorder. Following exclusion of CAD, comparison of the remaining cases with (n=72) or without (n=109) IgM-RD showed IgM-RD to be more frequent in men than women (P=0.02) and to be more highly associated with MYD88 L265P (P=0.011). Cases with and without IgM-RD otherwise showed similar features including serum IgM concentrations, presence of lymphoid aggregates, clonal B cells by flow cytometry or clonal plasma cells by IHC. No differences were observed in overall survival between cases with and without IgM-RD. No cases in this series met criteria for plasma cell type IgM MGUS as defined in the 2022 International Consensus Classification of lymphoid neoplasms. These results show IgM-RD to be common in patients with IgM MGUS. While CAD shows distinctive features, the remaining cases of IgM-RD largely show pathologic findings similar to IgM MGUS without IgM-RD.

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.

Isolated anti-Ro52 identifies a severe subset of Sjögren’s syndrome patients

Introduction

Serum autoantibodies targeting the SSA/Ro proteins are a key component of the classification criteria for the diagnosis of Sjögren’s syndrome (SS). Most patients' serum reacts with both Ro60 and Ro52 proteins. Here we compare the molecular and clinical characteristics of patients diagnosed with SS with anti-Ro52 in the presence or absence of anti-Ro60/La autoantibodies.

Methods

A cross-sectional study was performed. Patients in the SS biobank at Westmead Hospital (Sydney, Australia) that were positive for anti-Ro52 were included and stratified based on the absence (isolated) or presence (combined) of anti-Ro60/La, measured by line immunoassay. We examined clinical associations and the serological and molecular characteristics of anti-Ro52 using ELISA and mass spectrometry in serological groups.

Results

A total of 123 SS patients were included for study. SS patients with isolated anti-Ro52 (12%) identified a severe serological subset characterised by higher disease activity, vasculitis, pulmonary involvement, rheumatoid factor (RhF) and cryoglobulinaemia. Serum antibodies reacting with Ro52 in the isolated anti-Ro52 subset displayed less isotype switching, less immunoglobulin variable region subfamily usage and a lower degree of somatic hypermutation than the combined anti-Ro52 subset.

Conclusions

In our cohort of SS patients, isolated anti-Ro52 represents a severe subset of SS, and is associated with the presence of cryoglobulinaemia. We therefore provide clinical relevance to the stratification of SS patients by their sero-reactivities. It is possible that the autoantibody patterns may be immunological epiphenomena of the underlying disease process, and further work is required to unearth the mechanisms of the differential clinical phenotypes.

Human hepatitis viruses-associated cutaneous and systemic vasculitis

Human hepatitis viruses (HHVs) include hepatitis A virus, hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus, and hepatitis E virus and can cause liver inflammation in their common human host. Usually, HHV is rapidly cleared by the immune system, following acute HHV invasion. The morbidities associated with hepatitis A virus and hepatitis E virus infection occur shortly after their intrusion, in the acute stage. Nevertheless, the viral infectious process can persist for a long period of time, especially in HBV and HCV infection, leading to chronic hepatitis and further progressing to hepatic cirrhosis and liver cancer. HHV infection brings about complications in other organs, and both acute and chronic hepatitis have been associated with clinical presentations outside the liver. Vascular involvement with cutaneous and systemic vasculitis is a well-known extrahepatic presentation; moreover, there is growing evidence for a possible causal relationship between viral pathogens and vasculitis. Except for hepatitis delta virus, other HHVs have participated in the etiopathogenesis of cutaneous and systemic vasculitis via different mechanisms, including direct viral invasion of vascular endothelial cells, immune complex-mediated vessel wall damage, and autoimmune responses with stimulation of autoreactive B-cells and impaired regulatory T-cells. Cryoglobulinemic vasculitis and polyarteritis nodosa are recognized for their association with chronic HHV infection. Although therapeutic guidelines for HHV-associated vasculitis have not yet been established, antiviral therapy should be initiated in HBV and HCV-related systemic vasculitis in addition to the use of corticosteroids. Plasma exchange and/or combined cyclophosphamide and corticosteroid therapy can be considered in patients with severe life-threatening vasculitis manifestations.

[CRYOGLOBULINEMIA AND ENDOCARDITIS AS A PRESENTATION OF COXIELLA BURNETII (Q-FEVER) INFECTION]

An infection with Coxiella burnetii (Q FEVER) can be manifested as an autoimmune or rheumatologic disease as it was presented in our patient, showing cryoglobulinemia and massive destruction of the aortic valve. In the differential diagnosis we must consider an infection with Coxiella burnatii which may change the course of the disease and may cause life-threatening manifestations.

Hepatitis C virus-induced glomerular disease and posterior reversible encephalopathy syndrome after liver transplant: Case report and literature review

Chronic hepatitis C virus (HCV) infection is associated with numerous extra-hepatic complications, including neurological and renal manifestations. We describe the case of a 67-year-old Caucasian man with HCV-associated cryoglobulinemic glomerulonephritis, cirrhosis, and hepatocellular carcinoma. The early posttransplant course was complicated by fibrosing cholestatic hepatitis due to recurrent HCV in the graft (HCV RNA up to 44,944,438 IU/mL). Proliferative glomerulonephritis (nephritic and nephrotic syndrome) with mixed cryoglobulinemia (purpura) was also recorded. Seventy-two days after surgery, the patient presented with seizures and arterial hypertension; brain magnetic resonance imaging indicated the diagnosis of posterior reversible encephalopathy syndrome (PRES). PRES responded well to medical treatment with complete resolution of neurological changes. Antiviral therapy (sofosbuvir and ribavirin, six months) gave a sustained viral response with the improvement of cryoglobulinemic symptoms (including glomerular disease). Repeat liver biopsy revealed the regression of cholestatic damage and perisinusoidal fibrosis. The current follow-up shows stable chronic renal failure (serum creatinine: 1.4 mg/dL) and mild nephritic syndrome. The impact of extrahepatic manifestations of HCV on patient outcomes is highlighted from novel observational studies reporting a relationship between HCV cure (as expressed by the sustained viral response) and a decrease in both liver-related and renal complications. Clinical trials evaluating the efficacy and tolerance of novel direct-acting antiviral agents for the management of HCV-associated glomerular diseases are underway.

[Osteonecrosis developing after rituximab-containing chemotherapy for Waldenström macroglobulinemia]

A 71-year-old woman presented with fever, weight loss, and anemia because of recurrent Waldenström macroglobulinemia (WM) with cryoglobulinemia. Treatment with five cycles of doxorubicin, vincristine, cyclophosphamide, and prednisolone (CHOP) therapy was initiated, which resulted in insufficient improvement in anemia. Hence, a combination of rituximab and CHOP therapy was subsequently initiated. The patient complained of lumbago and lower leg pain on day 4 of the chemoimmunotherapy. X-ray findings for the affected sites were unremarkable, and the patient's symptoms gradually and spontaneously subsided. Rituximab monotherapy was then administered, which resulted in the deterioration of her symptoms. Magnetic resonance imaging revealed osteonecrosis of the bilateral distal ends of the femur, and proximal and distal ends of the tibia. This is the first case of lower leg osteonecrosis complicating chemoimmunotherapy for WM. Osteonecrosis may be an unusual adverse effect of rituximab therapy for WM. Tumor lysis by rituximab may have contributed to the pathogenesis of this complication. MRI assessment should be considered when WM patients complain of bone pain following rituximab-containing chemotherapy.

Serum Biomarkers for Discrimination between Hepatitis C-Related Arthropathy and Early Rheumatoid Arthritis

In the present study, we aimed to estimate the concentrations of cytokines (interleukin 6, IL-6, tumor necrosis factor-α, TNF-α) and auto-antibodies (rheumatoid factor IgM isotype, IgM-RF, antinuclear auto-antibodies, ANA, anti–cyclic citrullinated peptide antibodies IgG isotype, IgG anti-CCP3.1, anti-cardiolipin IgG isotype, IgG anti-aCL) in serum of patients with eRA (early rheumatoid arthritis) and HCVrA (hepatitis C virus-related arthropathy) and to assess the utility of IL-6, TNF-α together with IgG anti-CCP and IgM-RF in distinguishing between patients with true eRA and HCVrA, in the idea of using them as differential immunomarkers. Serum samples were collected from 54 patients (30 diagnosed with eRA-subgroup 1 and 24 with HCVrA-subgroup 2) and from 28 healthy control persons. For the evaluation of serum concentrations of studied cytokines and auto-antibodies, we used immunoenzimatique techniques. The serum concentrations of both proinflammatory cytokines were statistically significantly higher in patients of subgroup 1 and subgroup 2, compared to the control group (p < 0.0001). Our study showed statistically significant differences of the mean concentrations only for ANA and IgG anti-CCP between subgroup 1 and subgroup 2. We also observed that IL-6 and TNF-α better correlated with auto-antibodies in subgroup 1 than in subgroup 2. In both subgroups of patients, ROC curves indicated that IL-6 and TNF-α have a higher diagnostic utility as markers of disease. In conclusion, we can say that, due to high sensitivity for diagnostic accuracy, determination of serum concentrations of IL-6 and TNF-α, possibly in combination with auto-antibodies, could be useful in the diagnosis and distinguishing between patients with true eRA and HCV patients with articular manifestation and may prove useful in the monitoring of the disease course.

Systemic vasculitides: a critical digest of the most recent literature

Herewith we provide our annual digest of the recent literature on systemic vasculitides. In this manuscript, we reviewed all the articles published during the last 12 months on large-, medium- and small-vessel vasculitis and selected the most relevant studies regarding the epidemiology, pathogenesis and management of systemic vasculitis. In particular, we focused the attention on giant cell arteritis, ANCA-associated vasculitis and cryoglobulinaemia.

Immunological profiles determine neurological involvement in Sjögren's syndrome

BACKGROUND

Up to 68% of patients with primary Sjögren's syndrome (pSS) undergo neurological complications, and evidence for distinct immunological subgroups is emerging. We sought to determine systemic and immunological profiles associated with neurological manifestations.

METHODS

420 patients fulfilling the 2002 American-European pSS criteria were retrospectively analyzed. Neurological manifestations were diagnosed through clinical, biological, electrophysiological, and imaging findings. Biographical, clinical, and laboratory data were compared.

RESULTS

Within 93 (22%) patients with neurological manifestations, peripheral and central nervous systems were involved in 66% and 44%, respectively. Raynaud's phenomenon, cutaneous vasculitis, renal involvement, and cryoglobulinemia were associated with sensorimotor neuropathy and mononeuritis multiplex (p<0.05). Conversely, pure sensory neuropathy occurred without extraglandular manifestation, and without anti-Ro/SSA antibodies (p<0.05). All neurological manifestations were associated with increased use of corticosteroids and immunosuppressive drugs (p<0.05).

CONCLUSIONS

In pSS, patients with sensorimotor neuropathies and pure sensory neuropathies have distinct extraglandular and immunological profiles.

Extreme hypercomplementemia in the setting of mixed cryoglobulinemia

Elevated levels of complement components, C3 and C4, are often seen in inflammatory diseases. They are generally not thought to be responsible for organ injury but simply reflect stimulation of the immune system. Extremely high elevations of these components are rarely seen. Such values are usually reported in patients with hematopoietic malignancies. We report here a case of C3 elevation to 9.22 g/L (5 times the upper limit of normal) and C4 elevation to 2.48 g/L (6 times the upper limit of normal). To our knowledge, no prior elevations of this magnitude have been reported previously from our institution or in the published medical literature (+/- MEDLINE search, using keywords hypercomplementemia, C3, C4, and lymphoplasmacytic lymphoma). In this case, there appeared to be no adverse end-organ damage from the excessive complement components or their activation.

[Case of fulminant mixed cryoglobulinemia developing after atrial myxoma resection]

A 63-year-old man, with a 13-year history of asymptomatic proteinuria, was diagnosed with left atrial myxoma at the onset of heart failure. After resection of the tumor by hypothermal surgery, the patient developed fever, renal failure and skin rash. The diagnosis was type II mixed cryoglobulinemia accompanied by an IgMlambda clone with high titers of rheumatoid factor activity and polyclonal IgG. Treatment with high doses of steroids and plasmapheresis was ineffective, and the patient died of colon necrosis due to thrombotic occlusion in the supra-mesenteric arteries. Although the patient had suffered from sporadic Raynaud's phenomenon and purpura of the lower extremities from the age of 60 years, cryoglobulinemia was not suspected before surgery because of the atrial myxoma. Thus, we suggest that it is important to perform laboratory tests for cryoproteins before hypothermal surgery.

Motor-axonal polyneuropathy associated with hepatitis C virus

The association between hepatitis C virus (HCV) infection, the presence of mixed cryoglobulinemia and peripheral neuropathy is well-documented (Apartis et al., 1996). HCV is the chief cause of essential mixed cryoglobulinemia (type II cryoglobulinemia) with cryoglobulins present in up to half of patients with HCV infection (Akriviadis et al., 1997). More recently it has been stated that peripheral polyneuropathy may be associated with HCV chronic infection without mixed cryoglobulinemia (Lidove et al., 2001). Patients usually present with a clinical and electrophysiology--predominantly sensory axonopathies (Apartis et al., 1996; Heckmann et al., 1999) or less frequently with fulminating vasculitis and mononeuropathy multiplex syndrome (David et al., 1996)--especially when associated with cryoglobulinemia. We report, for the first time, the association between pure motor-axonal polyneuropathy and HCV infection without cryoglobulinemia.

Severe Raynaud's phenomenon with chronic hepatis C disease treated with interferon

Severe Raynaud's phenomenon developed in a 5-year-old girl with chronic hepatitis C infection at the fifth month of interferon therapy in the absence of cryoglobulinemia and other conditions commonly associated with secondary Raynaud's phenomenon. Although interferon therapy was promptly discontinued, Raynaud's phenomenon persisted for 4 months with appearance of necrotic-ulcerous lesions at the tips of fingers.

Type-I cryoglobulinemia-like histopathologic changes in tick bites: a useful clue for tissue diagnosis in the absence of tick parts

BACKGROUND

The histopathologic findings of localized reactions to tick bites may present as diagnostic dilemmas, especially if there is no history of a tick bite, or if the tick's mouthparts are not present in the biopsied skin.

OBJECTIVE

Skin biopsies of patients with a clinical history of a tick bite were selected and reviewed with the aim of detecting a common histopathologic denominator which could serve as a useful clue to the diagnosis, especially when the tick's mouthparts are absent.

METHODS

Hematoxylin and eosin-stained slides of 15 skin biopsies of tick bites were retrieved from three dermatopathology and pathology laboratories. Where additional paraffin-embedded tissue was available, additional sections were also stained with periodic acid-Schiff (PAS) and phosphotungstic acid-hematoxylin (PTAH).

RESULTS

In every case in which adequate tissue was available (13/ 15 biopsies), the capillaries and postcapillary venules of the superficial and deep vascular plexi adjacent to the attachment's site were filled with thrombi. Fibrin thrombi were seen in association with other more numerous thrombi characterized by homogeneous eosinophilic hyaline material similar to the cryoprecipitate present in type I (monoclonal) cryoglobulinemia. All thrombi were positive for PAS and PTAH; however, the latter staining was minimally present in the hyaline thrombi. In most cases, the site of the tick bite showed ulceration, with an underlying wedge-shaped superficial and deep perivascular and occasionally interstitial mixed lymphohistiocytic infiltrate. In addition, there were eosinophils, numerous neutrophils and extravasated erythrocytes. Other findings included suppurative necrosis (7/15) cases, giant-cell reaction (one case), fat necrosis (one case) and eccrine gland necrosis (one case).

CONCLUSIONS

Vascular eosinophilic hyaline thrombi were found to be a frequent histologic manifestation of a tick bite. This finding may be related to the secretory products of the tick's saliva during inoculation. We believe that a tick bite should be suspected when focal intravascular hyaline occlusion is observed, and that it should be included in the differential diagnosis of type I (monoclonal) cryoglobulinemia, even if there is no history of a tick bite or if tick parts are not present in the skin biopsy specimen.

Ultrastructural 'fingerprint' in cryoprecipitates and glomerular deposits: a clinicopathologic analysis of fingerprint deposits

Organized glomerular electron-dense deposits with a fingerprint pattern are well known in some patients of lupus nephritis or cryoglobulinemia. In general, these two diseases are always discussed separately as the causes of such deposits. However, 3 of our 5 lupus patients with glomerular fingerprint deposits also had cryoglobulinemia. One of the remaining 2 patients died and the other was lost to follow-up. The purpose of our study was to seek an appropriate clinicopathologic assessment of fingerprint deposits. All these patients showed overt proteinuria, active urinary sediment, a high degree of activity of lupus nephritis, and diffuse proliferative glomerulonephritis (WHO class IV). Their cryoprecipitates and renal biopsy specimens were investigated by means of immunochemistry, immunofluorescence and electron microscopy. The ultrastructural 'fingerprint' structures were exactly the same in the cryoprecipitates and in the glomerular deposits in 2 of 3 lupus patients with cryoglobulinemia, as were IgG, IgM and IgA. Therefore, these observations furnish emerging morphologic evidence for the glomerular deposition of immune complexes of circulating cryoglobulins in lupus nephritis. In addition, electron microscopic fingerprint deposits on renal biopsy or cryoprecipitate can be regarded as a very sensible marker of concomitant or subsequent development of diffuse lupus nephritis. If the patient is accompanied by nephritic syndrome, an early trial of immunosuppressive therapy may be warranted.

The incidence of cryoglobulinaemia as determined by a turbidimetric method

The incidence of cryoglobulinaemia was determined in 34 normal persons and in 56 sera from 52 patients with miscellaneous disorders. The turbidity of a sample of serum after 18 hours' refrigeration at 4 degrees C. was compared with a sample of the same serum incubated at 38 degrees C. for the same period of time. All refrigerated sera showed a greater turbidity than incubated sera. The abnormal sera showed a high degree of statistically significant correlation between total protein, gamma globulin, and the amount of cryoglobulinaemia. There was no significant correlation between cryoglobulinaemia and the age and sex of individuals or any of the other protein fractions. The results suggest that some degree of cryoglobulinaemia is of almost universal occurrence in various unrelated disorders and that this tendency to precipitate out in the cold is a characteristic of the gamma globulin group of proteins, especially when present in excess.

Characterization of overt B-cell lymphomas in patients with hepatitis C virus infection

A pathogenetic role of the hepatitis C virus (HCV) has been hypothesized for a subset of B-cell non-Hodgkin's lymphomas (NHLs). However, the preliminary characterization of B-cell NHLs in HCV-infected individuals has been poorly addressed. In the present study, we report detailed information on 35 consecutive patients with overt B-cell NHL of recent onset and HCV infection; all patients referred to a single oncological center in Northeast Italy. Histopathologic evaluation was performed by a single reference hemopathologist, and the link with the two relevant autoimmune diseases predisposing to B-cell NHL and in which HCV has been implied, ie, "essential" mixed cryoglobulinemia (EMC) and Sjogren's syndrome, was investigated. Control groups included 122 consecutive HCV-negative patients with B-cell NHL and 464 consecutive histopathologic cases of B-cell NHL referred to the same center, as well as 127 consecutive patients with HCV infection and without lymphoma referred to a different center in the same geographical area. B-cell NHLs in HCV-infected patients frequently presented at onset (1) an extranodal localization with peculiar target organs of HCV infection (ie, the liver and major salivary glands) being significantly overrepresented; (2) a diffuse large cell histotype without any prior history of low-grade B-cell malignancy or bone marrow involvement; and (3) a weak association with a full-blown predisposing autoimmune disease, although serum autoimmune features were common and cryoglobulins were always present. Therefore, the HCV-related B-cell NHLs in this oncological series presented distinctive features compared with B-cell NHLs in HCV-negative patients, and they differed from bone marrow low-grade NHLs frequently diagnosed in HCV-positive patients with EMC. Such novel information may be relevant for future research aimed at clarifying the possible link between HCV infection, autoimmunity, nonmalignant B-cell lymphoproliferation, and overt B-cell malignancy.

Hepatitis C virus infection and monoclonal gammopathies not associated with cryoglobulinemia

A pathogenetic role of HCV has been recently postulated in some lymphoproliferative disorders and in particular in essential mixed cryoglobulinemia. To assess the relevance of HCV infection in multiple myeloma, Waldenström's macroglobulinemia and monoclonal gammopathy of undetermined significance in the absence of cryoglobulinemia (cryo-ve MG), 102 patients were evaluated for antiHCV, HCVRNA and HCV genotypes. A control group of 466 patients referring for acute trauma to the Orthopedic Division of our hospital was also studied. The overall prevalence of HCV was 15.6% in MG patients and 5.4% in the control group (P= < 0.001). Since only patients with MG older than 50 years had HCV infection, we compared the prevalence rate of infection in patients aged 50 and older: in cryo-ve MG HCV prevalence was 17.9%, while in patients with an acute trauma it was 10%; the difference was not statistically significant. In addition, occurrence of cryo-ve MG was investigated in 614 antiHCV+ patients with chronic liver disease and was found in 1.9%. Comparing all the 28 cryo-ve MG patients HCV+ with an appropriately matched control group of HCV+ patients without MG, no difference in severity of liver disease and genotype distribution was detected. These findings show that: (1) among cryo-ve MG, HCV infection is frequent as shown in the appropriately matched control population; (2) prevalence of cryo-ve MG in antiHCV patients with chronic liver disease is similar to the rate found in the general population; and (3) HCV infection and disease do not differ in patients with and without cryo-ve MG.

[Cryoglobulinemia]

Cryoglobulins are proteins that precipitate when cooled and dissolve when heated. Cryoglobulinemia may be classified into Type I (monoclonal), Type II (mixed), and Type III (polyclonal). About 5 to 10% of myeloma proteins and 7 to 20% of primary macroglobulinemia proteins are cryoprecipitable (Type I cryoglobulin), and more than half of these have no symptoms attributable to cryoglobulin nature of their M-component. The most common symptoms of Type I cryoglobulinemia include Raynaud's phenomenon, necrosis of the toes or legs, vascular purpura, and urticaria. In Type I cryoglobulinemia due to plasma cell dyscrasias, treatment is directed primarily at the underlying disease. Plasmapheresis and cryofiltration may be helpful particularly when this can be combined with effective chemotherapy.

Cryoglobulinemia and other dysproteinemias, familial Mediterranean fever, and POEMS syndrome

The introduction of newer technology in the past few years, especially the use of second-generation enzyme-linked immunosorbent assays, recombinant immunoblot assays, reverse transcriptase, and DNA amplification, have clearly defined the role of hepatitis C virus as the most important etiologic factor in the development of mixed cryoglobulinemia. This has led to a better understanding of the pathogenic mechanisms involved in disease expression, particularly vasculitis, and also has provided a rationale for the use of interferon alfa and other antiviral drugs in the therapy of these disorders. The clinical manifestations of the syndrome also have been well characterized, as well as some of the risk factors. There also has been an improvement in our understanding of the pathogenic mechanisms involved in multiple myeloma and related monoclonal gammopathies, as well as several attempts to improve early recognition of bone disease with magnetic resonance imaging. The susceptibility gene for familial Mediterranean fever has been better characterized, as have risk factors for colchicine toxicity. The role of cytokines has been better delineated for both monoclonal gammopathies and POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome.

Cryoimmunoglobulinaemia in patients with renal disease. II attempts to demonstrate-that cryoprecipitate contain autoantibodies and/or antigen

Seventeen patients found to have cryoimmunoglobulinaemia (CIG) while undergoing diagnostic renal biopsy and two patients with CIG without renal disease were studied. The cryoprecipitates (CP) from four of seven patients tested contained enhanced concentrations of autoantibodies: to vascular smooth muscle, autologous skeletal muscle, nuclear antigen and cardiac muscle. Antisera were made in rabbits against each of the 19 CP; six antisera contained antibodies to sarcolemma of skeletal muscle, nuclear antigen, elastin, reticulin, renal eluate and autologous kidney immune deposits respectively. Although one anti-CP antiserum bound to renal deposits, eight others tested on autologous renal biopsies did not. The data suggest that CP frequently may contain enhanced concentration of circulating autoantibodies and/or tissue antigens, possibly as immune complexes. In only one case was it possible to demonstrate that there was a common immunological identity between CP and renal Ig deposits.

DISORDERS OF BLOOD. IV. CRYOGLOBULINEMIA: A PRELIMINARY REPORT

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