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.

Collection and processing of hematopoietic progenitor cell products at risk of presenting with cold agglutination.

BACKGROUND AIMS: Cold agglutinins are commonly identified in transfusion laboratories and are defined by their ability to agglutinate erythrocytes at 3-4°C, with most demonstrating a titer >64. Similarly, cryoglobulins can precipitate from plasma when temperatures drop below central body temperature, resulting in erythrocyte agglutination. Thankfully, disease associated from these autoantibodies is rare, but unfortunately, such temperature ranges are routinely encountered outside of the body's circulation, as in an extracorporeal circuit during hematopoietic progenitor cell (HPC) collection or human cell therapy laboratory processing. When agglutination occurs ex vivo, complications with the collection and product may be encountered, resulting in adverse events or product loss. Here, we endeavor to share our experience in preventing and responding to known cases at risk of or spontaneous HPC agglutination in our human cell therapy laboratory. CASE REPORTS: Four cases of HPC products at risk for, or spontaneously, agglutinating were seen at our institution from 2018 to 2020. Planned modifications occurred, including ambient room temperature increases, tandem draw and return blood warmers, warm product transport and extended post-thaw warming occurred. In addition, unplanned modifications were undertaken, including warm HPC product processing and plasma replacement of the product when spontaneous agglutination of the product was identified. All recipients successfully engrafted after infusion. CONCLUSIONS: While uncommon, cold agglutination of HPC products can disrupt standard processes of collection and processing. Protocol modifications can circumvent adverse events for the donor and minimize product loss. Such process modifications should be considered in individuals with known risks for agglutination going to HPC donation/collection.

The characteristics of seronegative and seropositive non-hepatitis-associated cryoglobulinemic glomerulonephritis.

The clinicopathologic characteristics and long-term outcome of non-hepatitis-associated cryoglobulinemic glomerulonephritis (CryoGN) are not well-defined and cases with undetectable serum cryoglobulin (seronegative CryoGN) have not been investigated. To resolve this, we retrospectively identified 81 patients with biopsy-proven non-hepatitis CryoGN, including 22 with seronegative CryoGN. The median age was 61 years and 76% presented with nephritic syndrome. A hematologic condition was found in 89% of patients, including monoclonal gammopathy of renal significance (65%) and symptomatic lymphoproliferative disorder (35%). In the seropositive group, 56% had type II, 29% type I, and 8% type III cryoglobulin. Extrarenal manifestations, mostly of skin, were present in 64% and were significantly less common in seronegative CryoGN. Glomerular deposits by immunofluorescence were IgM dominant (84%) and polytypic (70%) in the seropositive group, whereas 52% of seronegative cases had monotypic deposits (i.e., type I cryoglobulin). Ultrastructurally, the deposits were organized in 77% of cases. Substructure appearance significantly differed according to the type of CryoGN, forming most commonly short cylindrical structures in type II and other organized substructures in type I CryoGN. Most patients were treated with clone-directed therapy. On follow up (median 33 months), 77% had partial or complete remission, 10% reached kidney failure and 14% died. Predictors of kidney failure on univariate analysis were AKIN stage 3, positive rheumatoid factor and biclonal gammopathy at diagnosis. We conclude that most CryoGN cases (types I and II) are due to a hematologic condition and are associated with favorable outcome after clone-directed therapy. Seronegative CryoGN accounts for about a quarter of cases and is mostly a kidney-limited disease. Thus, further investigations are needed to unravel the pathophysiology of seronegative CryoGN.

Practical Details for the Detection and Interpretation of Cryoglobulins.

BACKGROUND: Cryoglobulins are immunoglobulins that precipitate at low temperature. Strict preanalytical and analytical conditions are critical for the detection of cryoglobulins. CONTENT: This review will focus on practical recommendations for detection and characterization of cryoglobulins and the technical problems that may be encountered. A laboratory report format is proposed for presentation of these results that includes the parameters necessary for an optimal interpretation by clinicians. The first step of detection of cryoglobulins can be performed in any laboratory that has a 37 °C incubator and temperature-controlled centrifuge. The second step is the characterization of cryoglobulins, and this often must be performed in more specialized laboratories. Characterization includes immunoglobulin typing, for the classification of cryoglobulins and potential underlying disease(s); quantification of immunoglobulins and rheumatoid factor in the cryoprecipitate to define the pathogenicity; and quantification of serum complement, which is useful for diagnosis. SUMMARY: These practical recommendations will be useful for the accurate detection of cryoglobulins, an essential step for the diagnosis of cryoglobulinemic vasculitis, a rare but severe clinical manifestation of cryoglobulins.

Cryoglobulins and cold agglutinins for hand arm vibration syndrome.

BACKGROUND: Hand arm vibration syndrome (HAVS) is a condition caused by hand transmitted vibration from the use of hand-held vibrating tools or workpieces. The disease affects the vascular, neurological and musculoskeletal systems. The vascular component of HAVS is a form of secondary Raynaud's phenomenon. Other causes of disease must be excluded before attributing the cause to hand transmitted vibration. AIMS: To evaluate the prevalence, and utility of testing for, cryoglobulins and cold agglutinins in patients with HAVS symptoms. METHODS: A retrospective cohort study of 1183 patients referred for HAVS clinical assessment at St. Michael's Hospital, Toronto, Canada, between 2014 and 2020. The standard operating procedure at the clinic includes a detailed clinical and exposure history, physical examination, objective investigations and blood tests. Data were retrieved from patient chart review and laboratory investigation results for all cases with cryoglobulin and cold agglutinin testing. RESULTS: A total of 1183 patients had a serum cryoglobulin measurement. Eleven patients (1%) were positive. Seven positive results were 'low titre' (1% positive) and the other four results were 2%, 6%, 9% and 18%. The patient with a 9% positive cryoglobulin titre had previously diagnosed Sjögren's syndrome. There were no positive cold agglutinin tests in the 795 patients tested. CONCLUSIONS: Routine testing for cryoglobulins and cold agglutinins in patients with HAVS symptoms is not recommended because test positivity rates are negligible. Testing may be considered if the clinical history or routine blood investigations suggest evidence of underlying cryoglobulinaemia or cold agglutinin disease.

Rapidly progressive glomerulonephritis in a patient with angioimmunoblastic T-cell lymphoma: a rare autopsy case showing IgA vasculitis and cylinder-like deposits.

Angioimmunoblastic T-cell lymphoma (AITL), a hematological malignancy, originates from follicular helper T cells. The primary site of AITL is the lymph nodes, but extranodal presentation is frequent in patients with advanced stages. Here, we report a rare case of a patient with AITL presenting with rapidly progressive glomerulonephritis (RPGN). The patient underwent computed tomography, which showed systemic lymph node swelling. RPGN was noted at the time of admission. Livedo was observed in the lower limbs with purpura on the foot. The patient was diagnosed with AITL based on lymph node biopsy. Skin biopsy revealed vasculitis with immunoglobulin A (IgA) deposits. Renal biopsy revealed endocapillary proliferative glomerulonephritis with massive subendothelial deposits and intraluminal thrombi. Immunofluorescence showed IgA, IgG, and complement component 3c-predominant granular staining pattern in the capillary and mesangial areas. Electron micrographs demonstrated dense cylindrical-like deposits in the subendothelial space. Chemotherapy drugs were administered, but the patient's respiratory distress increased until death. Upon autopsy, membranoproliferative glomerulonephritis and extensive necrotizing cellular crescent formation were observed in the glomeruli. Taken together, this case is a rare combination of AITL and RPGN showing both cylinder-like deposits suggestive of cryoglobulinemic glomerulonephritis (CN) and IgA vasculitis.

Hypothermic circulatory arrest for aortic dissection with cryoglobulinemia.

Cryoglobulinemia is a cold-reactive autoimmune disease. A 64-year-old man with active cryoglobulinemia presented Stanford type A acute aortic dissection. He had been treated with immunosuppressive drugs and plasma exchange (PE) at our hospital; subsequently, qualitative analysis of cryoglobulin (CG) was negative. He underwent emergency ascending aorta replacement using cardiopulmonary bypass (CPB) under deep hypothermia circulatory arrest with selective cerebral perfusion. The total CPB time, aortic cross-clamp time, and selective cerebral perfusion time were 255, 153, 56 minutes, respectively, and the minimal nasopharyngeal temperature was 17.3°C. Our patient had no significant perioperative complications. Hence, if PE is performed appropriately and CG is negative, patients with cryoglobulinemia who exhibit severe preoperative symptoms can safely undergo surgery with deep hypothermia.

Efficacy of bortezomib in non-IgM type I cryoglobulinaemic vasculitis: a single-centre retrospective case series.

INTRODUCTION: Treatment of non-IgM type I cryoglobulinaemic vasculitis (CV) is challenging. Corticosteroids are first-line therapy, but relapses are frequent leading to therapeutic escalation. Bortezomib is a proteasome inhibitor with rapid effect on monoclonal component. However, its use in non-IgM type I CV has been barely reported. OBJECTIVE: To assess the efficacy of bortezomib in non-IgM type I CV. METHOD: Single-centre case series of four patients with non-IgM type I CV treated with bortezomib monotherapy. RESULTS: Two men and two women, 60-84 years old, received bortezomib monotherapy. Monoclonal component was IgG-λ (n = 2), IgA-λ and IgG-κ. Clinical features were necrotic rash (n = 3), synovitis (n = 3) and sensitive neuropathy (n = 2). CV was refractory to corticosteroids (n = 4), cyclophosphamide (n = 3) and rituximab (n = 2). Three patients experienced dramatic clinical improvement with undetectable cryoglobulin after three cycles (bortezomib 1.3 mg/m2 weekly). Each patient relapsed 4-18 months after treatment discontinuation. Bortezomib was unsuccessful after four cycles in one patient. Bortezomib toxicity included one pneumonia and 1 case of worsening neuropathic pain. CONCLUSION: Bortezomib in monotherapy should be considered as a valuable option in refractory non-IgM type I CV because of its swift efficacy and acceptable tolerance profile.

Cryoglobulinemic vasculitis with primary Sjögren's syndrome: A case report.

A 63-year-old Japanese woman with Sjögren's syndrome and peripheral neuropathy was admitted for evaluation of purpura on her lower extremities. Skin biopsy revealed leukocytoclastic vasculitis with the deposition of IgM, and serum cryoglobulin was positive. Accordingly, cryoglobulinemic vasculitis was diagnosed. There was no response to high-dose steroid therapy and plasmapheresis, but intravenous cyclophosphamide pulse therapy was effective for 4 years. Thereafter, proteinuria and hematuria developed, with cryoglobulinemic glomerulopathy being diagnosed by renal biopsy. Because the total dose of cyclophosphamide had reached 8000 mg, treatment with rituximab was selected. While rituximab was initially effective for her skin lesions and nephropathy, relapse occurred within 2 years and additional administration of this agent was required. The long-term efficacy of treatment for cryoglobulinemic vasculitis remains uncertain in patients with Sjögren's syndrome.

Mixed cryoglobulinaemia in a rhesus macaque (Macaca mulatta).

We report cryoglobulinaemia (CG) in a rhesus macaque whose serum sample was gel-like at <37°C and resolubilised upon warming. Mixed CG was diagnosed using serum protein electrophoresis and serum immunofixation electrophoresis. Renal damage and arthrophyma were observed during necropsy. This is the first report of CG in a non-human primate.

Fatal Cryocrystalglobulinemia With Intravascular and Renal Tubular Crystalline Deposits.

Cryocrystalglobulinemia is a rare variant of cryoglobulinemia in which monoclonal immunoglobulins self-assemble into crystalline arrays. We report a case of a 53-year-old man who presented with systemic thrombotic microangiopathy causing multiorgan failure, including decreased kidney, lung, and gastrointestinal function; skin necrosis; and mental status changes. Skin and kidney biopsy specimens showed intravascular thrombi, along with intravascular, intratubular, and periglomerular crystalline deposits. Typical morphologic features of cryoglobulinemia, such as a leukocytoclastic vasculitis and pseudothrombi, were absent. Spindled crystals precipitated in the cryoglobulin assay, and immunofixation showed them to be composed of monoclonal immunoglobulin G κ light chains. Ultrastructural analysis demonstrated deposits to have an array-like substructure. The patient was successfully treated with a combination of plasmapheresis, steroids, and bortezomib, but experienced a relapse and died 12 months after his initial diagnosis. Cryocrystalglobulinemia causes significant morbidity and mortality and should be classified as a monoclonal gammopathy of renal significance when it occurs in patients not meeting diagnostic criteria for multiple myeloma.

Type 1 Cryoglobulinemic Vasculitis Due to Monoclonal Gammopathy of Undetermined Significance Successfully Treated by Bortezomib Plus Dexamethasone.

Cryoglobulins are immunoglobulins that precipitate in cold conditions. Type I cryoglobulinemic vasculitis is associated with hematological malignancies. We herein report a case of steroid-resistant type 1 cryoglobulinemic vasculitis associated with monoclonal gammopathy of undetermined significance (MGUS) in a 47-year-old woman. By immunofixation of cryoglobulin, we found that the main component of cryoglobulin was the M protein due to MGUS, so treatment of MGUS was needed. Bortezomib+dexamethasone therapy resulted in a rapid decrease in cryoglobulin and improvement in the symptoms of cryoglobulinemic vasculitis. In refractory type I cryoglobulinemic vasculitis, treatment of the underlying gammaglobulinopathy should be considered.

Insights into the immunological description of cryoglobulins with regard to detection and characterization in Slovenian rheumatological patients.

The detection of cryoglobulins (CG) used to diagnose cryoglobulinemic vasculitis requires strict adherence to protocol, with emphasis on the preanalytical part. Our main objectives were to introduce a more sensitive and specific protocol for the detection of CG and to characterize CG in Slovenian patients diagnosed with cryoglobulinemic vasculitis, other vasculitides, connective tissue diseases or non-rheumatic diseases examined at the Department of Rheumatology (University Medical Centre Ljubljana). Samples were routinely analyzed for the presence of CG with the protocol using the Folin-Ciocalteu reagent. In the newly introduced protocol, the type of CG was determined by immunofixation on visually observed positive samples and the concentration of CG in the cryoprecipitate and rheumatoid factor (RF) activity were measured by nephelometry. RF, C3c and C4 were measured in patients` serum and a decision tree analysis was performed using all results. The agreement between negative and positive results between the two protocols was 86%. Of the 258 patient samples tested, we found 56 patients (21.7%) with positive CG (37.5% - type II, 62.5% - type III). The RF activity was observed in 21.4% of CG positive subjects. The median concentration of type II CG was significantly higher than that of type III CG (67.4 mg/L vs. 45.0 mg/L, p = 0.037). Patients with type II had lower C4 concentrations and higher RF compared to patients with type III CG. In the decision tree, C4 was the strongest predictor of cryoglobulinemia in patients. With the newly implemented protocol, we were able to improve the detection and quantification of CG in the samples of our rheumatology patients and report the results to adequately support clinicians.

A Case of Mesangial Proliferative Nephritis Caused by Slow Cryoglobulin.

The patient was a woman in her 60s. She was found to have proteinuria on a health checkup. She did not have any particular subjective symptoms, and no definitive diagnosis was made, despite serological findings indicative of immune abnormalities. A renal biopsy was performed. Light microscopy of renal tissue section revealed mesangial proliferative nephritis. Electron microscopic findings included electron-dense deposits and fibrillar/tubular structures with a diameter of 20-30 nm. These findings suggested the presence of cryoglobulin (CG), but CG was not detected in qualitative or quantitative hematologic tests. Thus, the serum samples were stored at 37°C for a long period of time and then cooled to 4°C. When the obtained precipitates were examined, CG was successfully detected. CG that precipitates only after a long period of time is referred to as slow cryoglobulin (sCG), and sCG is extremely rare. The present case is the first documented case, to our knowledge, of renal disorders caused by sCG. It should be noted that there are some cases in which it takes much time for CG to precipitate. Thus, when CG cannot be detected, it is necessary to spend much time to determine whether CG precipitates.

Serum protein electrophoresis and rheumatoid factor analysis is an effective screening strategy for cryoglobulinaemia.

Accurate serum cryoglobulin detection is important to allow prompt treatment but laboratory testing requires stringent pre-analytical conditions and has long turnaround times. Serum protein electrophoresis (EPG) for paraproteinaemia and rheumatoid factor (RF) analysis may offer an effective initial screening strategy for the presence of cryoglobulinaemia. We retrospectively assessed the sensitivity of ancillary EPG and RF testing for the presence of serum cryoglobulinaemia in 586 eligible cryoglobulin positive samples received at the Royal Prince Alfred and Liverpool Hospital immunopathology laboratories over an 11-year period. Ninety-one percent of all cryoglobulin positive samples had either a detectable paraprotein or RF activity, with greatest sensitivity for type I and type II cryoglobulins (97% and 98%, respectively). The sensitivity remained high irrespective of whether EPG and RF analysis was performed with the same, or different, pre-analytical collection conditions to the cryoglobulin collection (92% vs 90%, p=0.46). Only two patients with detected cryoglobulins and no associated paraprotein or RF activity had clinical features of cryoglobulinaemia and neither required treatment. This study demonstrates that serum EPG and RF analysis has high sensitivity for the detection of clinically relevant cryoglobulinaemia, even when not collected under ideal pre-analytical conditions, and potentially offers a prompt and effective screening strategy.

Cryoglobulinemic Vasculitis Associated with Monoclonal Gammopathy of Undetermined Significance Developed after Sustained Virologic Response of Hepatitis C.

A 72-year-old woman had a history of chronic hepatitis C virus (HCV) infection previously treated with interferon to achieve a sustained virologic response. Thereafter, she developed polyarthritis and purpura of the lower extremities as well as progressive renal dysfunction with hypertension and proteinuria that had occurred in the last three months. Laboratory investigations revealed seropositivity for cryoglobulin but negative findings for HCV RNA. She was ultimately diagnosed with cryoglobulinemic glomerulonephritis complicated by monoclonal gammopathy of undetermined significance (MGUS) based on the pathological findings of the kidney and bone marrow, indicating that MGUS-induced cryoglobulinemic vasculitis may occur even after HCV elimination.

The wide spectrum of cryoglobulinemic vasculitis and an overview of therapeutic advancements.

Immunoglobulins that reversibly precipitate at temperatures below 37 °C are called cryoglobulins (CGs). Cryoglobulinemia often manifests as cryoglobulinemic vasculitis (CV), whose symptoms range in severity from purpuric eruptions to life-threatening features. The majority of CV patients are infected with hepatitis C virus (HCV), whereas lymphoproliferative disorders or connective tissue diseases (CTD) are commonly diagnosed among patients with CV of non-infectious origin. In the absence of detectable associated disease, cryoglobulinemia is classified as "essential" (EMC). All HCV-positive CV patients should be given direct-acting antiviral agents (DAAs) that are consistently able to induce a sustained virologic response (SVR). Glucocorticoids (GCs) can mitigate CV-associated vasculitis, but they have no role as maintenance therapy. Cyclophosphamide restrains the hyperactive phase(s) of the disease and the post-apheresis rebound of newly synthesized CGs. Its use has been largely replaced by rituximab (RTX) in patients unresponsive to DAAs, patients progressing to B-cell non-Hodgkin lymphoma (B-NHL) and patients in whom CV persists or reappears after clearance of HCV. Therapeutic apheresis is an emergency treatment for CV patients with hyperviscosity syndrome. HCV-positive CV patients are at an increased risk of developing NHL, but the achievement of SVR can effectively prevent HCV-related NHL or induce the remission of an already established lymphoma, even without chemotherapy. The treatment of patients with IgM or IgG monoclonal cryoglobulins and an underlying immunoproliferative disorder is based on the regimens adopted for patients with the same B-cell malignancies but without circulating CGs. For patients with CTD, GCs plus alkylating agents or RTX are similarly effective as first-line therapy and in the relapse/refractory setting. In patients with EMC, treatment should consist of GCs plus RTX, with the dose of GCs tapered as soon as possible to reduce the risk of infectious complications.