The cryoglobulinaemias

Mixed cryoglobulinemia decelerates hepatocellular carcinoma development in hepatitis C patients with SVR by downregulating regulatory B cells: a 12-year prospective cohort study

How mixed cryoglobulinemia (MC) affects cancer risk in chronic hepatitis C patients with sustained virologic response (SVR) remains unclear. In a 12-year prospective study, post-SVR MC was assessed every 3‒6 months. Among the 891 SVR patients, 265 (29.7%) had baseline (24 weeks after completing anti-HCV therapy) MC, and the 12-year cancer cumulative incidence was 19.7%. Among the 73 patients who developed cancer, 37 (50.7%) had hepatocellular carcinoma (HCC), with the following associated baseline variables: for cancer, male sex, age and alanine aminotransferase (ALT) levels; for HCC, male sex, age, and cirrhosis; and for non-HCC cancer, rheumatoid factor levels. Among patients with post-SVR HCC, the mean time to HCC was longer in those with than in those without baseline MC (1545.4 ± 276.5 vs. 856.9 ± 115.2 days, p = 0.014). Patients with baseline MC had decreased circulating interleukin-10 (IL-10)-positive B cell (CD19+IL-10+cells/CD19+cells) (31.24 ± 16.14 vs. 40.08 ± 15.42%, p = 0.031), regulatory B cell (Breg) (CD19+CD24hi CD27+cells/CD19+cells) (10.45 ± 7.10 vs. 15.76 ± 9.14%, p = 0.035), IL-10-positive Breg (CD19+CD24hiCD27+IL-10+cells/CD19+cells) (5.06 ± 4.68 vs. 8.83 ± 5.46%, p = 0.015) and HCC-infiltrating Breg (18.6 ± 10 vs. 33.51 ± 6.8%, p = 0.022) ratios but comparable circulating and HCC-infiltrating regulatory T cell ratios relative to patients without baseline MC. In conclusion, old male SVR patients with elevated ALT levels or cirrhosis require intensive monitoring for cancer development, especially HCC. Tailored HCC follow-up is needed for SVR patients according to their baseline MC, which might downregulate Bregs to decelerate HCC development for almost 2 years.

Early detection of unusual cryoglobulinemia from automated cell counts and blood films

Cryoglobulins are circulating immunoglobulins characterized by reversible cold-induced precipitation. The process of serum cryoprecipitation, performed at 4 °C, takes three to seven days, which leads to delays in obtaining cryoglobulinemia lab-results. Here, we report two cases of cryoglobulinemia, each with distinct cryoglobulin-induced features that were identifiable through automated hemocytometry and blood smear analysis. The blood smear showed neutrophilic inclusions and amorphous extra-cellular material, and the automated hematology analyzer displayed abnormal scatterplots. All these unique features positively correlated with the duration the blood sample was kept at room temperature prior to analysis. These hemocytometric abnormalities may serve as early indicators for the diagnosis of cryoglobulinemia, potentially aiding the detection of this condition.

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

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

[Vasculitic involvement of the skeletal muscle and the peripheral nervous system: clinical and neuropathologic perspective]

The peripheral nervous system is a classic target organ in systemic vasculitis. In addition, the skeletal muscle can also be affected. Myalgia, muscle weakness and sensory deficits are typical signs, which can lead to severe functional limitations and impaired of quality of life. Vasculitic involvement of the skeletal muscle (vasculitic myopathy [VM]) and peripheral nerves (vasculitic neuropathy [VN]) occurs predominantly in polyarteritis nodosa and small-vessel vasculitis. VM presents with elevated markers of inflammation and is typically characterized by immobilizing myalgia with normal creatine kinase activity and diffuse or patchy areas of hyperintensity on T2-weighted MRI ("MRI myositis without myositis"). In VN, sensor motor deficits predominantly affect the lower extremity in the area supplied by several peripheral nerves (e.g., mononeuritis multiplex) with acute to subacute history. The histopathological examination of nerve and muscle biopsies is the gold standard for the diagnosis of vasculitic manifestations and has a significant impact on the therapeutic approach.

Cryoglobulinemia concurrent with Leishmania infantum infection in a dog and its interference with two automated hematology analyzers

A 6-year-old, intact male English Bulldog presented for evaluation of weakness. Physical examination revealed mildly pale mucous membranes and ophthalmologic alterations. A complete blood cell count was performed on the Urit Smart V5 and the Sysmex XN-1000V, and showed several hematologic discrepancies between the analyzers. The Urit reported marked leukocytosis and thrombocytosis, and the Sysmex reported marked thrombocytosis on the impedance and optical RET channel but mild thrombocytopenia on the optical PLT-F channel. On the blood smear examination, there was an abundant proteinaceous material compatible with cryoglobulins. The red blood cell exhibited a notable degree of poikilocytosis. The number of leukocytes was found to be correlated with the Sysmex total white blood cell count, while the platelet count demonstrated a better correlation with the optical PLT-F channel from the Sysmex. Centrifugation of the blood in a capillary tube (at room temperature) identified a cryoglobulin precipitate. Additionally, the blood was reanalyzed soon after warming it to 37°C, which partially corrected most of the interferences. The serum protein electrophoresis demonstrated a marked hyperproteinemia with mild hypoalbuminemia and a marked hypergammaglobulinemia. On diagnostic imaging, a mild splenomegaly was noted. Cytology of the spleen showed Leishmania infantum infection, plasma cell hyperplasia, and extramedullary hematopoiesis. This is the first description of a dog infected with Leishmania. infantum with concurrent monoclonal hypergammaglobulinemia and cryoglobulinemia. We present a detailed description of the interference of cryoglobulin with the Urit Smart V5 and the Sysmex XN-1000V, along with the usefulness of Sysmex PLT-F in this condition.

Leukocytoclastic Vasculitis: Distinguishing Drug-Induced From Hepatitis C-Related Causes

This report presents the case of a 34-year-old female with chronic cholecystitis and hepatic failure due to alcohol use and hepatitis C. She also has a history of opioid and alcohol use disorders. Frequent hospitalizations for fluid overload culminated in her presentation with lower extremity swelling and palpable purpura. Investigation revealed leukocytoclastic vasculitis, initially raising concern for mixed cryoglobulinemia from hepatitis C but ultimately more likely due to drug-induced vasculitis. This case highlights the diagnostic challenge of differentiating between hepatitis C-associated mixed cryoglobulinemia and drug-induced vasculitis, emphasizing the need for thorough evaluation to guide appropriate management.

Successful treatment of type I cryoglobulinemia with a combination of carfilzomib, cyclophosphamide, and dexamethasone: a case report and literature review

Type I cryoglobulinemia is typically associated with hematological malignancies such as B-cell lymphomas and plasma cell neoplasms. Its treatment basically targets underlying hematological malignancies, and the prognosis remains unsatisfactory. Despite several reports of type I cryoglobulinemia treated with bortezomib-based regimens, little is available on the treatment of bortezomib-resistant cases. We report a case of severe type I cryoglobulinemia associated with plasma cell neoplasm, refractory to bortezomib and daratumumab, which was successfully managed with a combination of carfilzomib, cyclophosphamide, and dexamethasone (KCd therapy). No sign of relapse has been seen for more than 3 years with maintenance therapy with ongoing carfilzomib. This case highlights the potential efficacy of carfilzomib-based regimens in bortezomib-resistant type I cryoglobulinemia, offering a promising option for cases refractory to conventional treatments.

Diagnosis and management of monoclonal gammopathy of renal significance: A British Society for Haematology good practice paper

This guideline provides consensus opinion on the investigations required for people presenting with suspected monoclonal gammopathy of renal significance to both nephrology and haematology physicians. The guideline discusses the principles of treating a patient with MGRS and provides recommendations for both supportive management and haematological therapy. It details the recommended on-going monitoring required for both specialty areas.

An interference in bilirubin detection: Pulmonary marginal zone lymphoma presenting monoclonal cryoglobulin

Marginal zone lymphoma (MZL) of the lung is an indolent B-cell lymphoma. The peripheral blood of most patients with pulmonary MZL contains low or undetectable monoclonal immunoglobulin (M protein) levels. In this case, the clinical laboratory discovered that the pulmonary MZL patient not only associated with high concentration of monoclonal IgG-type protein but also exhibited obvious gel formation characteristics that interfered with clinical biochemistry tests. Thus, the role of M protein in total bilirubin determination was examined in this study. Total bilirubin detection curve difference comparison between monoclonal IgG protein and polyclonal immunoglobulin, interference experiments, and dilution elimination experiments were conducted. These experiments revealed not only a positive correlation between M protein interference in bilirubin detection with its concentration, but also M protein-specific interference distinct from polyclonal immunoglobulin. We employed the R and EmpowerStat statistical systems to evaluate the correlation between serum monoclonal protein and total bilirubin absorbance curve data. Multivariate analysis revealed a nonlinear correlation between with globulin (GLB) and square root transformed curve optical density (OD) data. The receiver operating characteristic (ROC) curve analysis indicated an area under the curve (AUC) of 0.852 for the GLB ≥ 31.9 g/L subgroup using combined curve indicators. Our findings can enhance clinical M protein screening and scientific assessment of the populations requiring serum protein electrophoresis testing, thereby reducing the rate of missed diagnoses in the M protein population.

Rheumatoid factor levels indicate cryoglobulinemia severity in hepatitis B e antigen-negative hepatitis B virus carriers: a 7-year prospective cohort study

BACKGROUND

The phenotype of cryoglobulinemia in hepatitis B virus (HBV) carriers remains elusive.

METHODS

A 7-year prospective cohort of 648 hepatitis B e antigen (HBeAg)-negative Taiwanese HBV carriers [males: 344 (53%)] was conducted.

RESULTS

Among 648, 189 (29.2%) had cryoglobulinemia, and 26 (4.0%) had cryoglobulinemic syndrome (CS). More females; higher levels of rheumatoid factor (RF), immunoglobulin M (IgM) and fibrosis-4 indices; higher proportions of proteinuria, hematuria and hepatocellular carcinoma; and lower levels of quantitative HBsAg, C3, C4 and eGFR were noted in patients with than in those without cryoglobulinemia. The associations were RF levels with cryoglobulinemia (cutoff > 12.55 IU/mL), and RF levels and baseline autoimmune diseases with CS. CS patients, symptomless cryoglobulinemia patients and patients without cryoglobulinemia had the highest, moderate, and lowest RF levels, respectively. A greater percentage of mixed cryoglobulins [IgG (2 +), IgM (2 +) and IgA (1 +)] was noted in cryoglobulinemia patients with than in those without CS (11.5% vs. 0.81%, p = 0.002). Among the 7 CS patients treated with nucleos(t)ide analogues (Nucs), cryoglobulinemia disappeared in 3 and symptoms improved in 5 during therapy. The CS prevalence was highest (6%) in patients with a baseline age of 31-40 years. Among the 26 CS patients, 23 (88.5%), 20 (76.9%), and 16 (61.5%) had peripheral neuropathy, articular and skin involvement, respectively. The cumulative incidences of major outcomes and mortality did not differ between patients with and without cryoglobulinemia.

CONCLUSIONS

The prevalence rates of cryoglobulinemia and CS in HBeAg-negative HBV carriers were 29.2% and 4.0%, respectively. RF levels correlate with cryoglobulinemia severity. Mixed cryoglobulins of IgG (2 +), IgM (2 +) and IgA (1 +) are likely linked to CS, which might be alleviated by Nucs in some patients. The impact of cryoglobulinemia on long-term outcomes might be negligible.

Identification of Key Predictors of Cryoglobulinemia Severity at Diagnosis: Threshold, Type, and Severity Score at Diagnosis

Background: Cryoglobulinemia (CG) syndrome is a heterogeneous condition characterized by the presence of cryoglobulins in serum, often leading to vasculitis with protean clinical manifestations. Understanding the presentation of cryoglobulinemia-related symptoms based on cryoprecipitate levels, GC type, and severity at diagnosis is essential for effective management. Hence, this study aimed to provide a comprehensive analysis of patients with positive cryoglobulin detection to investigate these aspects. Methods: We conducted a retrospective review of clinical charts from patients with positive cryoglobulin detection at Colmar Hospital between May 2015 and April 2019. Results: Among 166 patients with positive cryoglobulins, the median cryoprecipitate value was 37 mg/L [IQR: 25-70], with 62% of patients below the 50 mg/L threshold. High cryoprecipitate levels were associated with C-virus hepatitis (p = 0.0007), increased fatigue (p = 0.001), fever (p = 0.0013), weight loss (p = 0.028), and musculoskeletal symptoms (p = 0.002). These patients also exhibited decreases in complement fractions (p-values 0.017 to 0.006). At the end of the one-year follow-up, they required frequent renal replacement therapy (p < 0.0001) and had a higher mortality rate (p = 0.02). Based on the CG type, patients with type I GC had splenomegaly (p = 0.039) and hemopathy (p = 0.001). According to severity at initial presentation, the severe patients had more purpura (p < 0.001), Raynaud's phenomenon (p = 0.039), and leukocytoclastic vasculitis on skin biopsy (p < 0.001), along with higher cryoprecipitate levels (p = 0.011). Multivariate analysis identified purpura (OR: 10.25), hematological malignancy (OR: 7.06), Raynaud's phenomenon (OR: 6.41), and cryoprecipitate levels (OR: 1.02) as significant markers of disease severity serving for the development of a severity score for clinical practice. Conclusions: This study identifies severity markers in patients with positive cryoprecipitate and proposes a score related to severity at diagnosis.

Successful treatment with bortezomib for refractory cryoglobulinemic vasculitis triggered by ischemic non-obstructive coronary artery disease

Type I and mixed cryoglobulinemic vasculitis differ in pathophysiology, clinical presentation, and therapeutic response. We report a case of refractory cryoglobulinemic vasculitis diagnosed following ischemic non-obstructive coronary artery disease (INOCA). The patient presented with dyspnea, as well as abdominal pain due to ischemic enteritis, purpura, and renal failure requiring dialysis. Despite the patient's IgG λ-type monoclonal gammopathy of undetermined significance (MGUS) and negative hepatitis C virus, the presence of rheumatoid factor (RF) activity and the possibility of IgM involvement were suggested by cryoglobulin analysis and strong glomerular IgM deposition. The condition was diagnosed as mixed cryoglobulinemia, and various immunomodulatory treatments, including methylprednisolone, rituximab and plasmapheresis, were administered without achieving cryoglobulin negativity. However, treatment with bortezomib and dexamethasone ultimately led to cryoglobulin negativity and clinical improvement although the patient was not weaned off dialysis, resulting in remission of the cryoglobulinemic vasculitis. This case suggests that bortezomib, a proteasome inhibitor, may be a promising treatment for refractory cryoglobulinemic vasculitis.

Causal Mediation Analyses for the Natural Course of Hepatitis C: A Prospective Cohort Study

BACKGROUND

Hepatitis C virus (HCV) infection is a systemic disease. However, the relative contribution of intrahepatic and extrahepatic diseases to mediating HCV-induced mortality is unclear, albeit critical in resource allocation for reducing preventable deaths. To this end, this study comprehensively quantified the extent to which intrahepatic and extrahepatic diseases mediate HCV-induced mortality.

METHODS

A community-based cohort study with >25 years of follow-up was conducted in Taiwan. HCV infection was profiled by antibodies against HCV and HCV RNA in participants' serum samples. The cohort data were linked to Taiwan's National Health Insurance Research Database to determine the incidences of potential mediating diseases and mortality. We employed causal mediation analyses to estimate the mediation effects of HCV on mortality in relation to the incidences of 34 candidate diseases.

RESULTS

In 18,972 participants with 934 HCV infection, we observed that 54.1% of HCV-induced mortality was mediated by intrahepatic diseases, such as liver cirrhosis and liver cancer, and 45.9% of mortality was mediated by extrahepatic diseases. The major extrahepatic mediating diseases included septicemia (estimated proportion of HCV-induced mortality mediated through the disease: 25.2%), renal disease (16.7%), blood/immune diseases (12.2%), gallbladder diseases (9.7%), and endocrine diseases (9.6%). In women, hypertension (20.0%), metabolic syndrome (18.9%), and type 2 diabetes (17.0%) also mediated HCV-induced mortality. A dose-response relationship of HCV viral load was further demonstrated for the mediation effect.

CONCLUSION

Both intrahepatic and extrahepatic manifestations mediated approximately half of HCV-induced mortality. The mediation mechanisms are supported by a dose-response relationship of HCV viral load.

Changes in Serum Rheumatoid Factor Following Eradication of Hepatitis C Virus Infection With Interferon or Direct Antiviral Therapy

Hepatitis C virus (HCV) infection is associated with a myriad of extrahepatic manifestations (EHM), as well as the production of autoantibodies, including rheumatoid factor (RF). This study aims to elucidate whether serum levels of RF change before and after HCV eradication, and whether these changes differ according to the type of therapy used. This is a retrospective cohort study of adults with chronic HCV infection treated with interferon-free or interferon-based regimens. All patients had HCV viremia at baseline and documented sustained virological response (SVR) 12 or 24 weeks after completing treatment. We measured the serum levels of RF at baseline and at SVR-12 or -24 to analyse the changes after eradication. This study enrolled 297 patients (median age, 59 years; female, 48.5%; cirrhosis, 16.8%). Among them, 78 (26.3%) were RF-positive by qualitative serology at baseline. This number decreased to 49 (16.5%) at SVR-12 or -24 (p < 0.001). Quantitatively, the median RF also decreased from 1.6 IU/mL (interquartile range [IQR], undetectable-15.8) to undetectable (IQR, undetectable-6.6 IU/mL) (p < 0.001). Significant reductions were observed in both groups. The proportion with RF seropositivity decreased from 24.3% to 15.4% (p = 0.001) in patients treated with interferon-free agents (n = 214) and from 31.3% to 19.3% (p = 0.006) in patients treated with interferon-based regimens (n = 83), without significant difference between two groups (p = 0.40). Serum RF decreased after HCV eradication, regardless of treatment regimen. Our findings suggest that HCV eradication may attenuate HCV-related autoimmunity.

Preceding hepatitis B virus infection is highly prevalent in patients with neuromyelitis optica spectrum disorder in Taiwan

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system, characterized by pathogenic anti-Aquaporin-4 antibodies (AQP4-Ab). Given that infections can trigger autoimmune responses, we investigated the association between Hepatitis B virus (HBV) infection and NMOSD.

METHODS

HBV and hepatitis C virus serologies were analyzed in 105 NMOSD patients, 85 multiple sclerosis (MS) patients, and 1,661 healthy Taiwanese controls. Participants were classified into four HBV infection statuses (acute, chronic, resolved, and never infected), and further grouped by vaccination status. Logistic regression was used to estimate odds ratios (OR) for NMOSD development in individuals with chronic or resolved HBV infection.

RESULTS

Among those born before the Taiwan's universal vaccination program, 63.4 % of NMOSD patients had resolved HBV infection, compared to 30.6 % of MS patients and 16.4 % of controls. Resolved HBV infection was associated with a 2.3-fold increased risk for NMOSD development (95 % CI, 1.4-3.8), but not with MS risk. In the post-vaccination cohort, resolved HBV infection remained more frequent in NMOSD patients (8.7 %) than in MS (0 %) and controls (1.8 %). NMOSD patients with resolved HBV infection had later disease onset by 14.6 years and higher Expanded Disability Status Scale (EDSS) scores compared to those without HBV infection, even after adjusting for age and sex (3.5 ± 1.9 vs. 2.2 ± 1.8, p < 0.001).

CONCLUSION

Preceding HBV infection is prevalent among Taiwanese NMOSD patients and is associated with increased disease risk, older age at onset, and greater disability. Screening for HBV is essential for NMOSD patients, particularly in endemic regions.

Clinical and Serological Profiles in Cryoglobulinemia: Analysis of Isotypes and Etiologies

Objectives: Cryoglobulinemia (CG) is marked by abnormal immunoglobulins (Ig) in serum, precipitating at temperatures below 37 °C. Current classification categorizes CG into three subtypes (types I, II, and III) based on Ig clonality. The features distinguishing patients with CG based on their etiology remain unidentified. Aiming to characterize clinical and serological profiles of CG individuals, we conducted an observational analysis of a large cohort of patients and compared their characteristics based on underlying causes: hepatovirus (HV) infections, rheumatic diseases (RD), hematological disorders, and unidentified etiology (essential CG). Methods: We analyzed 252 cryoglobulin-positive serum samples from 182 patients and classified these into the four etiological groups. A separate sub-analysis was carried out for 10 patients meeting criteria for multiple diseases. We collected demographic, clinical, and laboratory data: CG characterization, complement (C3 and C4) levels, antinuclear antibodies (ANA), and rheumatoid factor (RF). Kruskal-Wallis and Wilcoxon-Mann-Whitney U-tests were used for comparisons. Results: Most patients (93.3%) had mixed cryoglobulinemia (types II + III), with 6.7% having type I. HV infection, predominantly hepatitis C, was the main (52.9%) associated condition within the cohort, followed by rheumatic (27.3%) and hematological (9.8%) disorders. In our cohort, ANA were frequent (45.3%) and often associated with RF positivity (43.6%) and decreased complement levels (C3: 42.4%, C4: 32.5%). Essential CG and CG associated with RD had a higher prevalence of cutaneous manifestations (p < 0.01) and renal involvement (p = 0.017). Hematological disorder-related CG showed higher cryoglobulin and RF concentrations (p < 0.01), despite milder symptoms. Conclusions: Our study underscores a mixed prevalence of CG across disease subgroups, with hepatitis-C virus as the primary factor, followed by rheumatic and hematological disorders. Four clinical and serological profiles of CG were identified based on their etiologies.

Isolated Lower Limb Vasculitis Following SARS-CoV-2 Infection: A Case Report

Vasculitis is an autoimmune disease defined by inflammation within blood vessels, typically manifesting systemically with multi-organ complications and clinical features. Isolated vasculitis itself, however, is extremely rare and not characteristically based on the pathophysiology of the condition. Whilst there have been cases of isolated vasculitis in large-medium vessels (e.g. the aorta, subclavian, axillary, and/or femoral arteries) documented in the literature, vasculitis isolated to medium to smaller vessels is much more infrequent and is the primary focus of the following case report. We present a case of a 70-year-old male three weeks post-severe acute respiratory syndrome coronavirus 2, presenting with nausea, loss of appetite, eight kilograms of weight loss, and bilateral anterior knee pain resulting in significant functional decline and requiring the use of a four-wheel walking frame. After extensive screening for pathological causes, the most significant findings were elevated C-reactive protein, erythrocyte sedimentation rate, and white cell count with a predominant neutrophilia. Numerous forms of imaging were undertaken, with fluorodeoxyglucose-positron emission tomography suggestive of vasculitis in medium and small vessels within the bilateral lower limbs. The patient was commenced on prednisolone and later methotrexate, with complete resolution of symptoms three and a half months later. Symptom resolution was compared with repeat fluorodeoxyglucose-positron emission tomography, which also demonstrated the resolution of lower limb vasculitis changes. In the absence of other identified precipitants, as well as with the patient having a continuously elevated multiplex polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 during admission, it outlines a unique situation of such an infection being a potential trigger for isolated vasculitis in medium to small vessels. As this is not well expressed in the literature, it provides a basis for further research, whilst also assisting in the work-up of other patients who may present similarly.

The Interplay of Chronic Hepatitis C and COVID-19: Implications for Prognosis and Treatment

Introduction Chronic hepatitis C (CHC) remains a significant public health concern due to both hepatic and extrahepatic manifestations associated with substantial morbidity and mortality. The emergence of SARS-CoV-2 has raised concerns about the outcomes of COVID-19 in CHC patients. Method We conducted a retrospective analysis of patients with CHC and SARS-CoV-2 infection admitted to a tertiary care hospital between 2020 and 2023. We performed a global analysis of the entire batch of patients and, later, we evaluated the patients according to the severity of the SARS-CoV-2 infection Results The cohort included 89 patients (63 females, 26 males) with a median age of 65 years. Most patients were hospitalized in 2021. Common clinical manifestations included fever, cough, digestive symptoms, and headache. The most frequent comorbidities were renal disease, thyroid disorders, and cancer. Univariate logistic regression analysis identified older age, hospitalization in 2021, and respiratory failure as risk factors for severe COVID-19. Elevated lactate dehydrogenase levels were also associated with an increased risk of severe COVID-19. Regarding CHC, detectable hepatitis C virus viremia was associated with more severe liver disease (p<0.01). Conclusion Patients with CHC and SARS-CoV-2 infection have a substantial risk of severe outcomes. Early identification and management of these patients are crucial to improve their prognosis.

Cryoglobulinemic vasculitis triggered by Staphylococcus aureus endocarditis with chronic hepatitis C virus co-infection: a case report and literature review

Infective endocarditis is a rare but life-threatening condition, occasionally linked to diverse immunologic manifestations, including mixed cryoglobulinemia. This can lead to cryoglobulinemic vasculitis, which has the potential for widespread organ damage. Although some cases have highlighted the relationship between infective endocarditis and cryoglobulinemic vasculitis, no comprehensive epidemiological evaluation or optimal treatment strategies have been advanced for such a combination. We present a case of methicillin-sensitive Staphylococcus aureus infective endocarditis associated with cryoglobulinemic vasculitis and conduct a literature review to compare management and outcomes in similar cases. Our patient presented with classical Meltzer's triad and mild renal involvement. Cryoimmunofixation confirmed type III cryoglobulinemia, and serum cytokines showed elevated IL-6 levels. The differential diagnosis included infective endocarditis and chronic active hepatitis C virus infection. Rapid symptom resolution after antibiotic treatment identified infective endocarditis as the likely cause of cryoglobulinemic vasculitis. Our case and review of the literature highlight that early identification of the cause of cryoglobulinemic vasculitis is crucial for selecting appropriate treatment and preventing recurrence or morbidity.

Paraprotein-Mediated Glomerular Diseases

Paraproteinemias are a group of complex diseases associated with an overproduction of a monoclonal immunoglobulin that can cause a diversity of kidney disorders and end-organ damage. In this review, we focus on paraprotein-mediated glomerular diseases. Kidney biopsy plays a crucial role in diagnosing these disorders, enabling the identification of specific histological patterns. These lesions are categorized into organized (such as amyloidosis, immunotactoid glomerulopathy, fibrillary glomerulonephritis, cryoglobulinemic glomerulonephritis, and monoclonal crystalline glomerulopathies) and nonorganized deposits (such as monoclonal Ig deposition disease and proliferative glomerulonephritis with monoclonal Ig deposits) based on the characteristics of immunofluorescence findings and the ultrastructural appearance of deposits on electron microscopy. This review aims to provide an update, highlight, and discuss clinicopathological aspects such as definition, epidemiology, clinical manifestations, mechanisms of kidney injury, histological features, and diagnostic procedures.

Post-Treatment Occurrence of Serum Cryoglobulinemia in Chronic Hepatitis C Patients

BACKGROUND

Persistent cryoglobulinemia after the completion of antiviral treatment is an important consideration of clinical management in chronic hepatitis C patients. We aimed to investigate the occurrence of serum cryoglobulinemia in chronic hepatitis C patients without cryoglobulinemia at the initiation of antiviral treatment.

METHODS

In total, 776 patients without cryoglobulinemia were assessed for serum cryoglobulinemia after the completion of anti-HCV treatment. Serum cryoglobulinemia precipitation was assessed upon both the initiation and the completion of the treatment and analyzed for the clinical laboratory factors associated with chronic hepatitis C.

RESULTS

One hundred eighteen (118) patients were checked for serum cryo-precipitation after the completion of the treatment, and eight patients (4.6%) were positive for serum cryoglobulinemia. The patients who tested positive for cryoglobulinemia included a higher proportion of liver cirrhosis patients (4/50%, p = 0.033) and other organ cancer patients (5/62.5%, p = 0.006) than patients who showed no signs of cryoglobulinemia after treatment. In a multivariate analysis, liver cirrhosis (odds ratio [OR]-17.86, 95% confidence interval [95% CI]-1.79-177.35, p = 0.014) and other organ cancer (OR-25.17 95% CI-2.59-244.23, p = 0.005) were independently and significantly associated with positive cryoglobulinemia 3 months after antiviral treatment.

CONCLUSIONS

Three months after the antiviral DAA therapy had concluded, eight patients tested positive for cryoglobulinemia, representing a 6.7% prevalence. Liver cirrhosis and other organ cancer were independently and significantly associated with positive cryoglobulinemia after antiviral treatment. Further investigation into the causes of positive cryoglobulinemia after DAA antiviral therapy is warranted.

Case report: BTK inhibitors is effective in type II mixed cryoglobulinemia with wild-type MyD88

This study presents two cases of type II mixed cryoglobulinemia. One case is essential, while the other is presumably associated with hepatitis B virus (HBV) infection. Both patients tested positive for monoclonal IgMκ, but negative for MyD88 mutation. They showed resistance to rituximab combined with a glucosteroid regimen, but responded positively to BTK inhibitors. These cases highlight the remarkable effectiveness of BTK inhibitors in treating refractory type II cryoglobulinemia without MyD88 mutation. The first patient achieved rapid complete remission of nephrotic syndrome within one month of starting ibrutinib, along with a significant reduction in cryoglobulin levels and abnormal clonal cells. The second patient had a rapid disappearance of rash within three days and accelerated wound healing within one week of initiating orelabrutinib, accompanied by a reduction in C-reactive protein. However, there was no reduction in cryoglobulin levels during the 12-month follow-up. These findings suggest varied mechanisms of action of BTK inhibitors in type II cryoglobulinemia through different mechanisms.

Clinical characteristics, radiological features and outcomes in pulmonary involvement of cryoglobulinemia

BACKGROUND

Cryoglobulinemia with pulmonary involvement is rare, and its characteristics, radiological findings, and outcomes are still poorly understood.

METHODS

Ten patients with pulmonary involvement of 491 cryoglobulinemia patients at Peking Union Medical College Hospital were enrolled in this retrospective study. We analyzed the characteristics, radiological features and management of pulmonary involvement patients, and compared with those of non-pulmonary involvement with cryoglobulinemia.

RESULTS

The 10 patients with pulmonary involvement (2 males; median age, 53 years) included three patients with type I cryoglobulinemia and seven patients with mixed cryoglobulinemia. All of 10 patients were IgM isotype cryoglobulinemia. All type I patients were secondary to B-cell non-Hodgkin lymphoma. Four mixed patients were essential, and the remaining patients were secondary to infections (n = 2) and systemic lupus erythematosus (n = 1), respectively. Six patients had additional affected organs, including skin (60%), kidney (50%), peripheral nerves (30%), joints (20%), and heart (20%). The pulmonary symptoms included dyspnea (50%), dry cough (30%), chest tightness (30%), and hemoptysis (10%). Chest computed tomography (CT) showed diffuse ground-glass opacity (80%), nodules (40%), pleural effusions (30%), and reticulation (20%). Two patients experienced life-threatening diffuse alveolar hemorrhage. Five patients received corticosteroid-based regimens, and four received rituximab-based regimens. All patients on rituximab-based regimens achieved clinical remission. The estimated two-year overall survival (OS) was 40%. Patients with pulmonary involvement had significantly worse OS and progression-free survival than non-pulmonary involvement patients of cryoglobulinemia (P < 0.0001).

CONCLUSIONS

A diagnosis of pulmonary involvement should be highly suspected for patients with cryoglobulinemia and chest CT-indicated infiltrates without other explanations. Patients with pulmonary involvement had a poor prognosis. Rituximab-based treatment may improve the outcome.

An Unusual Case of Cryoglobulinemic Vasculitis and Acute Disseminating Encephalomyelitis in a 21-Year-Old Caucasian Male

Cryoglobulinemic vasculitis and acute disseminated encephalomyelitis (ADEM) are characterized by damage to either blood vessels or grey matter. For both diseases, infections can be an etiology. In cryoglobulinemic vasculitis, the initial insult causes damage to the glomerulus, and in the case of ADEM, damage leads to a central nervous system demyelinating disorder. Infective endocarditis can be associated with both diseases and can be challenging to diagnose. Individuals on antibiotics may present with negative blood cultures, making underlying infective endocarditis difficult to diagnose. In this report, we describe a 21-year-old male who presented to the hospital after an assault with splenic laceration and was subsequently found to have infective endocarditis associated with cryoglobulinemic vasculitis and ADEM.

New Biomarkers for Systemic Necrotizing Vasculitides

Systemic necrotising vasculitides (SNVs) pose significant challenges due to their diverse clinical manifestations and variable outcomes. Therefore, identifying reliable biomarkers holds promise for improving precision medicine in SNVs. This review explores emerging biomarkers aiming to enhance diagnostic accuracy, prognostic assessment, and disease monitoring. We discuss recent advances in immunological biomarkers, inflammatory indicators, and other parameters that exhibit potential diagnostic and prognostic utility. A comprehensive understanding of these biomarkers may facilitate earlier and more accurate SNV detection, aiding in timely intervention and personalized treatment strategies. Furthermore, we highlight the evolving landscape of disease monitoring through innovative biomarkers, shedding light on their dynamic roles in reflecting disease activity and treatment response. Integrating these novel biomarkers into clinical practice can revolutionize the management of SNVs, ultimately improving patient outcomes and quality of life.

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.

Extrahepatic manifestations of HCV where do we stand?

Hepatitis C virus (HCV) infection has been associated as up 40-70% of patients with extrahepatic manifestations (EHM) and 36 different syndromes. These could be attributed to the fact that HCV is lymphotropic, particularly B lymphotropic, and not merely hepatotropic, and could trigger immunological alterations indirectly by exerting a chronic stimulus on the immune system with production of immunoglobulins having rheumatoid activity forming immune complexes and production of cryoglobulins. Cryoglobulinemoa plays a pivotal role in producing most EHM of HCV such as vasculitis, glomerulonephritis, arthritis and neuropathies. Less frequently; while less frequently, the direct viral cytopathic effect could lead to EHMs independent of cryoglobulinemia. The mainstay of treatment of EMH has been antivirals, since interferon era to direct-acting drugs era, with no differences between the two eras, despite the better virological response. Longer evaluation of virological response and clinical investigation with longer follow-ups are necessary.

Cryoglobulinemia vasculitis associated with adult-onset Still's disease

Key Clinical Message

The present case indicates that cryoglobulinemia vasculitis should be considered in the differential diagnosis of purpura in patients with adult-onset Still's disease (AOSD).

Abstract

The presence of purpura is suggested in adult-onset Still's disease (AOSD) hematological complications of hemophagocytic syndrome, disseminated intravascular coagulation, or thrombotic microangiopathy. We herein report a case of AOSD complicated by cryoglobulinemia vasculitis presenting with purpura.

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.

Ocular manifestations of cryoglobulinemia: a reappraisal

BACKGROUND/OBJECTIVES

To describe frequency and type of ocular manifestations in patients with cryoglobulinemic vasculitis (CV), as well as management approaches and outcomes.

SUBJECTS/METHODS

This was a retrospective, observational, cohort study of patients who were diagnosed with CV at a single center and regularly underwent a comprehensive ocular assessment.

RESULTS

Ophthalmologic manifestations were recorded in 16 patients (28%). The diagnoses included dry eye disease and primary Sjögren syndrome in 5 and 2 patients, respectively; peripheral ulcerative keratitis and anterior scleritis in 1 patient each; hyperviscosity syndrome and hypertensive retinopathy in 2 patients each; and Purtscher- like retinopathy in 3 patients. Twelve patients (75%) were anti-HCV/HCV RNA-positive, 11 of whom achieved a sustained virologic response (SVR) following treatment with interferon-α2b plus ribavirin or direct-acting antivirals. All patients were treated with ocular lubricants. Systemic therapeutic measures, including glucocorticoids, immunosuppressive and biologic agents, induced the disappearance or ≥50% reduction of cryoglobulins and major signs of vasculitis in 11 patients (68.7%). In the remaining 5 patients (31.3%), cryoglobulins and CV manifestations remained unchanged or decreased by <50%. The corresponding ophthalmologic assessment showed a variable degree of improvement in the ocular symptoms in all but 2 patients (87.5%). The best corrected visual acuity following treatment improved in 26 eyes, was unchanged in 3 eyes, and worsened in 3 eyes.

CONCLUSIONS

Eye involvement is not a rare event in CV patients. A timely diagnosis and the correct employment of the available therapeutic measures may result in a favorable outcome of the ocular and extra-ocular manifestations.

[Secondary vasculitides]

Vasculitides that occur in association with underlying primary diseases are called secondary vasculitides. In the diverse differential diagnostics of vasculitides, a large variety of secondary vasculitides have to be considered. Secondary vasculitides cover the full spectrum of vasculitides, presenting in manifold clinical manifestations. This article provides an overview of systemic diseases and etiological factors, such as infections, drugs, and malignancies, which can be associated with vasculitides. The possible associations with infectious agents are too numerous to be comprehensively covered and are discussed in an exemplary fashion and with a western European focus. Especially in atypical and refractory disease courses, a secondary vasculitis should be considered. In light of the diversity of differential diagnoses and the particular challenges posed by secondary vasculitides, interdisciplinary collaboration is the key for an accurate and early diagnosis as well as for successful treatment management. Treatment of the primary disease should always be prioritized and, if a drug-induced vasculitis is suspected, immediate cessation of the culprit drug is mandatory.

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.

Cholestatic HCV Cryoglobulinemia: A New Clinical and Pathological Entity before and after Direct-Acting Antiviral Therapies-A Case-Control Study

Twenty-nine patients with HCV infection (HCV+) and mixed cryoglobulinemia (MC+) were retrospectively selected and matched for age and sex with 31 HCV+ MC- patients. Biomarkers of cholestasis (direct bilirubin, alkaline phosphatase, and gamma-glutamyl transferase), HCV-RNA and genotype, and plasma cryoprecipitates were measured before and after virus eradication; liver histology and plasma cells (aggregation and distribution), observed blinded by two pathologists, were analyzed. Sixty participants (mean age: 56.5; range: 35-77, males: 50%) with HCV infection were enrolled. Cholestasis (≥2 pathologically increased cholestasis biomarkers) was significantly higher in the MC group (p = 0.02) and correlated with cryoglobulinemia (OR 6.52; p = 0.02). At liver histological assessment, plasma cells were significantly increased in the MC+ group (p = 0.004) and tended to form aggregates more than the control group (p = 0.05). At multivariate analysis with MC, age, HCV-RNA, HBV diabetes, and cirrhosis, cholestasis was only significantly correlated to MC (OR 8.30; p < 0.05). In 25% patients, MC persisted after virus eradication with new antiviral treatment. Our study identified for the first time an association between MC, cholestasis, and an increased number of intrahepatic plasma cells in chronic hepatitis C (CHC) patients before virus eradication. Future studies are required to understand how MC contributes to liver damage and how its persistence affects the patients' follow-up after antiviral therapies.

Lupus nephritis with cryoglobulinemic glomerulonephritis features: a diagnostic conundrum

In this clinical case, we report an atypical and unique presentation of systemic lupus erythematosus (SLE) in a 39-year-old female with nephrotic syndrome. The patient exhibited class IV plus V lupus nephritis and extensive immune complex deposition within the intracapillary and arteriolar regions suggestive of cryoglobulinemic glomerulonephritis, despite no detectable circulating cryoglobulins. Electron microscopy revealed cryoglobulin-like deposit distribution in all glomerular examined compartments, namely subendothelial, intramembranous, subepithelial, and mesangial, apparently extending from the capillary hyaline thrombi. The case highlights the possibility of severe renal injury in SLE without circulating cryoglobulins and the diverse kidney manifestations associated with the disease. However, the impact on patient outcome was minimal, as classical treatment (id est National Institute of Health regimen) remained effective.

Efficacy of Therapeutic Apheresis for Cryoglobulinemic Vasculitis Patients with Renal Involvement: A Systematic Review

INTRODUCTION

Therapeutic apheresis (TA) is commonly used for cryoglobulinemic vasculitis (CV) patients, but its efficacy remains uncertain. This systematic review aimed to assess the efficacy of different TA modalities, such as plasma exchange (PE), plasmapheresis (PP), and cryofiltration (CF), in treating CV patients with renal involvement.

METHODS

Literature search of MEDLINE, EMBASE, and Cochrane Databases was conducted up to December 2022. Studies that reported the outcomes of TA in adult CV patients with renal involvement were assessed. The protocol for this systematic review has been registered with PROSPERO (No. CRD42023417727). The quality of each study was evaluated by the investigators using the validated methodological index for non-randomized studies (minors) quality score.

RESULTS

154 patients who encountered 170 episodes of serious events necessitating TA were evaluated across 76 studies. Among them, 51% were males, with a mean age ranging from 49 to 58 years. The CV types included 15 type I, 97 type II, and 13 type III, while the remaining patients exhibited mixed (n = 17) or undetermined CV types (n = 12). Among the treatment modalities, PE, PP, and CF were performed in 85 (56%), 52 (34%), and 17 patients (11%), respectively, with no identical protocol for TA treatment. The overall response rate for TA was 78%, with response rates of 84%, 77%, and 75% observed in type I, II, and III patients respectively. Most patients received steroids, immunosuppressants, and treatment targeting the underlying causative disease. The overall long-term renal outcome rate was 77%, with type I, II, and III patients experiencing response rates of 89%, 76%, and 90%, respectively. The renal outcomes in patients receiving PE, PP, and CF were comparable, with rates of 78%, 76%, and 81%, respectively.

CONCLUSIONS

This study presents compelling evidence that combination of TA with other treatments, especially immunosuppressive therapy, is a successful strategy for effectively managing severe renal involvement in CV patients. Among the TA modalities studied, including PE, PP, and CF, all demonstrated efficacy, with PE being the most frequently employed approach.

Hepatitis B virus-related cryoglobulinemia: Clinical characteristics, virological features, and treatment

BACKGROUND

Hepatitis B virus (HBV) infection is a rare etiology of cryoglobulinemia, and its clinical characteristics, virological features and treatment are poorly understood.

METHODS

This retrospective study enrolled 23 patients with HBV-related cryoglobulinemia from 497 cryoglobulinemia patients at Peking Union Medical College Hospital between January 2015 and February 2023. We analyzed the clinical characteristics, virological features and management of patients with HBV-related cryoglobulinemia.

RESULTS

The 23 patients (13 males; median age 48 years) were all mixed cryoglobulinemia and serological HBsAg positive, while 15 patients exhibited HBV-DNA replication. The presence of HBsAg in cryoglobulins was evaluated in 7 patients, all of whom were positive. The most commonly involved organs were kidneys (69.6%), skin (65.2%), peripheral nerves (21.7%), joints (8.7%), gastrointestinal tract (4.3%), and cardiac (4.3%). Eight patients received antiviral therapy with nucleot (s)ide analogues (NAs) alone, 12 patients received NA- and corticosteroid-based regimens, and 3 patients received NA- and rituximab-based regimens based on the severity of clinical symptoms. After a median follow-up of 44 months, four patients died, and one patient was lost to follow-up. All remaining patients (n = 18) achieved clinical remission, and HBV-DNA replication was not detected in 16 out of 18 patients. There was no HBV reactivation in patients treated with rituximab. The three-year overall survival and progression-free survival were 87.0% and 80.3%, respectively.

CONCLUSIONS

HBV-related cryoglobulinemia patients should be treated with antiviral therapy. Corticosteroids and rituximab are effective for severe cases, but patients need to be closely monitored for therapy-related infection.

Ocular complications of plasma cell dyscrasias

Plasma cell dyscrasias are a wide range of severe monoclonal gammopathies caused by pre-malignant or malignant plasma cells that over-secrete an abnormal monoclonal antibody. These disorders are associated with various systemic findings, including ophthalmological disorders. A search of PubMed, EMBASE, Scopus and Cochrane databases was performed in March 2021 to examine evidence pertaining to ocular complications in patients diagnosed with plasma cell dyscrasias. This review outlines the ocular complications associated with smoldering multiple myeloma and monoclonal gammopathy of undetermined significance, plasmacytomas, multiple myeloma, Waldenström's macroglobulinemia, systemic amyloidosis, Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy and Skin changes (POEMS) syndrome, and cryoglobulinemia. Although, the pathological mechanisms are not completely elucidated yet, wide-ranging ocular presentations have been identified over the years, evolving both the anterior and posterior segments of the eye. Moreover, the presenting symptoms also help in early diagnosis in asymptomatic patients. Therefore, it is imperative for the treating ophthalmologist and oncologist to maintain a high clinical suspicion for identifying the ophthalmological signs and diagnosing the underlying disease, preventing its progression through efficacious treatment strategies.

Approach to laboratory ordering and interpretation in rheumatology

Evaluation of suspected rheumatic disease is a significant challenge due to overlapping and sometimes non-specific clinical features. Most laboratory tests in rheumatic disease have incomplete sensitivity and specificity, leading to positive results without disease and negative results despite disease presence. Therefore, judicious ordering and correct interpretation of laboratory testing in rheumatology is critical in order to provide high-value care. Herein we review laboratory testing in rheumatology in the context of a framework for approaching rheumatic disease.

Risk factors for relapse in non-infectious cryoglobulinemic vasculitis, including type I cryoglobulinemia: a systematic review

Background

Data on non-infectious cryoglobulinemic vasculitis (NICV) is scarce, especially concerning the management of relapses, which are troublesome. We aimed to investigate risk factors for relapse in NICV.

Methods

A systematic literature search of CINAHL, Embase, MEDLINE, Scopus, and the Web of Science databases was implemented until April 2023. Eligible studies included randomized control trials, observational studies, and case series with ≥4 patients. Two reviewers independently extracted data and assessed the quality of the eligible studies.

Results

A total of 3,724 articles were retrieved from a database search, with 27 studies meeting the inclusion criteria for review. Most studies (n = 23) detailed relapses, with the time to relapse varying between 1 and 80 months. The relapse rate was reported at 28% in Type I NICV and ranged from 22% to 60% in mixed NICV. Risk factors for relapse in NICV were identified based on the cryoglobulin subtype and correlated with clinical and immunological responses to varying treatment regimens. Type I NICV with an associated lymphoproliferative disorder exhibited a response-relapse pattern. Cutaneous and articular involvement and incomplete clinical and immunological responses to treatment, particularly corticosteroid monotherapy and occasionally rituximab, influence the risk of relapse in Type II and Type III NICV.

Conclusion

Our findings underscore the significance of attaining both clinical and immunological responses and identifying risk factors for relapse in NICV. Appropriate risk stratification for NICV patients is essential for the successful implementation of effective treatment strategies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023408140.

Type II Cryoglobulinemic Membranoproliferative Glomerulonephritis Caused by Mucosa-associated Lymphoid Tissue Lymphoma

A 67-year-old man complained of lower limb edema with a purpuric skin rash. Laboratory tests revealed proteinuria, elevated serum creatinine levels, and low serum albumin levels. The patient was also positive for cryoglobulin in serum, immunoglobulin (Ig) M gammopathy, hypocomplementemia, and rheumatoid factor. He was negative for anti-hepatitis C virus antibodies. A pathological analysis of the renal tissue revealed membranoproliferative glomerulonephritis, common histological features of cryoglobulinemic vasculitis (CV), and mucosa-associated lymphoid tissue lymphoma invasion. Although hematologic malignancy is a rare cause of type II CV, these clinical findings suggest that mucosa-associated lymphoid tissue lymphoma (MALT) lymphoma may have been the cause in the present case.

The "Viral" Form of Polyarteritis Nodosa (PAN)-A Distinct Entity: A Case Based Review

Classic polyarteritis nodosa (PAN) is a vasculitis with systemic manifestations that is characterized by inflammatory and necrotizing lesions affecting medium and small muscular arteries, most frequently at the bifurcation of the vessels. These lesions lead to the formation of microaneurysms, hemorrhaging ruptured aneurysms, thrombosis, and, consequently, ischemia or organ infarction. Background and Objectives: We present a complex clinical case of a patient with a late diagnosis of polyarteritis nodosa with multiorgan involvement. Materials and Methods: The 44-year-old patient, in an urban environment, presented on her own in the emergency room for acute ischemia phenomena and forearm and right-hand compartment syndrome, requiring surgical decompression in the Plastic Surgery Clinic. Results: Significant inflammatory syndrome is noted, alongside severe normocytic hypochromic iron deficiency anemia, nitrogen retention syndrome, hyperkalemia, hepatic syndrome, and immunological disturbances: absence of cANCA, pANCA, anti Scl 70 Ac, antinuclear Ac, and anti dDNA Ac, as well as a low C3 fraction of the plasmatic complement system. The morphological aspect described in the right-hand skin biopsy correlated with the clinical data supports the diagnosis of PAN. Conclusions: The viral form of PAN seems to be individualized as a distinct entity, requiring early, aggressive medication.

CLEC18A Impairs Phagocytosis by Reducing FcγRIIA Expression and Arresting Autophagosome-Lysosome Fusion

Mixed cryoglobulinemia (MC) is a hepatitis C virus (HCV)-related extrahepatic manifestation that is characterized by the abnormal presence of immune complexes (ICs). This may be due to the reduced uptake and clearance of ICs. The C-type lectin member 18A (CLEC18A) is a secretory protein that is expressed abundantly in hepatocytes. We previously observed that CLEC18A increased significantly in the phagocytes and sera of patients with HCV, particularly those with MC. Herein, we explored the biological functions of CLEC18A in the MC syndrome development of patients with HCV by using an in vitro cell-based assay with quantitative reverse transcription-PCR, immunoblotting, immunofluorescence, flow cytometry, and enzyme-linked immunosorbent assays. HCV infection or Toll-like receptor 3/7/8 activation could induce CLEC18A expression in Huh7.5 cells. Upregulated CLEC18A interacts with Rab5 and Rab7 and enhances type I/III interferon production to inhibit HCV replication in hepatocytes. However, overexpressed CLEC18A suppressed phagocytic activity in phagocytes. Significantly decreased levels of the Fc gamma receptor (FcγR) IIA were found in the neutrophils of HCV patients, particularly in those with MC (P < 0.005). We demonstrated that CLEC18A could inhibit FcγRIIA expression in a dose-dependent manner through the production of NOX-2-dependent reactive oxygen species to impair the uptake of ICs. Additionally, CLEC18A suppresses the Rab7 expression that is induced by starvation. Overexpressed CLEC18A does not affect autophagosome formation but does reduce the recruitment of Rab7 to autophagosomes, thereby retarding the maturation of autophagosomes and affecting autophagosome-lysosome fusion. We offer a novel molecular machinery with which to understand the association of HCV infection with autoimmunity and propose that CLEC18A may act as a candidate biomarker for HCV-associated MC. IMPORTANCE During infection, the host immune system produces cellular factors to protect against pathogen invasion. However, when the immune response overreacts and there is dysregulated cytokine homeostasis, autoimmunity occurs following an infection. We identified a cellular factor that is involved in HCV-related extrahepatic manifestation, namely, CLEC18A, which is expressed abundantly in hepatocytes and phagocytes. It inhibits HCV replication in hepatocytes by interacting with Rab5/7 and enhancing type I/III IFN expression. However, overexpressed CLEC18A inhibited FcγRIIA expression in phagocytes to impair phagocytosis. Furthermore, the interaction between CLEC18A and Rab5/7 may reduce the recruitment of Rab7 to autophagosomes and thereby retard autophagosome maturation and cause immune complex accumulation. A decreasing trend in CLEC18A levels that was accompanied by reduced HCV RNA titers and diminished cryoglobulin was observed in the sera of HCV-MC patients after direct-acting antiviral therapy. CLEC18A may be used for the evaluation of anti-HCV therapeutic drug effects and could be a potential predisposing factor for the development of MC syndrome.

Article Topic: Neuropathies Due to Infections and Antimicrobial Treatments

Purpose of eview

The aim of this review is to discuss the presentation, diagnosis, and management of polyneuropathy (PN) in selected infections. Overall, most infection related PNs are an indirect consequence of immune activation rather than a direct result of peripheral nerve infection,  Schwann cell infection, or toxin production, though note this review will describe infections that cause PN through all these mechanisms. Rather than dividing them by each infectious agent separately, we have grouped the infectious neuropathies according to their presenting phenotype, to serve as a guide to clinicians. Finally, toxic neuropathies related to antimicrobials are briefly summarized.

Recent findings

While PN from many infections is decreasing, increasing evidence links infections to variants of GBS. Incidence of neuropathies secondary to use of HIV therapy has decreased over the last few years.

Summary

In this manuscript, a general overview of the more common infectious causes of PN will be discussed, dividing them across clinical phenotypes: large- and small-fiber polyneuropathy, Guillain-Barré syndrome (GBS), mononeuritis multiplex, and autonomic neuropathy. Rare but important infectious causes are also discussed.

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.