The Histopathologic Spectrum of Cryofibrinogenemia in Four Anatomic Sites

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

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

Analysis of cryoproteins with a focus on cryofibrinogen: a study on 103 patients

OBJECTIVES

Cryofibrinogen (CF) is an abnormal protein in plasma that precipitates at 4 °C and dissolves at 37 °C. Whilst serum cryoglobulins (CGs) analysis is common practice, CF investigation is rarely performed. This study aims to describe the testing methodology developed at our laboratory, potential pitfalls for all analytical phases, the distribution among hospital wards and clinical conditions underlying test requests and clinical conditions in which to order CF analysis is useful.

METHODS

Retrospective analysis of laboratory samples received between January 2019 and June 2021 with CF testing requests.

RESULTS

A complete protocol for CF pre-analytical, analytical and post-analytical phases are supplied. Most test requests were received from the rheumatology department for systemic sclerosis or liver transplant screening. Among the 103 in-patients included, CF+ was confirmed in 68 patients (66%). Of observed CF+ patients (n=68) most cases were CGs- (n=44, 67%). Isolated CF was found in 43% of the cases. Among CF- patients (n=35; 34%) only 2 patients had positive CGs (CGs+). Among rheumatology patients (n=66), isolated CF+ was observed in 45% (n=30/66), whilst among patients with systemic sclerosis with CF+ (n=19), isolated CF+ was detected in 79% (n=15/19).

CONCLUSIONS

Described analytical procedures may be used for the creation of harmonized recommendations and indications for CF analysis. Isolated CF positivity among hospitalized patients, predominantly rheumatology and systemic sclerosis patients, appears higher than rates previously reported in literature. We propose CF test recommendations should be included in investigation protocols for diseases where cryofibrinogenemia may occur.

Cryofibrinogenemia: What Rheumatologists Should Know

Cryofibrinogenemia refers to the presence of cryofibrinogen in plasma. This protein has the property of precipitating at lower temperatures. Cryofibrinogenemia is a rare disorder, clinically characterized by skin lesions, such as ulcers, necrosis, livedo reticularis, arthralgia, thrombosis, and limb ischemia. These features are most often observed in rheumatological practice and consist in the differential diagnoses of antiphospholipid syndrome, primary vasculitis, thrombotic thrombocytopenic purpura, and cryoglobulinemia. Classical histopathological findings include the presence of thrombi within the lumen of blood vessels of the skin without vasculitis. To date, there are no validated classification criteria. Management includes corticosteroids, immunosuppressive therapy, anticoagulants, and fibrinolytic agents. This narrative review aims to make physicians, particularly rheumatologists, aware of existence of this underdiagnosed condition. There are no epidemiological studies evaluating the prevalence of cryofibrinogenemia in different rheumatological disorders. Studies are also required to investigate if certain features of rheumatological diseases are related to the presence of cryofibrinogenemia.

High prevalence of cryofibrinogenemia in patients with chilblains during the COVID-19 outbreak

BACKGROUND

Many cutaneous manifestations have been described in possible association with the COVID-19 pandemic, including acral lesions resembling chilblains. The underlying pathomechanisms of COVID-19 chilblains are not fully understood. The aim of this study was to describe the clinical, pathological, and laboratory findings of a series of patients who developed chilblains during the COVID-19 outbreak and to investigate the possible factors that could be involved in the pathogenesis of these lesions.

METHODS

We conducted a prospective cohort study that included 54 patients who presented with chilblains during the highest peak in the incidence of COVID-19 in Cantabria (northern Spain). Skin biopsies were performed on 10 of these patients who presented with recent lesions. Laboratory investigations, including immunological analysis, serological studies, and the assessment of cryoproteins, were also performed.

RESULTS

Most patients presented erythematous plaques located on the toes and/or purpuric macules located on the feet. Histopathological findings were compatible with those of idiopathic chilblains. Immunohistochemical evaluation showed C3d and C4d deposits in the vessel walls in seven cases. The autoimmunity panel was negative in most of our series. Cryoprotein testing showed positive cryofibrinogen in two-thirds (66.7%) of the patients assessed. On follow-up, most patients presented almost complete resolution, although six patients required prednisone and antiaggregant drug treatment.

CONCLUSIONS

This study shows, for the first time to our knowledge, a high prevalence of cryofibrinogenemia in patients with chilblains during the COVID-19 pandemic. Cryofibrinogenemia could be implicated in the pathogenesis of chilblains related to COVID-19.

Characteristic electron-microscopic features of cryofibrinogen-associated glomerulonephritis: a case report

Background

Cryofibrinogenemia is a rare disorder that mainly affects the skin and occasionally the kidney. However, there are few published reports of cryofibrinogenemia-associated renal pathology. We therefore report a patient with cryofibrinogen-associated glomerulonephritis. Samples from this patient were examined by electron microscopy, laser microdissection, and liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Case presentation

A 78-year-old Japanese man presented with declining renal function, proteinuria, and gross hematuria. Kidney biopsy showed a membranoproliferative pattern with crescent formation and dominant C3c deposition in which subendothelial deposits with uniquely organized electron-microscopic features were observed. Additional ultrastructural analysis of cryoprecipitates extracted from plasma revealed similar structures of the glomerular subendothelial deposits. LC-MS/MS identified an increase in fibrinogen α, β, and γ chains, fibronectin, filamin-A, and C3. The glomerular lesions were diagnosed as cryofibrinogen-associated glomerulonephritis on the basis of these findings.

Conclusions

Although there are few reports of cryofibrinogen-associated glomerulonephritis, we believe that accurate diagnosis can be achieved by performing LC-MS/MS and ultrastructural analysis.

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

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

Diagnosis and classification of granulomatous myositis

The term granulomatous myositis is applied to a myopathic syndrome associated with non-specific epithelioid granulomas in striated muscle. This rare entity is most frequently related to sarcoidosis, but other uncommon causes have been reported, including an idiopathic form only after systemic disorders known to cause similar myopathological abnormalities have been excluded. Symmetrical proximal or distal muscle weakness is the rule in the clinical presentation, sometimes associated with dysphagia. Although the clinical profile together with electromyography (EMG) studies may be useful, definite diagnosis requires pathological examination. Systemic glucocorticoids are the treatment of choice, but the clinical outcome is not always satisfactory.

Cryofibrinogenemia

Cryofibrinogenemia is a cryoprotein that was first identified in 1955 by Korst and Kratochvil. Unlike cryoglobulin, the precipitate forms only in plasma and not in the serum. The presence of cryofibrinogen in plasma can be asymptomatic. Cryofibrinogenemia is considered a rare disorder: its prevalence varies from 0% to 7% in healthy subjects and from 8% to 13% in hospitalized patients. Nevertheless, cryofibrinogenemia, when a cryopathy is clinically suspected, has been reported in 12% to 51% of patients. Skin manifestations are usually the first signs and are usually moderate; in addition, cold intolerance, Raynaud phenomenon, purpura, or livedo reticularis often occurs. Skin necrosis, acral ulcers, and gangrene can lead to surgery and amputation. Systemic manifestations are common, and arterial or venous thrombotic events are frequent. Cryofibrinogenemia may be primary (essential) or secondary to other underlying disorders, such as carcinoma, infection, vasculitis, collagen disease, or associated with cryoglobulinemia. The histological features of cryofibrinogenemia can confirm the presence of cryofibrinogen within small and medium arteries, plus occlusive thrombotic diathesis composed of eosinophilic refractile deposits within vessel lumina. Cryofibrinogenemia is a treatable and potentially reversible disease.In moderate forms, it can be treated by simply avoiding cold temperatures. The use of corticosteroids in association with low-dose aspirin is the treatment of choice for moderate forms, although stanozolol is an alternative maintenance therapy. Immunosuppressive therapies, plasmapheresis, and/or intravenous fibrinolysis are useful at treating severe forms of cryofibrinogenemia. The use of anticoagulants is limited to the management of thrombotic events. Treatment of secondary cryofibrinogenemia involves the management of associated diseases. Regular follow-ups are needed because of the high risk of recurrence. Moreover, up to half of patients with cryofibrinogenemia considered as essential may develop lymphomas in the following years. Compared with cryoglobulinemia, less is known about cryofibrinogenemia. Its diagnosis should be considered when suggestive clinical manifestations are present and when there are specific biopsy findings. Although identification of cryofibrinogen in blood samples is simple and inexpensive, cryofibrinogenemia can be asymptomatic, and a lack of diagnosis criteria can make diagnosis difficult to confirm. This review describes the clinical manifestations and the biological and pathological features and discusses the criteria used to diagnose and manage cryofibrinogenemia.

[Cutaneous manifestations revealing cryofibrinogenaemia associated with monoclonal gammopathy]

BACKGROUND

Cryofibrinogenaemia is an under-recognized cutaneous thrombotic vasculopathy that may be revealed by purpura or chronic necrotic ulcerations. We report two original cases characterized by their severity, their association with a monoclonal gammopathy and their excellent response to treatment.

PATIENTS

A 38-year-old woman was admitted for large necrotic leg ulcers appearing 1 year earlier and already investigated. Non-specific signs were seen on a previous skin biopsy and the diagnosis of a factitious disorder was considered at that time. Further investigations revealed circulating cryofibrinogen associated with IgG kappa monoclonal gammopathy without cryoglobulinaemia. Plasmapheresis followed by bortezomid-dexamethasone to treat the monoclonal gammopathy resulted in rapid and complete healing of the ulcers, militating in favour of its involvement in cryofibrinogen formation. The second patient, a 91-year-old woman, was referred to our department for acute necrotic purpura of the legs. Skin biopsy revealed leukocytoclastic vasculitis. Glomerular nephropathy with acute renal failure and multiple arterial thromboses were associated with the skin condition. The cryofibrinogen assay was positive without cryoglobulinaemia and other causes of vasculitis were ruled out. The main component was monoclonal IgG lambda. Prednisone-cyclophosphamide treatment led to complete healing of the skin lesions and to recovery from the systemic consequences of cryofibrinogen without sequelae.

CONCLUSION

Routine screening for cryofibrinogen in plasma should be performed to explore cutaneous symptoms of unexplained thrombotic vasculopathy, even in the presence of a non-specific skin biopsy. Specific treatment of cryofibrinogenaemia associated monoclonal gammopathy appears to be highly effective against manifestations of cryofibrinogenaemia.

Unusual causes of cutaneous ulceration

Skin ulceration is a major source of morbidity and is often difficult to manage. Ulcers caused by an inflammatory cause or microvascular occlusion are particularly challenging in terms of diagnosis and treatment. The management of such ulcers requires careful assessment of associated systemic conditions and a thorough analysis of the ulcer's clinical and histologic findings. In this article, the authors discuss several examples of inflammatory ulcers and the approach to the diagnosis and treatment of these ulcers.