144: Cryoglobulinemia & Cryofibrinogenemia Flashcards
What are cryoglobulins and how do they behave in serum or plasma?
Cryoglobulins are circulating immunoglobulin complexes found in plasma or serum that reversibly precipitate in cold temperatures. They can be asymptomatic or cause a clinical syndrome involving the skin, such as purpura or ulceration.
What are the classifications of cryoglobulinemia according to Brouet?
Cryoglobulinemia is classified into three types:
- Type I: Consists of a single monoclonal immunoglobulin (typically IgG or light chain).
- Type II: Mixed cryoglobulinemia with polyclonal immunoglobulin (typically IgG) and monoclonal components.
- Type III: Composed of purely polyclonal immunoglobulin, often associated with chronic inflammatory states.
What is the epidemiology of mixed cryoglobulinemia?
Mixed cryoglobulinemia has an incidence of 1 to 7 in 100,000, with a higher prevalence in Southern Europe due to the geographic distribution of HCV. The average age at onset is 54 years, and it is associated with chronic HCV infection in over 90% of cases.
What are the clinical associations of essential mixed cryoglobulinemia?
Essential mixed cryoglobulinemia is associated with:
- Infectious diseases (75%)
- Autoimmune diseases (24%)
- Hematologic diseases (7%)
It occurs without an identifiable cause and has a male-to-female ratio of 1:3.
What are the clinical implications of symptomatic cryoglobulinemic vasculitis syndrome in HCV patients?
Symptomatic cryoglobulinemic vasculitis syndrome occurs in 2% to 5% of patients with chronic HCV infection. This condition is characterized by immune complex-mediated vasculitis affecting the skin, neural, and renal tissues, highlighting the need for careful monitoring in HCV patients.
What is cryoglobulinemia?
The presence of circulating immunoglobulin complexes in plasma or serum that reversibly precipitate in cold temperatures.
What is the average age at onset for essential mixed cryoglobulinemia?
54 years.
What is the prevalence of mixed cryoglobulinemia?
1 to 7 in 100,000.
What is the association of mixed cryoglobulinemia with chronic HCV infection?
The vast majority of mixed cryoglobulinemias occurs in association with chronic HCV infection (>90%).
What are the clinical implications of cryoglobulinemia?
It can be asymptomatic or cause a clinical syndrome involving the skin, such as purpura and ulceration.
What is the significance of Type I cryoglobulins?
Type I cryoglobulins consist of a single monoclonal immunoglobulin and are associated with hematologic malignancies.
What is the difference between Type II and Type III cryoglobulins?
Type II cryoglobulins are mixed and associated with chronic inflammatory states, while Type III cryoglobulins are associated with chronic HCV or connective tissue disease.
What percentage of chronically HCV-infected subjects develop cryoglobulinemia?
30%, which can increase to 90% in patients with longstanding disease.
What is the most common cause of mixed cryoglobulinemia?
The most common cause is chronic HCV infection, associated with >90% of cases.
What are the clinical implications of Type I cryoglobulinemia and how does it differ from Types II and III?
Type I cryoglobulinemia consists of a monoclonal immunoglobulin (typically IgG or light chain) and can lead to occlusive vasculopathy. In contrast, Types II and III are referred to as mixed cryoglobulinemias, often associated with chronic inflammatory states and can involve polyclonal immunoglobulins.
What is the epidemiological significance of mixed cryoglobulinemia in relation to chronic HCV infection?
Mixed cryoglobulinemia has a notable epidemiological significance, particularly in Southern Europe, where it is linked to the geographic distribution of HCV.
How does the presence of cryoglobulins in a patient’s serum relate to the clinical presentation of cryoglobulinemia?
The presence of cryoglobulins in a patient’s serum can be asymptomatic or lead to occlusive vasculopathy, known as cryoglobulinemic syndrome.
What are the most common cutaneous findings in patients with cryoglobulinemic vasculitis?
The most common cutaneous findings include:
- Type I: Often asymptomatic; may present with infarction, hemorrhagic crusts, ulcers, and lesions on the head and oral or nasal mucosa.
- Type II and III: Cryoglobulinemic vasculitis with intermittent orthostatic palpable purpura, sporadic isolated petechiae or erythematous macules.
What are the non-cutaneous findings associated with mixed cryoglobulinemias?
The most common extracutaneous manifestations include:
- Weakness
- Arthralgias
- Arthritis
Additionally, the Meltzer Triad consists of:
- Purpura
- Arthralgias
- Weakness
What renal complications are associated with cryoglobulinemic vasculitis?
Renal complications include:
- Incidence: 5-60% of patients
- Common findings:
- Hematuria with or without renal insufficiency (41%)
- Isolated proteinuria
- Nephrotic syndrome (21%)
What neurological symptoms are associated with mixed cryoglobulinemia?
Neurological symptoms can include:
- Sensory peripheral nervous system issues secondary to epineural vasculitis
- Paresthesias with burning symptoms in the lower limbs.
What musculoskeletal symptoms are prevalent in patients with cryoglobulinemia?
Musculoskeletal symptoms include:
- 70% of patients experience arthralgias and myalgias, predominantly in Type II and III.
What pulmonary complications can arise in patients with cryoglobulinemia?
Pulmonary complications can include:
- 40% of patients may experience dyspnea, cough, or pleuritic pain.
What is the most frequent manifestation of patients with mixed cryoglobulinemias?
Weakness, arthralgias, or arthritis.
What is a common neurologic manifestation in patients with mixed cryoglobulinemia?
Peripheral neuropathy, which can occur in up to 80% of patients.
What is the Meltzer triad associated with mixed cryoglobulinemias?
Purpura, arthralgias, and weakness.
What are the pulmonary manifestations seen in patients with mixed cryoglobulinemia?
Dyspnea, cough, or pleuritic pain, with pulmonary function tests showing small airways disease.
What is the hallmark histopathologic finding in mixed cryoglobulinemia?
Livedo vasculitis (LCV).
What is a significant renal finding in patients with mixed cryoglobulinemia?
Hematuria with or without renal insufficiency.
A patient presents with purpura, arthralgias, and weakness. What is the likely diagnosis and what is this triad called?
The likely diagnosis is mixed cryoglobulinemia, and the triad is called Meltzer’s triad.
A patient with cryoglobulinemia presents with renal involvement. What is the most common renal pathology associated with mixed cryoglobulinemia?
Membranoproliferative glomerulonephritis (MPGN) is the most common renal pathology associated with mixed cryoglobulinemia.
What is the hallmark histopathologic finding in mixed cryoglobulinemia?
Leukocytoclastic vasculitis (LCV) is the hallmark histopathologic finding in mixed cryoglobulinemia.
What is the most common extracutaneous manifestation of mixed cryoglobulinemias?
The most common extracutaneous manifestations are weakness, arthralgias, or arthritis.
What is the most common pulmonary finding in patients with cryoglobulinemia?
The most common pulmonary findings are dyspnea, cough, or pleuritic pain.
What is the characteristic fundoscopic finding in Type I cryoglobulinemia?
The characteristic finding is ‘sausaging,’ which refers to retinal venous engorgement.
What is the most common cutaneous finding in cryoglobulinemia?
The most common cutaneous finding is palpable purpura.
What is the most common neurologic manifestation of mixed cryoglobulinemia?
The most common neurologic manifestation is sensory peripheral neuropathy.
What is the most common renal complication in mixed cryoglobulinemia?
The most common renal complication is membranoproliferative glomerulonephritis (MPGN).
What are the most common cutaneous findings in patients with Type I cryoglobulinemic vasculitis?
- Often asymptomatic
- Infarction, hemorrhagic crusts, ulcers, and lesions on the head and oral or nasal mucosa (more common in Type I than mixed cryoglobulinemia)
What are the common non-cutaneous findings in patients with mixed cryoglobulinemias?
- Weakness
- Arthralgias
- Arthritis
- MELTZER TRIAD (25-30% of patients): Purpura, arthralgias, weakness
What percentage of patients with mixed cryoglobulinemia experience renal involvement, and what are the common renal manifestations?
- Incidence: 5-60%
- Common manifestations include:
- Hematuria with or without renal insufficiency (41%)
- Isolated proteinuria
- Nephrotic syndrome (21%)
- Acute nephritic syndrome
What neurological symptoms are associated with mixed cryoglobulinemia, and what is the prevalence of peripheral neuropathy in these patients?
- Neurological symptoms include:
- Sensory peripheral nervous system issues secondary to epineural vasculitis
- Paresthesias with burning symptoms in the lower limbs
- Peripheral neuropathy in up to 80% of patients with mixed cryoglobulinemia (prevalence of only 5% to 45% in symptom-based studies)
What are the pulmonary manifestations observed in patients with mixed cryoglobulinemia?
- 40% of patients experience:
- Dyspnea, cough, or pleuritic pain
- Pulmonary function tests indicating small airways disease
- CXR may show interstitial infiltrates or signs of subclinical alveolitis
- Uncommon pulmonary vasculitis and severe pulmonary disease (e.g., BOOP)
What are the main types of cryoglobulinemia and their associations with HCV infection?
- Type I: Associated with hematologic disorders, particularly Non-Hodgkin B-cell lymphoma.
- Essential mixed cryoglobulinemia: Occurs without underlying disease in a minority of patients.
-
Mixed cryoglobulinemia:
- Serum anti-HCV antibodies and/or HCV RNA found in 70-100% of patients.
- Type II is more strongly associated with HCV than Type III (90% vs 70%).
- Cryoglobulins are found in 55-90% of patients with longstanding HCV infection, with overt syndrome developing in only 2-5% of these cases.
What are the clinical features that suggest a diagnosis of cryoglobulinemia?
The possibility of diagnosis is suggested by:
- Purpura of the distal extremities
- Acral cyanosis
- Necrosis
What laboratory testing procedures are recommended for diagnosing cryoglobulinemia?
Laboratory testing should include:
1. Cryoglobulin testing: Establishing the diagnosis when positive.
2. Complete blood count: Including differential.
3. Serum biochemistry: To assess liver disease or other conditions.
4. Serum must be obtained in warm tubes at 37°C in the absence of anticoagulants.
5. Temperature should be kept at 37°C until laboratory processing.
What are the associations of HCV with cryoglobulinemia and related conditions?
HCV is associated with:
- Longstanding infection
- Old age
- Type II cryoglobulins
- Higher cryoglobulin levels
- Clonal B-cell expansion (t(14;18) translocation with bcl-2 rearrangement)
- HCV-associated cryoglobulinemic vasculitis syndrome: Increased mortality risk, especially in patients with Sjögren syndrome and SLE.
What are the common hematologic disorders associated with Type I cryoglobulinemia?
Type I cryoglobulinemia is commonly associated with:
- Hematologic disorders
- Non-Hodgkin B-cell lymphoma, which is the most frequently encountered hematologic malignancy.
What is the relationship between HCV infection duration and the presence of cryoglobulins?
The presence of cryoglobulins increases with the duration of HCV infection:
- Cryoglobulins are found in 55% to 90% of patients with longstanding infection.
- Overt cryoglobulinemic syndrome develops in only 2% to 5% of these cases.
What factors may predispose individuals to extrahepatic systemic manifestations of cryoglobulinemia?
Individuals with HLA-DR11 or HLA-DR6 may be predisposed to extrahepatic systemic manifestations of cryoglobulinemia.
What are the mandatory laboratory tests for diagnosing cryoglobulinemia?
Mandatory laboratory tests for diagnosing cryoglobulinemia include:
1. Cryoglobulin testing (should be positive)
2. Complete blood count, including differential
3. Serum BUN
4. Liver function tests
5. ANA, SSA, and SSB (to rule out associated conditions)
6. Consider histology for further evaluation if necessary.
What clinical features suggest a diagnosis of cryoglobulinemia?
The possibility of diagnosing cryoglobulinemia is suggested by:
- Presence of purpura of the distal extremities
- Acral cyanosis
- Necrosis
What is the significance of Type II cryoglobulinemia in relation to HCV?
Type II cryoglobulinemia is more strongly associated with HCV than Type III, with a prevalence of 90% compared to 70% respectively.
What is the most frequently encountered hematologic malignancy associated with Type I cryoglobulinemia?
Non-Hodgkin B-cell lymphoma.
What percentage of cryoglobulinemic patients have serum anti-HCV antibodies and/or HCV RNA?
70-100%.
How is Type II cryoglobulinemia related to HCV?
It is more strongly associated with HCV than Type III (90% vs 70%).