Cryoglobulins

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Cryoglobulins

• Dr. An-Wen Chan
• Rheumatology Rounds
• Tuesday August 17, 2004

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History

• 27 yo Black female from East Africa
• RFC ?lupus nephritis
• PMHx
• 1) 1999 Sicca, ?Sjogrens. 0.83L, ANA, RF
  (540)
• 2) April 2004 Raynauds with digital infarcts
• 0.48L, ANA (1640), -dsDNA/ENA, cryos, low C3
  C4
• 3) Infertility

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History physical exam

• Meds
• None
• HPI
• 4 week Hx of diarrhea, fever, malaise
• to hospital pericardial effusion, Cr 150
• hemoptysis
• to ICU for hypoxic respiratory failure
• Physical exam
• noncontributory

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Laboratory tests

• Hgb 125, WBC 12.4 (0.23L), platelets 98
• Cr 155, U/A blood, WBCs
• Normal lytes, LFTs
• ESR 25
• Serology
• ANA (1640), RF 335, cryoglobulins
• dsDNA, anti-GBM, ANCA, Hep B/C
• Low C3, low C4
• Renal biopsy Diffuse prolif GN
• Cryos on EM

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Summary

• 27 F with pulmonary-renal syndrome consistent
  with cryoglobulinemic vasculitis.
• Course in ICU
• improved renal function with pulse steroids,
  PLEX
• recurrent pulmonary hemorrhage with steroid
  tapering
• daily oral cyclophosphamide added (1.5mg/kg)
• today still ventilated, Cr 100, -cryoglobulins

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Lupus nephritis

• WHO Classification
• I. Normal glomeruli
• II. Pure mesangial alterations
• III. Focal segmental GN
• IV. Focal proliferative GN (worst prognosis)
• V. Diffuse GN
• VI. Advanced sclerosing GN
• diagnosis is important for treatment and
  prognosis

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Treatment of lupus nephritis

• Systematic review (Flanc RS et al, Cochrane
  Library 2004)
• 25 eligible RCTs with biopsy-proven DPLN (909
  patients)
• CYC or azathioprine (n12)
• PLEX (n7)
• Cyclosporine (n2)
• MMF, misoprostol, IVIG, methylprednisolone
• Variable quality
• Allocation concealment (12)
• Blinding (8)
• Intention-to-treat analysis (56)

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Efficacy data - Total mortality
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Efficacy data - ESRD
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Efficacy data - Doubling of creatinine
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Safety data - Major infections
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Safety data - Ovarian failure
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Results summary

• CYC reduced risk of doubling Cr increased risk
  of ovarian failure
• Azathioprine reduced overall mortality
• Neither had significant effect on ESRD or major
  infection
• Overall, no significant difference in efficacy
  between CYC and azathioprine
• PLEX not shown to be useful

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Pulse vs continuous CYC

• Austin et al (1986)
• Parallel group, 5-arm, unblinded RCT of 38
  patients
• Interventions Prednisolone plus
• 1) Pulse CYC (0.5-1g/m2 IV q3mths)
• 2) Continuous CYC (up to 4mg/kg po od)
• 3) Azathioprine
• 4) CYC and azathioprine
• 5) Nothing
• Median follow-up 3 years

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Pulse vs continuous CYC

• Yee et al (2004) - EULAR trial
• Parallel group, 2-arm, unblinded RCT of 32
  patients
• Interventions 1) Pulse CYC
• 10mg/kg IV q3wks x 4,
• then po q4wks x 9mths,
• then po q6wks x 12 mths
• 2) Continuous CYC (2mg/kg po od x 3mths)
• steroid, followed by Aza steroid
• Median follow-up 3 years

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Pulse vs continuous CYC Trial quality

• Poor quality
• Unclear allocation concealment
• Unblinded
• Allow rescue Rx (performance bias)
• Small sample size
• Not ITT

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Pulse vs continuous CYC Trial results
Austin (1986) EULAR trial (2004)
Continuous Pulse Continuous
Pulse n18 n20
n16 n13 Mortality 7 4
1 2 ESRD 4 1 2
0 Neutropenia - - 3
1 Infections 3 2 4 5 Ovarian
failure 7/10 8/17 1 1 Hemorr.
cystitis 3 0 1 0
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Pulse vs continuous CYC - further data
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Conclusions

• Despite limited trial data, cyclophosphamide and
  azathioprine have been shown to improve outcomes
  in lupus nephritis
• Cyclophosphamide steroids is considered 1st
  line treatment, with an effect on creatinine but
  not ESRD/mortality
• Optimal dosing regimen remains unclear, although
  pulse cyclophosphamide may have fewer adverse
  effects

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Cryoglobulins Brouet classification

• Immunoglobulins /- complement that precipitate
  from serum in the cold and redissolve on
  rewarming
• Type I (5-25)
• monoclonal Ig (IgM, IgG IgA, light chain)
  fractions
• Observed in MM, Waldenstroms
• Hyperviscosity/ thrombosis

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Cryoglobulins

• Type II (60) mixed
• polyclonal IgG and monoconal IgM or IgA
  rheumatoid factor activity against the Ig
• Essential MC
• HepC chronic infection, HIV
• EBV, HepB
• Type III (25-30)
• both IgG and RF IgM are polyclonal
• SLE, lymphoproliferative malignancies, HCV, CTDz
  (Sjogren)

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Cryoglobulins

• Physiologic vs pathologic (chronic immune
  stimulation, augmented IC formation, decreased IC
  clearance)
• Deposition of antigen-antibody complexes in
  small/ medium-sized arteries-vasculitis
• Mixed Cryo HepC related (95)
• Anti HCV antibodies
• HCV RNA in the plasma and cryoprecipitate
• Polyclonal IgG anti-HCV Abs within the
  cryoprecipitate
• Virus binds B lymphocytes via CD 81, lowering
  the activation threshold , facilitating
  lymphoproliferation, production of
  autoantibodies?

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Clinical Manifestations

• Palpable purpura (LEUE)
• Nonspecific systemic symptoms
• Arthralgias
• Lympadenopathy
• Hepatosplenomegaly
• Peripheral neuropathy
• Low C4

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Renal Disease

• 20 of patients at the time of diagnosis
• Asymptomatic hematuria and proteinuria, low
  complement and N creatinine, HBP
• ARF, nephrotic syndrome less common
• Eventually occurs in 35 to 60 of patients with
  type II disease, 12 in type III

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Renal Disease

• Thickening of the GBM and cellular proliferation
  (MPGN)
• Specific findings
• Intraluminal thrombi composed of precipitated
  cryoglobulins on light microscopy
• Diffuse IgM deposition in the capillary loops on
  IF
• Subendothelial deposits, fingerprint pattern

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Renal Disease

• Thickening of the GBM and cellular proliferation
  (MPGN)
• Specific findings
• Intraluminal thrombi composed of precipitated
  cryoglobulins on light microscopy
• Diffuse IgM deposition in the capillary loops on
  IF
• Subendothelial deposits, fingerprint pattern

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MPGN (PAS microthrombi, hypercellular)
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Diagnosis

• History, purpura, low C4,
• Demonstrating circulating cryoglobulins
• Cryocrit
• Immunofixation, double diffusion in agar for type
  of abnormal protein
• Chemical quantification
• Biopsy

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Treatment

• Indications for active therapy are organ
  threatening disease (ARF, amputation, advanced
  neuropathy)
• Type I- Rx underlying malignancy
• Type II/III Plasmapheresis/Steroids/Cyclophosphami
  de, Antiviral, ?Rituximab

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Plasmapheresis

• Plasmapheresis (to remove the circulation
  cryoglobulins)
• Steroids (1000 mg of intravenous
  methylprednisolone daily times three, followed by
  conventional oral prednisone)
• Cyclophosphamide to prevent new antibody
  formation
• ?steroids enhance HCV replication

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Plasmapheresis

• Uncontrolled observations 15 patients (DAmico et
  al. 1984)
• reduction in the plasma creatinine concentration
  in 55 to 87 of patients
• 4-39 Rx needed, average 13

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Plasmapheresis

• Rx
• Eexchange one plasma volume three times weekly
  for two to three weeks

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PlasmapheresisEfficacy

• Changes in the percent cryocrit after
  plasmapheresis do not correlate closely with
  clinical activity
• Percent solubility of the cryoglobulins at 37ºC
  or a decline in the temperature at which the
  cryoproteins precipitate may be a better index of
  the response to therapy (not commonly performed
  tests)

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PlasmapheresisEfficacy

• Successful plasmapheresis should
• lead to rapid resolution of purpuric lesions
• Return toward baseline if there has been a recent
  elevation in the plasma creatinine concentration
• signs of neuropathy are not likely to remit
  during short-term therapy.

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Antiviral Therapy

• ?-interferon has been recommended in MC patients
  with HCV induced viremia
• Randomized trial (Misisani et al. NEJM
  1994330751)
• HCV RNA fell to undetectable levels in 60 of
  patients in the ?-interferon group
• Improvement in the cutaneous vasculitis,
  cryoglobulin titers, and in the plasma creatinine
  concentration

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Antiviral Therapy

• All who responded relapsed upon D/C of
  ?-interferon
• Anecdotal observations of reversal of MPGN after
  ?-interferon

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Antiviral Therapy

• Evidence for efficacy of combination IFN
  ribavirin in HepC MC
• Case series of 9 patients refractory to IFN alone
  (Zuckerman et al. J Rheumatol 2000 27 2172)
  cryo decreased, skin vasculitis, symptoms
  improved
• Pegylated IFN ribavirin recommended if no CRF
  contraindication.

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Antiviral Therapy

• ?-interferon immunostimulating activity may
  aggravate renal disease and vasculitic lesions?
  use in patients with low-grade kidney
  involvement, delay 2-4 months in severe disease
  Rxed with PLEX immunosuppression (?unable to
  clear HepC anyway)

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Rituximab

• Human/mouse chimeric antiCD20 Ab
• Interferes with B cell autoimmunity unknown
  mechanism
• Eliminates peripheral CD20 B lymphocytes
• Total IgG and IgA unchanged, IgM moderately
  decreased
• Well tolerated, rare allergic reaction
• Case reports of use in mixed type II

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Rituximab

• Zaja et al. Blood 2003 1013827-3834
• 14 consecutive type II MC (12 HCV related, all
  HIV-, 1 Sjogren, 2 essential)
• Cutaneous vasculitis improved in all, RF, cryo,
  steroid use decreased in all treated
• Proteinuria improved in 1 patient with MPGN
• No serious infection, 1 patient had retinal
  artery thrombosis NYD

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Rituximab

• Sansonne et al. Blood 2003 1013818
• 20 patients mixed cryo resistant to IFN Rx
• Rituximab q week for 4 weeks 80 response
  initially, 12 in remission at one year
• HepC viral levels doubled in responders however

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Rituximab

• Arzo et al. Ann Rheum Dis 2002 61922-924
• Case report 71F essential type II MC (HepC-)
• Palpable purpura6y, neuropathy 2y
• ARF postop-BxMPGN, cryocrit 1.7, RF 396
• Rx prednisone 60 4 months- no response
• Rx Rituximab qweek6 weeks, crea down to 120,
  cryo neg., improved purpura/neuropathy, 8 month
  remission