1. Tuesday Case

2. History
Pt is a 70 yo man originally presented to the ER on 12/20/07 c/o SOB x 3 days with increasing LE edema. Pt has a h/o CKD, asthma, HTN, CHF, CAD, AS w/porcine AVR 2001, HCV, chronic normocytic anemia thought 2/2 HCV and CKD.
Pt has been admitted several times over the past year for similar reasons, including to the ICU in 11/07 for CHF which required a lasix drip for diuresis.
Pt reported non-compliance w/meds 2/2 diarrhea for 4 days PTA. Non bloody, yellow-brown well formed diarrhea x 4 days. No fevers/chills, n/v, melena or brbpr. Denies use of NSAIDs.
Pt was diuresed in the ICU, given blood transfusions, and started on vanco for a resistant staph epidermis UTI and was transferred to the floor 12/22.
On 12/26/07, renal consulted for patient’s worsening CKD (crt from 1.5 baseline to 2.8) with nephrotic range proteinuria. Renal bx on 1/8/08.

3. PMHx Renal Heme CVS Pulm: asthma GI CKD stage 3 Normocytic anemia GU
baseline creatinine of ~1.5
Nephrotic syndrome
Heme
Normocytic anemia
CVS
HTN
CHF (EF 38%, 11/07)
CAD s/p PCI 7/06, prox LAD
AVR 2001, porcine
Pulm: asthma GI
Hep C, gen 1a
PUD
EGD: erythematous gastropathy
Colonoscopy: single polyp, diverticulosis, internal hemorrhoids GU
BPH
Hematuria - cystoscopy 3/07 neg, 4/06 with inflammation
Rheum
Skin rash - 11/07 Leukocytoclastic Vasculitis
arthalgia

4. SocH: FamH: Lives alone
tobacco: ex-smoker (1-2 packs/week, quit 4 years ago)
ETOH: alcohol 1-2x/wk, quit 4 yrs ago
DRUGS: former crack-cocaine use, several episodes of IVDU 30 yrs ago
FamH:
all relatives died of "old age" - denies liver/renal disease

5. Physical Exam General: elderly, thin, in NAD HEENT: anicteric, perrl
NECK: no lad, no jvd
HEART: rrr, s1s2, 2/6 systolic murmur
LUNGS: mild bibasilar crackles
ABDOMEN: nl bs, soft, nt/nd, +hepatomegaly, no splenomegaly, no fluid wave
SKIN: no stigmata of cirrhosis
EXTREMITIES: 2+ edema with scrotal swelling, chronic stasis changes
EXTREMITIES: 1+ edema

6. Lab Data

7. Differential Diagnosis
Patient with
active sediment (proteinuria and hematuria)
HTN, edema, … pulmonary edema
Nephrotic syndrome
Anasarca, nephrotic proteinuria, hypoalbuminuria
Low Complement GN
SLE
Endocarditis
PIGN
Cyroglobulinema (HCV, arthralgia, leukocytoclastic vasculitis)
MPGN (HCV)

8. LM MICRO -13 glomeruli, one globally sclerotic
-all glomeruli are enlarged and hypercellular and have a lobulated appearance
-hypercellularity is mostly due to proliferation of endothelial cells and
mesangial cells and occasional marginating inflammatory cells
-occasional double contours are also noted
-podocytes are acutely injured and reveal diffuse hypertrophy
-tubulointerstitial compartment is remarkable for extensive interstitial
fibrosis, accompanied by patchy dense inflammatory infiltrate of lymphocyte,
monocytes and rare plasma cells
-the few non-atrophic tubules are mildly hypertrophic and occasionally reveal a
flattened epithelium and contain hyaline casts.
Arterioles are generally unremarkable
Trichrome: blue represent collagen = fibrosis / sclerotic glomeruli
Sclerotic glomeruli and atropic tubules

9. IF IF
--renal cortex containinf our glomeruli, two of which are gloabbbly sclerotic
-there is 1-2+ diffuse background for IgG, IgM shows 3+ segmental semilinear
staining in the glomerular basement membranes
-numberous intrtubular casts are noted within IgA, and kappa and lambda light
chains
-C3 shows similar pattern of positive stain in the glomeruli with 3+ segmental
semilinear staining in the glomerular basement membranes.
-fibrinogen is diffusely positive in interstitial capillaries
-C1q and albumin are negative

10. EM EM -tissue with renal cortex containing a single glomeruli
-GBM are remarkable for the presence of double contours due to interposition of
mesangial cell cytoplasm
-podocytes are acutely injured and reveal extensive foot process effacement
accompanied by microvillous transformation
-numerous electron dense deposits are noted in the mesangial areas as well as in
the capillary walls, within the double contours
-no tubuloreticular inclusions are identified although endothelial cells appear
occasionally swollen.
Electron dense material is also noted inlumina of interstitial capillaries

11. EM
Electron dense material is also noted inlumina of interstitial capillaries

12. How should we treat this patient?

13. Hepatitis C virus-related cryoglobulinemia and glomerulonephritis
pathogenesis and therapeutic strategies

14. Introduction HCV HCV related disease: cryoglobulinemia and MPGN
Treatment for our patient
Standard antiviral (IFN-alpha and Ribavirin)?
IFN-alpha?
CG targeted treatment?

15. HCV virus HCV is an RNA virus of the flaviviridae family
170 million persons infected worldwide
The natural targets of HCV are hepatocytes and, possibly, B lymphocyte

16. The HCV Genome and Expressed Polyprotein
Figure 1. The HCV Genome and Expressed Polyprotein.
Two regions in E2, called hypervariable regions 1 and 2 (HVR 1 and HVR 2), show extreme sequence variability, which is thought to be the result of selective pressure by virus-specific antibodies.
HCV encodes a single polyprotein of 3011 amino acids, which is then processed into 10 mature structural and regulatory proteins (Fig. 1).
a capside protein, two envelope proteins (E1 and E2) and seven non-structural proteins involved in the viral life cycle
The region of the envelope protein E2 contains the binding site for CD81, a tetraspanin expressed on hepatocytes and B lymphocytes that is thought to function as a cell receptor or co-receptor of the virus. As the natural targets of HCV are hepatocytes and B lymphocytes, the identification of CD81 provides a mechanism by which these cells are infected by HCV.
Viral replication, which occurs through a direct RNA-RNA mechanism without a DNA intermediate and genomic integration, is highly error-prone, resulting in the generation of different but related variants known as quasispecies.
This genetic variability confers to the virus an important survival advantage against host immune surveillance, and may contribute to the persistence of HCV infection.
N Engl J Med, Vol. 345, No. 1 July 5, 2001

17. Genotypes There are at least six major genotypes 75%
The different genotypes have different geographic distributions.
Genotypes 1a and 1b are the most common in the United States (about 75 percent of cases).
Genotypes 2 and 3 are present in only 10 to 20 percent of patients.
There is little difference in the severity of disease or outcome of patients infected with different genotypes. Knowledge of the genotype is important because it has predictive value in terms of theresponse to antivrial therapy, with better responses associated with genotypes 2 and 3 than with genotype 1.
There are at least six major genotypes

18. HCV-associated Mixed Cryoglobulinemia (MC)
Mixed cryoglobulins (MCs) are proteins that reversibly precipitate at ≤ 37°C and consist of a mixture of monoclonal or polyclonal IgM that have antiglobulin (rheumatoid factor-RF) activity and bind to polyclonal IgG.
MCs are categorized as
Type I monoclonal Igs (IgG, IgM, and sometimes IgA)
2/2 MM or Waldenström's macroglobulinemia
Type II if the IgM RF is monoclonal
2/2 persistent viral infection: HCV, HIV
Type III if polyclonal IgM RF is present
2/2 connective tissue disease
HCV involved in the pathogenesis of MC
Characterized by nonneoplastic proliferation of rheumatoid factor positive B-cell clones => CG production
p/w triad of purpura, asthenia (feeling of weakness), and arthalgia
Most common organs invovled are: skin (purpura, leg ulcers), nerves (peripheral neuropathy) and kidneys (GN)
Vessel wall deposition of circulating CG leads to complement activation, and is responsible for the vasculitic lesions and organ damage

19. Serum protein electrophoresis
LABORATORY DETECTION
Cryoglobulin precipitate in a cryocrit tube
The cryocrit is approximately 25% (left panel)
Serum protein electrophoresis (ELP) of the cryoprecipitate reveals both a homogeneous band and a smear pattern in the gamma zone,
indicating a cryoglobulin composed of monoclonal and polyclonal gamma globulins.
Immunofixation with specific antisera to the IgG, IgA, IgM, κ, and λ chains
demonstrates type II cryoglobulinemia formed by
monoclonal IgM-κ (homogenous bands in the IgM heavy chain and κ light chain lanes) and
polyclonal IgG (a smear pattern in the IgG heavy chain and κ and λ light chain lanes).
25%
Serum protein electrophoresis
Cryoglobulin precipitate in a cryocrit tube

20. Sequential steps for managing and treating patients with chronic HCV infection, genotype 1
In principle, all patients with chronic HCV infection are candidates for antiviral therapy.
However, the risks and benefits of treatment must be assessed individually, particularly given the typically slow course of natural infection.
Only a subgroup of infected persons will have a clear indication for therapy.
persistently elevated alanine aminotransferase (ALT) levels and a liver biopsy showing fibrosis or at least moderate necrosis and inflammation.
These persons have a high risk of disease progression, and treatment is strongly recommended in the absence of contraindications.
Persons with elevated alanine aminotransferase levels and only minimal or mild necrotic and inflammatory changes may also be treated.
However, the risk of progressive liver disease is lower, and follow-up by means of serial measurements of alanine aminotransferase and a biopsy at three to five years is considered a reasonable alternative
Persons with persistently normal alanine aminotransferase levels and no histologic evidence of necrotic
and inflammatory changes or only minimal changes have an excellent prognosis without therapy. In fact,
in some such persons alanine aminotransferase levels become elevated after treatment with interferon alfa
American Association for the Study of Liver Diseases. Hepatology 2004; 39:1147

21. Sustained virologic response rates with peginterferon alfa-2a (pegIFN) or interferon alfa-2b (IFN) and ribavirin (RBV) according to genotype

22. Contraindications to Treatment with Iterferon Alfa and Ribavirin
Side Effects of Treatmetn with Interferon Alfa and Ribavirin
Renal Insufficiency (CrCl ~50)

23. What treatment options are available?
HCV related cryoglobulinemia and MPGN
Treatment for our patient
Standard antiviral (IFN-alpha and Ribavirin)?
IFN-alpha?
CG targeted treatment?

24. Proposed Mechanisms of Action of Interferon Alfa against HCV
Interferon alfa is a cytokine that has an important function in the innate antiviral immune response.
It acts by attaching to cell-surface receptors
that signal through the system of Janus-activated kinase and signal transducers and activators of transcription,
leading to induction of multiple interferon stimulated genes (Fig. 1).
These genes include double-stranded RNases, inhibitors of viral protein translation, and proteins that destabilize viral messenger RNA. Interferon alfa also induces the expression of genes involved in the immune response, resulting in activation of natural killer cells, maturation of dendritic cells, proliferation of memory T cells, and prevention of T-cell apoptosis
Interferon alfa engages receptors on the hepatocyte cell-surface membrane,
causing them to dimerize and to activate Janus-activated and tyrosine kinases
that phosporylate the cytoplasmic signal transducers and activators of transcription (STAT) proteins.
STAT1 and STAT2 dimerize and bind interferon regulatory factor 9 (IRF9), creating a large complex (interferon-stimulated gene factor 3, or ISGF3) that is translocated into the nucleus, where it binds to interferon-stimulated response elements (ISREs) on DNA.
This engagement causes transcription of multiple (>100) interferon-stimulated gene (ISG) mRNAs, which exit the nucleus and encode proteins that alter cell metabolism and interfere with virus replication, protein synthesis, and assembly.
Major ISGs thought to be important in inhibiting HCV replication include 2',5' oligoadenylate synthetase, which activates antiviral RNases; RNA-specific adenosine deaminase, which edits viral RNA; and protein kinase R, which inactivates protein translation from viral mRNA. The HCV replicative complex is associated with the cytoplasmic membranes of hepatocytes and comprises RNA replicative intermediates, viral mRNA, structural and nonstructural viral proteins, and assembling virions.

25. 2nd phase (not randomized)
Influence of Antiviral Therapy in Hepatitis C Virus–Associated Cryoglobulinemic MPGN (Alric, AJKD, 2004)
Patients (n=25) with nephrotoic-range proteinuria, mixed CG, MPGN by biopsy, with HCV
Initial phase
All treated for nephrotic proteinuria with lasix, acei, plasma exchanges, and steroid
2nd phase (not randomized)
Group 1, (n=18) after 4-12 weeks of initial treatment receive antiviral treatment for minimal 6 mos
Group 2, (n=7) maintenance with low dose lasix
Follow up
Initial eval, end of antiviral tx, and 6 mos after discontinuation

26. Influence of Antiviral Therapy in Hepatitis C Virus–Associated Cryoglobulinemic MPGN (Alric, AJKD, 2004)
No difference was found between groups for the parameters studied
At diagnosis of nephrotic-range proteinuria, the duration of HCV infection established on the history of patients for factors associated with HCV infection was and months for patients from groups 1 and 2, respectively.
Patients from group 1 were undistinguishable from those from group 2 concerning
serum alanine aminotransferases levels, urinary protein excretion, or serum albumin or creatinine levels
In most patients, renal failure was mild,
with mean serum creatinine concentrations of mg/dL ( mol/L) in group 1
mg/dL ( mol/L) in group 2
Only 6 of 18 patients from group 1 and 3 of 7 patients from group 2 had more severe renal disease, with a serum creatinine level greater than 1.7 mg/dL (150 mol/L).
Type II cryoglobulinemia was found in
16 of 18 patients from group 1 and in all 7 patients from group 2.
All patients had a polyclonal immunoglobulin G (IgG) and an IgM monoclonal component. Polyclonal IgM and IgG type III cryoglobulins were found in only 2 of 18 patients from group 1. Cryoglobulin levels were variable, with means of g/L (range, 0.02 to 6.8 g/L) and g/L (range, 0.02 to 2.79 g/L) in groups 1 and 2, respectively.
The most frequent HCV genotype was genotype 1 (11 of 18 patients, group 1; 4 of 7 patients, group 2). According to the Knodell index, liver disease was mild in both groups

27. Influence of Antiviral Therapy in Hepatitis C Virus–Associated Cryoglobulinemic MPGN (Alric, AJKD, 2004)
All 6 nonresponders were genotype 1
TABLE 3: comparison to values before antiviral therapy
Significant decrease in daily proteinuria in sustained virological responders
In addition, a marked increase in serum albumin levels was observed in sustained responders at the end of combination therapy and end of follow-up compared with pretreatment values
Mixed cryoglobulinemia levels at the end of tx and end of fu were decreased compared to pretreatment
Moreover, CG disappeared in 5/12 viral responders

28. Conclusion Promising but not appropriate for our patient
Anemia requiring frequent transfusions prohibits the use of Ribavirin
As per GI: ½ dose PEG-IFN
Response seen is genotype dependent:
For full dose PEG-IFN: 1b ~20% vs 2b ~40%
Interferon Alfa-2a Therapy in Cryoglobulinemia Associated with Hepatitis C Virus (Misiani, NEJM, 1994)

29. prospective randomized, controlled trial
Interferon Alfa-2a Therapy in Cryoglobulinemia Associated with Hepatitis C Virus (Misiani, NEJM, 1994)
prospective randomized, controlled trial
53 patients with HCV-associated type II cryoglobulinemia.
27 patients received recombinant interferon alfa-2a
thrice weekly at a dose of 1.5 million units for a week and then 3 million units thrice weekly for the following 23 weeks.
26 control patients did not receive anything apart from previously prescribed treatments
All patients were then followed for an additional 24 to 48 weeks.

30. Interferon Alfa-2a Therapy in Cryoglobulinemia Associated with Hepatitis C Virus (Misiani, NEJM, 1994)
Out of 27 who started, 2 stopped (Afib and depression)
After the treatment, 15 of remaining 25 had undetectable serum HCV RNA
A statistically significant and progressively increasing difference between responder and non-responder was observed from the d16th week of treatment onward
Unfortunately,
On follow up, among the 15 responders with undetectable HCV RNA (treatment for 24 weeks)
Viremia recurred within six months with accompanying clinical manifestation of cryoglobulimena
Percent Changes in the Protein Concentration of Cryoprecipitate in Patients Receiving Interferon Alfa-2a, According to Whether Viremia Persisted or Disappeared by the End of the Treatment Period

31. Peg-IFN We don’t know the genotype of responders in NEJM study
Even with response, 100% relapsed in six months

32. Treatment of HCV-related Cryoglobulinemic Glomerulonephritis
Benefit of antiviral treatment is often transient and restricted to patients with mild and/or quiescent renal disease
INF tx may be associated with worsening GN
Ribavirin may be contraindicated in the presence on renal failure and anemia
Is there no hope for our patient?

33. Rituximab? Why not?

34. Pathogenesis of Mixed Cryoglobulinemia
MC is a non-neoplastic B cell lymphoproliferative process induced by HCV in an antigen-driven mechanism
B cell activation and/or hyperproliferation with selective expansion of CG-producing B cells
the mechanisms leading to B cell expansion are still unknown
The interaction btwn HCV envelope protein E2 and the CD81 receptor on B cells may lower the activation threshold of these cells, thus facilitating the production of various autoantibodies, including IgM RF.
By itself, this process could lead to type III (polyclonal) cryoglobulinemia as monoclonal RF rarely arises in chronic human immune complex diseases.
Transformation of the IgM RF fraction from polyclonal (type III) to the oligoclonal (type II-type III variant) and then to the monoclonal (type II) may occur over a decade or more of chronic disease, and is probably the consequence of a genetic mutation.
The high prevalence of Bcl-2 rearrangement in patients with HCV-related MC is consistent with this hypothesis.
T(14;18) translocation of the Bcl-2 oncogene results in overexpression of the gene, which may prolong the lifespan of B lymphocytes, favoring the emergence of a dominant clone capable of producing monoclonal IgM-κ RF34

35. Pathogenesis of cryoglobulinaemic nephritis and rationale for Rituximab treatment
B lymphocytes are targets of HCV infection due to cell expression of the CD81 receptors, which also allow hepatocyte infection
CD81, a tetraspanin expressed on hepatocytes and B lymphocytes
Recombinant molecules containing extracellular loop of CD81 bound HCV and inhibited virus binding to CD81 in vitro
The IgM-k that has rheumatoid activity towards anti-HCV IgG forms mega-complexes that do not bind to the erythrocyte transport system,
remain free to circulate and saturate the phagocyte’s ability to remove ICs from the blood.
(impaired reticuloendothelial system removal of IgM-IgG-HCV complexes, via radiolabelled CG)
Phagocyte cell blockade is favoured by HCV infection,
which makes cells unable to digest cryoglobulins following phagocytosis.
Due to the affinity to the mesangial matrix of the monoclonal IgM component, cryoprecipitable ICs deposit in the glomeruli, where cytokine production favours leukocyte diapedesis and endothelial injury.
HOW RITUXIMAB
Rituximab is a chimeric mouse/human mAb specific for the CD20 antigen found on the surface of malignant B lymphocytes in CLL and non-Hodgkin’s lymphoma
Rituximab targets cell-surface CD20 and acts as a bridge connecting the malignant B-cells to naturally occurring immune effector cells (natural killer cells, macrophages or neutrophils).
When engaged by rituximab, the immune effector cells can kill the leukemia cells. This mechanism is called antibody-dependent cell-mediated cytotoxicity (ADCC) because, unless bridged to the tumor by rituximab, the immune effector cells are much less able to kill the tumor cells
The anti-CD20 monoclonal antibody acts at the very first step of this cascade, blocking B-cell proliferation and, thus, IgM production, which is critical for both cryoglobulin production and deposition in the glomeruli

36. Mechanism of rituximab
Why Rituximab?
Chimeric monocloanl ab
Binds to the B-cell surface Ag CD20
Stop it before it starts

37. Long-term effects of anti-CD20 monoclonal antibody treatment of cryoglobulinemic glomerulonephritis (CGGN) (Roccatello_Nephrol Dial Transplant_2004)
N = 6
Two with bone marrow lymphocyte infiltration
Four with either intolerance or resistance to standard immunosuppressive tx
HCV genotype
1b = 2
2a2c = 2
Tx:
Rituximab 375 mg/m2
days 1, 8, 15, and 22. Two additional doses were given 1 and 2 months later.
No other immunosuppressive drugs
Endpoints
Laboratory parameters
Proteinuria, ESR, cryocrit, HCV VL
Clinical sxs and symptoms
Skin ulcers, purpura, arthralgia, weakness, praesthesia and fever BM
IgM-kappa clonal restricted lymphocyte interstitial infiltration
Presence of foci of CD20 positive lymphocyte
Failed immunosuppression
Steroid (1mg/kg and cyclophosphomide 1.5mg/kg)
Glucose intolerance, leukopenia

38. Long-term effects of anti-CD20 monoclonal antibody treatment of cryoglobulinemic glomerulonephritis (CGGN) (Roccatello_Nephrol Dial Transplant_2004)
Compared with the initial values,
a significant decrease of
proteinuria
cryocrit was observed 2, 6 and 12 months after first administration of Rituximab (Figure 1).
A significant decrease for
rheumatoid factor and IgM was also observed at 6 months.
IgG levels and viral load did not change
Other study: dec in IgM, while IgA unaffected and IgG was reduced only slightly
Probably due to the lack of CD20 expression on mature plasma cells FU
Nineteen months following initiation of therapy,
patient three complained of relapsing arthralgia and worsening paraesthesia.
She had increased rheumatoid factor and dropped C4 levels.
Fourteen months after first Rituximab administration,
serum creatinine in patient 5 rose to 5.3 mg/dl without other changes in biochemical parameters

39. Long-term effects of anti-CD20 monoclonal antibody treatment of cryoglobulinemic glomerulonephritis (CGGN) (Roccatello_Nephrol Dial Transplant_2004)
Patients showed
reduction in proteinuria
Paralleled by a decrease in the ESR, RF, IgM levels and cryocrit
As well as increas in C4 levels
With no substantial changes in liver cytolytic enzymes
Moreover, no increase in VL was detected

40. No increase in VL detected
Long-term effects of anti-CD20 monoclonal antibody treatment of cryoglobulinemic glomerulonephritis (CGGN) (Roccatello_Nephrol Dial Transplant_2004)
No increase in VL detected

41. N=15, with type II MC unresponsive to conventional treatments
Efficacy and safety of rituximab in type II mixed cryoglobulinemia, Zaja, Blood, 2003
N=15, with type II MC unresponsive to conventional treatments
11/15 were HCV related
one with Sjogren syn and two were essential
F/U for 6 months
Tx: Rituximab (days 1, 8, 15, 22)
Conventional therapy:
IFN, Cyclophosphamide, plasmapheresis, IVIG, Azathiprine,

42. Efficacy and safety of rituximab in type II mixed cryoglobulinemia, Zaja, Blood, 2003
Median values
(with standard error bars)
at baseline and during the 6-month follow-up in the studied patients
A significant reduction in the serum levels of RF, cryoglobulins,and IgM was noticed after treatment, in conjunction with a significant increase in the serum levels of C4
By contrast, no significant decrease in serum IgG and IgA was noticed
For the course of ….
Changes were evaluated with respect to the baseline value in any single patient.
The course of
rheumatoid factor,
cryoglobulin, and immunoglobulin serum levels
in the studied patients after rituximab therapy

43. Conclusion
Optimal strategy for HCV-associated MC nephritis is still undefined
For our patient
INF/Ribavirin - prohibitive
INF-alpha with high relapse
Corticosteroid in combination with Rituximab