1. Tuesday Case Conference

2. Multiple Myeloma Multiple Myeloma Myeloma related renal failure
Treatment

3. Myeloma A clonal disorder of plasma cells Affects 1 in 300,000
1% of all new malignancies (16,000 per year)
10% of all new hematologic malignancies
2% of all cancer deaths (11,3000 per year)
Median age of onset: 66
Most common hematologic malignancy in African Americans
A clonal disorder of plasma cells
Affects 1 in 300,000
1% of all new malignancies (16,000 per year)
10% of all new hematologic malignancies
2% of all cancer deaths (11,3000 per year)
Median age of onset: 66
Most common hematologic malignancy in African Americans (Incidence in African-Americans is two-fold other ethnic groups)
Environmental/occupational exposures have been implicated

4. Development of Myeloma Cells
Transformation of a normal B cell into a malignant plasma cell
Environmental/occupational exposures have been implicated
Cytokines
IL-6, RANK, TNF
VEGF
Transformation of a normal B cell into a malignant plasma cell
Environmental/occupational exposures have been implicated
Higher incidence among people in agricultural occupations, petroleum workers, workes in leather industries
As well as exposure to herbicides, insecticides, petroleum products, heavy metals, plastics
Involves a multi-step process that includes genetic abnormalitis
Chromosomal changes including chromosomal translocation (generally involving the Ig heavy chain gene), and chromosomal gains and losses are very frequent in myeloma
Normally, plasma cells make up a very small portion (less than 5%) of cells in the bone marrow.
Myeloma plasma cells, however, have specific adhesion molecules on their surface allowing them to target bone marrow where they attach to structural cells called stromal cells. Once myeloma cells attach to bone marrow stromal cells, several interactions cause myeloma cells to grow (see figure):
cytokines are produced by both myeloma cells and stromal cells.
These cytokines, such as interleukin 6 (IL-6), receptor for activation of NF-κB (RANK) ligand, and tumor necrosis factor (TNF), stimulate the growth of myeloma cells and inhibit (prevent) natural cell death (called apoptosis), leading to proliferation of myeloma cells and ultimately resulting in bone destruction.
Myeloma cells also produce growth factors that promote angiogenesis, the creation of new blood vessels. These new blood vessels provide the oxygen and nutrients that promote tumor growth. A growth factor called vascular endothelial growth factor (VEGF) plays a key role in angiogenesis. Angiogenesis encourages reproduction of myeloma cells, which increase in number and begin to infiltrate the bone marrow, eventually comprising more than 10% of the cells present.
Mature myeloma cells may fail to activate the immune system and may produce substances that decrease the body's normal immune response to a foreign body. Thus, the cells can grow unchecked.

5. Multiple Myeloma - diagnosis
Clonal plasma cells >10% on bone marrow biopsy or (in any quantity) in a biopsy from other tissues (plasmacytoma)
A monoclonal protein (paraprotein) in either serum or urine
Evidence of end-organ damage
Bone marrow aspirate: Plasma cell infiltrate

6. Structure of immunoglobulin
Each light chain possesses two independent globular regions, termed constant and variable domains.
Light chains can be isotyped as kappa or lambda, based on sequences in the constant region of the protein
The variable domain forms part of the antigen-binding site of the Ig molecule and derives from rearrangement of more than 20 gene segments.
Disulfide binding among light chains with higher-molecular-weight proteins (heavy chains) occurs during or shortly after heavy chain synthesis and forms the Ig molecule that is then secreted by plasma cells.
A slight excess prodcution of light, compared to heavy, chains appears to be required for efficient Ig synthesis, but may result in release of free light chains.
Careful analysis of serum or urine from helthy individulas can reveal polyclonal light chains, albeti in very small amounts.
Light chains, particular the lambda isotype, can also form homodimers through disulfide bonding to another light chain before secretion.
Once in blood stream, light chains are handled similarly to other low-molecular-weight proteins that are removed from the circulation by the kidney.
unlike albumin, monomer (22kD) and dimers (44kD) are readily filtered through the glomerulus and reabsorbed by the proximal tubule.
In the PT, endocytosis of light chains occurs through a single class of receptors with relative selectivity for these proteins.
Megalin and cubilin
After endocytosis, lysosomal enzymes hydrolyze the proteins, and the amino acid components are returned to the circulation.
Reabsorption is saturable and allows deliver of light chains to the distal nephron and appearance in the urine as Bence Jones protein
bence jones proteins consists of immunogolbulin light chains
Plasma cells synthesize light chains that become part of the Ig molecule
Nelson DL, Cox MM. Lehninger principles of biochemistry, 4th ed. WH Freeman pub. New York 2005.

7. Serum Protein Electrophoresis
Astion ML, Rank J, Wener MH, Torvik P, Schneider JB, Killingworth LM. Electrophoresis-tutor: an image-based personal computer program that teaches clinical interpretation of protein electrophoresis patterns of serum, urine and CSF. Clin chem Sep;41(9):

8. Immunofixation Electrophoresis (IFE)
Astion ML, Rank J, Wener MH, Torvik P, Schneider JB, Killingsworth LM. Electrophoresis-tutor: an image based personal computer program that teaches clinical interpretation of protein electrophoresis patterns of serum, urine, and CSF. Clin Chem Sep;41(9):

9. Frequency of isotypes of heavy and light chains produced by non–immunoglobulin (Ig) M myelomas
Myeloma Types
Myeloma is often referred to by the particular type of immunoglobulin or light chain (kappa or lambda type)
The freq of the various immunoglobulin types of myeloma parallels the normal serum concen of the immunoglobulins.
The most common myeloma types are IgG and IgA.
IgG myeloma accounts for about 60% to 70% of all cases of myeloma and IgA accounts for about 20% of cases.
Few cases of IgD and IgE myeloma have been reported.
Although a high level of M protein in the blood is a hallmark of myeloma disease, about 15% to 20% of patients with myeloma produce incomplete immunoglobulins, containing only the light chain portion of the immunoglobulin (also known as Bence Jones proteins, after the chemist who discovered them).
These patients are said to have light chain myeloma, or Bence Jones myeloma.
In these patients, M protein is found primarily in the urine, rather than in the blood.
A more complex test called immunoelectrophoresis can measure the exact amount of Bence Jones proteins in the urine.

10. Staging and Prognostic Factors
In 1975, the Durie/Salmon staging system was developed (see Table 4).
This system brings together the major clinical parameters in correlation with measured myeloma cell mass (the total number of myeloma cells in the body).
The Durie/Salmon staging system continues to be used worldwide. However, numerous groups have proposed new systems to more accurately and simply stage and/or classify myeloma patients into prognostic categories. Thus far, no new system has gained universal acceptance.
In 2005, a new staging system was developed by the IMF-sponsored International Myeloma Working Group. Clinical and laboratory data were gathered on 10,750 previously untreated symptomatic myeloma patients from 17 institutions, including sites in North America, Europe, and Asia. Potential prognostic factors were evaluated using a variety of statistical techniques. Serum ß2 microglobulin (Sß2M), serum albumin, platelet count, serum creatinine, and age emerged as powerful predictors of survival and were then further analyzed.
A combination of serum ß2 microglobulin and serum albumin provided the simplest, most powerful, and reproducible three-stage classification. This new International Staging System (ISS) was fully validated and is shown in Table 5.
The ISS was further validated by demonstrating effectiveness in patients in North America, Europe, and Asia; in patients <and >65 years of age; with standard therapy or autotransplant; and in comparison with the Durie/Salmon system. The ISS is simple, based upon easy to use variables (serum ß2M and serum albumin), and has been introduced for widespread use.

11. Epidemiology In two large multiple myeloma studies,
43% (of 998 pts) had a creatinine > 1.5 and
22% (of 423 pts) had a Cr > 2.0
The one-year survival was
80% in pts with Cr < 1.5 compared to
50% in pts with a Cr > 2.3
5, 10, and 20 year survivals
31, 10, and 4% respectively
Prognosis is especially poor in pts who require dialysis

12. Types of renal involvement in dysproteinemias
The uncontrolled proliferation of a B-cell clone leads to overproduction of a monoclonal immunoglobulin (Ig), either an intact molecule or fragments thereof (light or heavy chains). These molecules can deposit in the kidney and other vital organs, depending on the immunoglobulin class, light or heavy chain isotype, and other only partly understood physiochemical properties. The terminology used in
these disorders is sometimes confusing and inconsistent.
We use the definitions proposed by Gallo and Kumar [73]. All diseases characterized by deposits of monoclonal immunoglobulin–related material are named monoclonal immunoglobulin
deposition diseases (MIDD).
- These deposits can occur in several forms, as outlined in the figure, and are identified by specific stains (such as congo red) and on immunofluorescence and electron microscopy. The
histologic and clinical manifestations are dependent on the type of deposition. Included in this overview are fibrillary and immunotactoid glomerulonephritis, which in certain cases also show deposits containing monoclonal immunoglobulins.
AH—heavy chain amyloidosis; AL—light chain amyloidosis; GN—glomerulonephritis; HCDD—heavy chain deposition disease; LCDD—light chain DD; LHCDD—light and heavy chain DD.

13. Pathogenesis of the different types of renal lesions in dysproteinemias
Paraproteins can deposit in the glomerular basement membrane (GBM) (and tubular basement membrane [TBM])
either as light or heavy chains, unmodified immunoglobulins, amyloids, or cryoglobulins.
Because of their size of 22 kD, light chains are freely filtered through the GBM. These light chains are then reabsorbed by proximal tubular cells.
In the PT, endocytosis of light chains occurs through a sing class of receptors with relative selectivity for these proteins (megalin and cubilin)
This process can induce a cascade of events. Because some of these light chains are relatively resistant to proteolysis, they can induce lysosomal damage. And also saturable receptors.
This damage can give rise to functional impairment of the proximal tubular cell, leading to a decreased resorptive capacity (eg, for sodium and light chains) and thereby increasing the distal delivery.
When this lysosomal overload leads to intracellular crystal formation, Fanconi’s syndrome may ensue.
Increased distal delivery of light chains can then induce precipitation of light chains together with Tamm-Horsfall protein (THP) that is secreted in the loop of Henle. Dehydration worsens cast nephropathy due to decreased flow in tubules, increased concentration of light chains
Other factors that enhance cast formation are listed in Figure This intratubular cast formation leads to obstruction, tubular damage, and an interstitial inflammatory response with leakage of THP in the interstitium, inducing macrophage influx and giant cell formation. This entity isknown as myeloma cast nephropathy.
Finally, interstitial plasma cell invasion may occur in patients with myeloma, although this rarely leads to clinical symptoms and most often is only diagnosed by kidney biopsy specimen or is seen at autopsy.
CCT—cortical collecting tubule; DT—distal tubule; LC—light chains; PCT—proximal convoluted tubule; PR—pars recta; TAL—thin ascending limb. (Adapted from Winearls [69].)

14. Myeloma Kidney Most common
Dx by demonstration of tubular casts in the distal nephron

15. Serum creatine (mg/dL)
Myeloma Kidney
Two main pathogenetic mechanisms:
Intracellular cast formation
Direct tubular toxicity by light chains
Contributing factors to presence of renal failure due to multiple myeloma:
High rate of light chain excretion (tumor load)
Concurrent volume depletion
Prognosis
Serum creatine (mg/dL)
Median survival
<1.4
44 mo
1.4-2
18 mo
>2
<4
Rayner HC, Haynes AP, Thompson JR, Russell N, Fletcher J: Perspectives in multiple myeloma: Survival, prognostic factors and disease complications in a single center between 1975 and Q J Med 79: 517–525, 1991

16. Light Chain Deposition Disease
Most commonly presents with both renal insufficiency and nephrotic syndrome
Usually due to kappa immunoglobulin fragments which deposit in kidneys (basement membrane)

17. Amyloidosis Usually due to lambda light chains (AL)
Light chains are taken up and partially metabolized by macrophages and then secreted – then precipitate to form fibrils that are Congo red positive, b-pleated
Like LCDD, due to tubular injury and also presents as nephrotic syndrome

18. Hypercalcemia
Hypercalcemia occurs in multiple myeloma due to bone resorption from lytic lesions
Serum calcium > 11.0 mg/dL occurs in 15% of pts with multiple myeloma
Hypercalcemia commonly contributes to renal failure by renal vasoconstriction, leading to intratubular calcium deposition

19. Renal Tubular Dysfunction – Acquired Fanconi syndrome
On occasion, light chains cause tubular dysfunction without renal insufficiency
Most commonly occurs with kappa light chains
This presents as Fanconi syndrome – proximal renal tubular acidosis with wasting of potassium, phosphate, uric acid, and bicarbonate

20. Fang LS. Light-chain nephropathy. Kidney Int. 1985 Mar;27(3):582-592.
Renal Insufficieny
Light chains are resistant to protease degradation and have tendency to accumulate in tubule epithelial cells and form crystals
Tubular damage due to light chain toxic effects or indirectly from the release of intracellular lysosomal enzymes
Fang LS. Light-chain nephropathy. Kidney Int Mar;27(3):

21. Presentation and outcome in myeloma-associated renal disease
Multiple Myeloma_Korbet_JASN_2006

22. Plasmapheresis in MM
Theoretical benefit in removing the toxic circulating light chains to spare renal function
Would seem to be most effective when circulating light chains in serum are present (i.e. significant M-spike on SPEP)
Limited data to support efficacy
Treatment of choice if hyperviscosity symptoms are present

23. Plasmapheresis in MM

24. Plasmapheresis studies
Johnson et al., Arch Intern Med. 1990
Forced diuresis / chemo
Plasmapheresis / diuresis / chemo N 10 11
Improvement of renal function
7/11 (64%)
5/10 (50%)
Recovery from dialysis
3/7 (43%)
0/5
Johnson et al., Arch Intern Med. 1990
Group 1: forced diuresis and chemotherapy (10 patients)
Group 2: plasmapheresis (3x/wk for 1-4 wks), diuresis, and chemo (11 patients)
7/11 pts (Group 2) and 5/10 pts (Group 1) had an improvement in renal function
3/7 pts (Group 2) and 0/5 pts (Group 1) recovered from dialysis needs
Main predictor of irreversible renal failure was degree of myeloma cast formation on renal biopsy
Concluded that plasmapheresis unlikely to be beneficial if severe cast formation, amyloidosis, or other irreversible changes are present

25. Plasmapheresis studies
Zuchelli et al., Kidney Int 1988
Plasmapheresis / chemo / HD
Chemo with PD N 15 14
Recovery from dialysis
11/13 (84%)
2/14 (14%)
One year survival
66%
28%
Zuchelli et al., Kidney Int 1988
Group 1: plasmapheresis (daily x 5 days), chemo, HD only as needed (15 pts)
Group 2: chemotherapy with PD (14 pts)
11/13 pts from Group 1 improved renal function sufficiently to stop dialysis
Only 2/14 pts from Group 2 improved renal function sufficiently to stop dialysis
One year survival: 66% in Group 1 vs. 28% in Group 2, p-value <0.01

26. Plasmapheresis studies – Limitations
Few prospective trials done
Available trials have small numbers of patients enrolled
A larger prospective, randomized trial would be beneficial in establishing the clinical utility of plasmapheresis in preventing ESRD in MM

27. Multiple Myeloma - treatment
Vincristine, doxorubicin, dexamethasone (VAD) was used for many years as pretransplantation induction therapy.86 However, VAD is no longer recommended or used as initial therapy after the introduction of several newer induction regimens.
The most common induction regimens used today are thalidomide– dexamethasone (Thal/Dex), bortezomib-based regimens, and lenalidomide–dexamethasone (Rev/Dex).
In an Eastern Cooperative Oncology Group (ECOG) randomized trial of 202 patients, the best response within 4 cycles was significantly higher with Thal/Dex compared with dexamethasone alone (63% vs 41%, respectively, P .002).
Based on this trial, in May 2006 the FDA granted accelerated approval for Thal/Dex for the treatment of newly diagnosed myeloma.

28. Treatment should be directed at ameliorating the renal lesion and reduction of the production of paraproteins.
In patients with myeloma it is very important to prevent situations that could precipitate acute renal failure. In this respect, dehydration and hypercalcemia are very harmful. Measures should be taken to maintain a high fluid intake.
When radiocontrast agents are necessary, hydration before the study decreases the chance of intratubular cast formation between light chains and the contrast agent.
Alkalization of the urine can reduce the interaction between light chains and Tamm- Horsfall protein (THP).
Nephrotoxic drugs (such as nonsteroidal anti-inflammatory drugs and gentamycin) should not be used because they further enhance tubular dysfunction.
Experimental studies suggest that colchicine may be helpful in reducing cast formation either by decreasing THP secretion or modifying the interaction between THP and light chains. Presently, no data exist that document the clinical efficacy of this treatment.
Plasmapheresis has the potential to remove the toxic light chains from the circulation, although in certain patients the serum concentration can be rather low. Plasmapheresis alone does not reduce the rate of production of the paraprotein; therefore, this treatment should be combined with chemotherapy. Patients with extensive cast formation and interstitial changes seem to respond less well to plasmapheresis that do those without cast formation and interstitial changes [81].
Of two controlled studies, only one showed a beneficial effect of addition of plasmapheresis to chemotherapy [82,83].
The major determinant for success seems to be a good response to chemotherapy [83].
Furthermore, patients with extensive cast formation and interstitial changes seem to respond less well to chemotherapy than do those without cast formation and interstitial changes [81,83].
The patient with end-stage renal disease can be treated with dialysis, although survival is poor and dependent on the success of chemotherapy.
The experience of renal transplantation in patients with dysproteinemias is, for obvious reasons, rather limited. The results are rather disappointing with a high mortality rate, especially in patients with multiple myeloma and amyloidosis. Patients surviving for more than 1 year show a high recurrence rate [84–87].
Discussion of antitumor therapy is beyond the scope of this review.
Briefly, treatment with melphalan and prednisone is considered to be the first choice, whereas more aggressive treatment with vincristine-adriamycin-dexamethasone is given to patients who do not respond to or who relapse after melphalan and prednisone therapy.
Recently, more encouraging results have been obtained with ablative chemotherapy and stem-cell reinfusion [88].
PD—peritoneal dialysis.

29. Novel Therapies Velcade (bortezomib) Revamid Proteasome inhibitor
Induces apoptosis via caspase-8, 9
Anti-myeloma effects by blocking NF-kB
Revamid
IMiD
Induce G1 growth arrest
The proteasome is an enzyme complex that exists in all cells and plays an important role in degrading proteins involved in the cell cycle, growth of new blood vessels (angiogenesis), cell adhesion, cytokine production, apoptosis, and other important cellular processes.
Proteins are tagged for degradation by small proteins called ubiquitin leading to degradation by proteasome
Caspase – cysteine proteases
Inhibits protesome activity
Induces apotposis via caspase-8,9
Donwregulate adhesion molecules and binding of MM cells and MMStromal Cells
Blocks constitutive and adhesion-induced NFkb dependent cytokine secretion in BMSCs
Inhibits angiogenesis
Velcade is the first in a class of medicines called proteasome inhibitors and was the first treatment in more than a decade to be approved for patients with multiple myeloma in It received full approval for use in patients who have received one prior therapy in 2005.
Details on Velcade's Mechanism of Action
Many of the processes that rely on proteasome function can contribute to the growth and survival of cancer cells. Velcade is a potent but reversible inhibitor of the proteasome. By disrupting normal cellular processes, proteasome inhibition promotes apoptosis. Non-clinical data has demonstrated that cancer cells are more susceptible to the effects of proteasome inhibition than normal cells. Due to the reversibility of proteasome inhibition with Velcade, normal cells can recover from its effects, whereas cancer cells are more likely to undergo apoptosis.
NF-kB
Transcription factor, which responds to external stimuli to cause cell growth.
Also increase expression of adhesion molecules
Factors promote growth: IL-6 and VEGF (vascular endothelial growth factor)
For the 121 patients achieving a response (CR or PR) on the VELCADE arm, the median duration was 8.0 months (95% CI: 6.9, 11.5 months) compared to 5.6 months (95% CI: 4.8, 9.2 months) for the 56 responders on the dexamethasone arm. The response rate was significantly higher on the VELCADE arm regardless of β2-microglobulin levels at baseline.

30. Ubiquitin-conjugation (at left) and ubiquitin-proteasome (right) pathways.  
Protein substrates (red) destined for degradation by the proteasome are conjugated by a ubiquitin-chain "tag" (orange).
The conjugation, or ubiquitylation, process is a tightly regulated, ATP-dependent three-step enzymatic cascade.
Polyubiquitylated proteins are subsequently identified by the 26S proteasome and degraded.
Specific deubiquitylating enzymes (DUBs) cleave the ubiquitin chain from the substrate protein.
Other DUBs may further process the chain into ubiquitin monomers for recycling.
While the ubiquitin-proteasome pathway comprises the major non-lyso-somal proteolytic pathway in eukaryotes, ubiquitylation has other important roles. Depending on the number of ubiquitin moieties and the linkages made, ubiquitin also plays a role in DNA repair, protein sorting and virus budding.

32. Revlimid (lenalidomide)
First of new class of drugs called IMiDs

33. Alkylating agents, Bortemozid, corticosteroids inhibit cell growth and induce apoptosis
Bortemozid inhibits NF-kB
Thalidomide and Bortemozid inhibit interaction between myeloma cells & stromal cells as well as cytokine production (TNF-alpha, IL-6)
Thalidomide inhibits angiogenesis and enhances CD8+ and NK cell functions

34. Incidence of renal involvement in dysproteinemias
This incidence is not identical for all paraproteinemias. The reason is directly related to the frequency and degree of light chain proteinuria [71].
Ig—immunoglobulin. (From Pruzanski [72]; with permission.)

35. Causes of renal failure in MM
Cast nephropathy
Light chain deposition disease
Primary amyloidosis
Hypercalcemia
Renal tubular dysfunction
Volume depletion
IV contrast dye, nephrotoxic meds

36. Treatment of renal failure in MM
Hydration with IV fluids
Treatment of hypercalcemia
Loop diuretics
Caution with bisphosphonates
Treatment of myeloma
Pulse steroids +/- thalidomide
VAD chemotherapy
Possible role for plasmapheresis
Dialysis, as necessary

37. Multiple Myeloma - treatment
Arsenic trioxide
Thalidomide +/- Melphalan
Cyclosporin A nonimmunosuppresive analogs
Anti-IL-6 and anti-IL-6R antibodies
Bortezomid (Velcade)
Proteasome inhibitor
Bone marrow transplantation