s e c t io n v i.

1

Serum Protein Electrophoresis

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FIGURE VI-3

Serum immunofixation electrophoresis of two patients with monoclonal gammopathies. Pattern A represents IgG(/tr)

monoclonal gammopathy and pattern B represents IgA(/c) monoclonal gammopathy, as indicated by arrows. The

procedure consists of serum protein electrophoresis (SPE) separation, reaction of each track with the exception of SPE

with specific respective antiserum, followed by protein staining to make visible the respective bands.

presence of a homogeneous class of protein (Figures

VI- lc and VI-2). Such a pattern should be further

investigated using other laboratory and clinical

findings to rule out multiple myeloma.

Means of investigation include quantitation of im-

munoglobins, immunofixation electrophoresis to iden-

tify the class and type of monoclonal immunoglobulin

(Figure VI-3), bone marrow aspiration and biopsy to deter-

mine plasmacytosis, and radiological examination to iden-

tify osteolytic lesions. Multiple myeloma is a disorder of

neoplastic proliferation of a single clone of plasma cells in

the bone marrow that leads to overproduction of any one of

the five immunoglobulins (IgG, IgA, IgM, IgD, or IgE) or

light chains

(k

or A). Less commonly, biclonal or triclonal

gammopathy also occurs. If the light chains are overpro-

duced, they pass through the glomeruli and appear in the

urine; this is known as

Bence Jones proteinuria.

In a given

individual, Bence Jones proteinuria refers to either

a:

or A

.

light chains but not both. Persons over age forty may be

affected and the initial findings may include spontaneous

fractures, bone pain, anemia, or infections. Hypercalcemia

may be found after bone destruction. Multiple myeloma is

a progressive disorder and is usually fatal due to renal dam-

age and/or recurrent infections. Cytotoxic measures (e.g.,

melphalan, a nitrogen mustard) are used in the treatment

of multiple myeloma, and serum and/or urine monoclonal

immunoglobulin or light chain levels serve in monitoring

therapy.

Although the monoclonal spike is usually observed in

the

ß-y

region, it is occasionally seen in the

012

region. In

pregnancy, a monoclonal spike in the

ß

region may be due

to elevated transferrin levels. A serum electrophoretic pat-

tern of hypogammaglobulinemia requires further studies

of serum and urine (e.g., immunoglobulin measurement

and immunofixation electrophoresis) to rule out multiple

myeloma. The presence of monoclonal immunoglobu-

lin in the serum is a characteristic feature of a majority