Monoclonal immunoglobulin is elevated, don't just think of MM

Preamble

Plasma cell tumors are tumors
formed by the proliferation of B cells at the end of differentiation that secrete clonal immunoglobulins and have heavy chain switching.
It secretes paraproteins or M-proteins, which are monologous (monoclonal) immunoglobulins
.

Case history

Case 1:

The patient is an elderly man who is found to be anemia for more than 2 months and is accompanied by fatigue
.
Blood routine shows anemia and thrombocytopenia
.
Microscopic examination shows 1% of neutrophils and red blood cells arranged in a money-like manner
.

Coagulation results

Biochemical showed an increase in total protein (91.
1 g/L) and an increase in globulin (56.
3 g/L).

Serum immunoglobulin M increased (>32.
0 g/L), serum immunoglobulin A decreased (<0.
38 g/L)

M protein bands were found by serum protein electrophoresis, and the M protein content was 30.
84 g/L

Serum immunofixation electrophoresis showed that the monoclonal immunoglobulin type was IgM-λ.

Urinalysis is weakly positive
for urine protein.

M protein bands were found by urine protein electrophoresis, and the M protein content was 216.
48mg/24h

Urine is positive for protein this week, and the type is lambda free light chain

Combined with the above items: abnormal monoclonal bands were found in serum protein electrophoresis, and the M protein content was 30.
84g/L
.
The serological fixed electrophoresis is classified as IgM-λ.

Urine electrophoresis found abnormal monoclonal bands, M protein content of 216.
48mg/24h, type λ free light chain type
.

Case 2:

The patient is an elderly man who has no obvious cause of weakness in the lower limbs before half a month, and worsens after activity, and is found to have severe anemia on local examination
.
Review the progressive decline in
hemoglobin on the blood routine.

Increased ESR:

Normal folic acid, vitamin B12:

Biochemical and hemagglutination results:

Serum immunoglobulin G increased (24.
1g/L), serum immunoglobulin A and immunoglobulin M decreased
.

Serum protein electrophoresis found M protein bands with M protein content of 7.
45g/L

Serum immunofixation electrophoresis showed that the monoclonal immunoglobulin type was IgG-κ
.

Urinalysis is negative
for urine protein.

Urine protein electrophoresis did not reveal M protein

Urine is protein-negative

Combined with the above items: abnormal monoclonal bands were found in serum protein electrophoresis, the M protein content was 7.
45g/L, and the serum immunofixation electrophoresis was IgG-κ type
.
Urine electrophoresis did not detect abnormal monoclonal bands
.

Case studies

Case 1:

Patients with anemia, normocytic normochromic anemia, high globulin, high IgM, monoclonal, combined with old age, red blood cells are arranged in a money-like manner, plasma cell diseases
should be excluded.
Examination of the body is soft, the spleen has three transverse fingers under the ribs, and there is no tenderness and rebound tenderness
.
The patient has an enlarged spleen, 1% of peripheral blood naïve cells, and the condition is more complicated, and bone marrow puncture examination
should be improved.

Bone marrow was sent for examination, hyperplasia was active, the proportion of mature lymphocytes increased significantly, accounting for 77%, the three lines were reduced, and the mature red blood cells were arranged in a money-like manner:

Flow cytometry showed 71.
6% CD5 negative, CD10 positive a small number of monoclonal small B lymphocytes, no obvious plasma cells
detected.

Biopsy is consistent with B-cell chronic lymphoproliferative disease and does not exclude lymphoplasmacytic lymphoma
.

Karyotyping:

Considered as a chronic B-lymphocyte proliferative disorder, CD5 negative can exclude CD5-positive chronic lymphoid and mantle cell lymphoma
.
Bone marrow pathological lymphoma-related immunohistochemistry and lymphoma second-generation sequencing MYD88 examination should continue to be
improved.

Case 2:

Examination of weight anemia, superficial lymph nodes are not palpated, and the liver and spleen are not palpable
.
Peripheral blood is macrocytic anemia, folic acid and vitamin B12 are normal, IgG is elevated, it is monoclonal, and it is highly suspected of multiple myeloma
.
Bone marrow aspiration should be performed
.

Bone marrow for examination: hyperplasia is active, the proportion of mature lymphocytes is significantly increased, accounting for 93.
5%, and the three lineages are reduced:

Flow cytometry showed 63.
2% CD5-negative CD10-negative monoclonal B lymphocytes, and no obvious plasma cells
were detected.

Biopsy considers B-cell lymphoma
.

Karyotyping:

Considering the proliferation of B lymphocyte diseases, the second-generation sequencing of lymphoma MYD88 gene mutation examination should continue to be improved to rule out the possibility of
lymphatic plasma cell lymphoma.

Case summary

The presence of M protein can be divided into primary and secondary conditions
.

Primary: M protein as a plasma cell product can occur in any proliferative disorder
with plasma cells or B lymphocytes.
Such as: MM, LPL/WM, B-cell lymphoma, leukemia, etc
.

Secondary: a variety of primary diseases can also cause clonal plasma cell proliferation
.
Such as: MGUS, connective tissue disease, kidney disease and benign and malignant tumors
.

【References】

[1] Clinical Hematology Testing/Xu Wenrong Wang Jianzhong, ed.
5th ed.
Beijing: People's Medical Publishing House, 2012

[2] Clinical Laboratory Diagnostic Atlas/edited by Wang Jianzhong.
Beijing: People's Medical Publishing House, 2012

[3] Criteria for diagnosis and efficacy of blood diseases/Shen Ti Zhao Yongqiang, editor.
4th ed.
Beijing: People's Medical Publishing House, 2018

[4] Hematology/Zhang Zhinan, Hao Yushu, editor-in-chief.
2nd ed.
Beijing: People's Medical Publishing House, 2011