Distribution of immunoglobulin-containing cells in bone marrow and lymphoid tissues in patients with monoclonal gammapathy

Differentiation of plasma cell infiltrates in the bone marrow. A clinicopathological study on 80 patients including immunohistochemistry and morphometry

In 80 patients immunohistochemical, morphometrical and clinical studies were performed on routinely referred trephine biopsies of the bone marrow showing an abnormal increase in plasma cells. From the approximately determined density of plasma cell infiltrates two main groups were distinguished, the first with an involvement exceeding 20% and the second with less than 10% of the total marrow area involved. The first group (n = 30; 324 +/- 130 plasma cells per square millimeter bone marrow) consisted of patients with frank malignant myeloma (MM) by clinical and histomorphological diagnosis. The second group (n = 50; 132 +/- 54 plasma cells per square millimeter bone marrow) with plasmacytic differentiation of infiltrates, had to be further divided into one component with evidence for initial or residual MM following chemotherapy (n = 27), another with obviously monoclonal gammopathy of undetermined significance--benign monoclonal gammopathy (BMG, n = 6), and a final set of cases with a reactive plasmacytosis mostly associated with an inflammatory condition (n = 17). There was an excellent agreement between the intracellular immunoglobulin staining as defined by the immunoperoxidase technique and the serum or urinary M-component detected by immunoelectrophoresis. In MM significant correlations were found between osteoclastic activity (number of osteoclasts specifically stained by acid phosphatase) per trabecular bone area, presence of lytic bone defects and the density of plasma cell infiltrates in the marrow. This latter feature corresponded well with the titer of secreted serum M-components measured by quantitative immunoelectrophoresis. Using morphological data alone, BMG cases could not be discriminated with any certainty from initial or residual plasmacytic MM. They consequently need a prolonged clinical follow up to clarify the nature of the lesions.

Bone-marrow plasmocytosis--an immunohistological study

Bone-marrow biopsies and smears from 59 patients with reactive plasmocytosis (22), multiple myeloma (24), solitary plasmocytoma (3) and monoclonal gammopathy of undetermined significance (MGUS) (10) were examined. To demonstrate cytoplasmic immunoglobulin the immunoperoxidase method was applied and evaluated quantitatively. Immunohistology yielded different ranges in kappa/lambda ratio for reactive plasmocytosis (0.4-3.5), multiple myeloma (less than or equal to 0.1 and greater than or equal to 11.2) and MGUS (0.2-3.0). As a result this method seems to be helpful in characterizing a plasmocytosis and distinguishing overt myeloma from monoclonal gammopathy of undetermined significance and reactive plasmocytosis. A differentiation of monoclonal gammopathy of undetermined significance from reactive plasmocytosis is not possible histologically and immunohistologically.

Abnormal function of B lymphocytes from peripheral blood of multiple myeloma patients. Lack of correlation between the number of cells potentially able to secrete immunoglobulin M and serum immunoglobulin M levels

Multiple myeloma patients are deficient in normal polyclonal serum immunoglobulins. To determine the reasons for this decrease, we quantitated and compared the number of surface IgM+ B lymphocytes, and the number of B cells susceptible to transformation by Epstein-Barr virus (EBV) with the concentration of IgM in serum. Serum IgM levels varied considerably in individual patients, temporally shifting from undetectable to normal amounts and then dropping again to undetectable levels. A transient rise to normal serum IgM concentrations was seen in 42% of patients assessed at two or more time points. Of 44 patients, 52% showed a lack of correlation between the number of surface IgM+ (sIgM+) B cells and serum IgM concentration. One subset of patients (25%) had detectable to normal numbers of sIgM+ B cells in blood but undetectable levels of serum IgM. Transformation of B cells from these patients indicated a block in IgM secretion that was extrinsic to the B cells that were fully able to transcribe, translate, and secrete IgM after EBV transformation. A second subset of patients (27%) had undetectable numbers of sIgM+ B cells but near normal levels of serum IgM, suggesting abundant secretion by few clones of B cells. Of 18 patients with monoclonal gammopathy of undetermined significance (MGUS), 26% showed a lack of correlation between the numbers of sIgM+ B cells and serum IgM concentration. We suggest that in patients with multiple myeloma, and in some with MGUS, there exists a mechanism(s) extrinsic to the B cell that mediates an arrest in terminal B lymphocyte maturation.

Polyclonal plasma cell proliferation with systemic capillary hemangiomatosis, endocrine disturbance, and peripheral neuropathy

An autopsy case of so-called plasma cell dyscrasia (PCD) of a 37-year-old woman was reported. This case showed typical clinical symptoms of PCD, except for no abnormality in serum immunoglobulins. Besides the typical histological findings often observed with PCD, the autopsy revealed an additional finding of systemic angiomatous proliferation of small blood vessels throughout the body, especially in the skin, kidneys, brain, various lymph nodes, and soft tissue. A peculiar glomerular lesion in this case, similar to membranoproliferative glomerulonephritis, was likely to be a result of proliferation of glomerular capillaries. In addition, this case showed histological evidence of retroperitoneal fibrosis and osteosclerosis. These findings were also considered to be due to the vascular abnormality. Although the etiology of the vascular lesions is obscure, it is emphasized that the abnormality is probably an important cause of the clinical symptoms seen in PCD.

Intracellular immunoglobulin distribution of bone marrow plasma cells as a diagnostic aid for primary amyloidosis

In order to classify the underlying disorder in four patients with biopsy-proven amyloidosis without overt monoclonal gammopathy, the cytoplasmic immunoglobulin (Ig) distribution of bone marrow plasma cells was evaluated using direct immunofluorescence microscopy. This procedure revealed the presence of a monoclonal proliferation of light chain containing plasma cells, and thus led to the diagnosis of immunoglobulin-related amyloidosis.

Lymphomas and pseudolymphomas of the alimentary tract. An immunohistochemical study with clinicopathologic correlations

One hundred one lymphoproliferative lesions of the gastrointestinal tract (66 malignant lymphomas, 20 pseudolymphomas, and 5 borderline lesions) were reviewed. The pathologic features were compared to the clinical findings, with reference to differential diagnosis and prognosis. Special attention was paid to immunohistochemical features. The gross appearance was diagnostic in only a limited number of cases. Endoscopic biopsy alone was also of limited value because only a diagnosis of probability could be made in several cases. In most of them the definitive diagnosis had to be based on histologic examination of the resected specimen. Immunohistochemical examination was found to be very useful as an ancillary diagnostic technique. Malignant lymphomas displayed either cytoplasmic immunoglobulins with a monoclonal pattern (47.1 per cent) or a negative reaction, whereas the pseudolymphomas were generally characterized by polyclonal immunoglobulins. Ninety per cent of malignant lymphomas with cytoplasmic immunoglobulins contained lambda chains. The survival probability was found to be related to the size of the lesion, the depth of infiltration, and the immunohistochemical characteristics of the tumors. The histologic type of the lymphomas was of limited value as a predictor of prognosis in the present series.

T lymphocyte subpopulations in the bone marrow and peripheral blood of untreated patients with myeloma

The quantitative distribution of the two main T lymphocyte subsets, recognizable by the 'high' and "low-affinity' E rosette-forming cell technique of West, was studied in both the bone marrow and peripheral blood from ten untreated multiple myeloma (MM) patients. A reduced total T lymphocyte count, with a relative predominance of 'low-affinity' T lymphocytes (putative suppressor T cells), was found in the peripheral blood. Within a normal total T lymphoid cell count, a predominance of the T lymphocyte subset with 'low-affinity' characteristics was also observed in the bone marrow. An inverse correlation, that was statistically significant, was seen between the monoclonal malignant cellular B component and the 'low-affinity' T cell percentage in all cases. It is concluded, therefore, that such an imbalance between the 'high' and "low-affinity' T subsets, with the latter predominating, could be of importance in the regulation of the growth rate of the monoclonal cellular B component.

Enzymecytochemistry and immunohistochemistry in monoclonal gammopathy and reactive plasmacytosis

Peripheral blood smears and bone-marrow smears from 29 patients with malignant M-components (25 with multiple myeloma and 4 with malignant lymphoma), 13 patients with benign monoclonal gammopathy (BMG), and 20 patients with polyclonal reactive plasmacytosis were examined by leucocyte alkaline phosphatase score (LAP-score) and by acid phosphatase score in plasma cells from bone-marrow smears. Furthermore, tissue sections from marrow biopsies from all patients were examined by the three-layer unlabelled immunoperoxidase technique to detect cytoplasmic immunoglobulin. The LAP-score was significantly higher in patients with malignant M-components than in patients with BMG and also higher in IgA and IgG myeloma than in IgA and IgG BMG, but the latter difference was not significant. Furthermore, a significant positive correlation between paraprotein concentration and LAP-score was found in multiple myeloma. Acid phosphatase score in plasma cells showed no clear distinction between multiple myeloma and BMG. Immunohistochemical examination showed a distinct monoclonal pattern in both multiple myeloma and BMG, allowing identification of the M-component which in all cases corresponded to the M-component detected by serum examination. Cells producing immunoglobulin classes not matching the M-component were more rare in multiple myeloma than in BMG, but the difference between the two conditions was quantitative and allowed no clear distinction.