Norimasa Yasuda

Selective IgA deficiency in Japanese blood donors: frequency and statistical analysis.

Abstract. The incidence of selective IgA deficiency (SIgAD) was determined in a healthy adult population of 222,597 Japanese volunteer blood donors. Of the blood donors screened, only 0.007% (1:14,840) were found to be IgA‐deficient (less than 10 mg/dl) by means of the double diffusion method, while 0.005% (1:18,500) were less than 5 mg/dl, and 0.003% (1:31,800) were less than 1 mg/dl by means of the single radial immunodiffusion method. Statistical analysis of the results clearly showed that the incidence of SIgAD in Japanese blood donors is very much lower than that in blood donors of European ancestry. The Japanese population may occupy a unique position in the ethnical peculiarities. Anti‐IgA antibodies were found in 3 (25.0%) of 12 IgA‐deficient blood donors whose IgA levels were less than 5 mg/dl, a prevalence rate comparable to that in donors of European ancestry. Although it is difficult to develop a suitable file of IgA‐deficient donors in Japan, the establishment of a Rare Donor Registry System on IgA deficiency is a matter of urgency.

Ultrastructure of vacuolated plasma cells in macroglobulinemia associated with production of Mu-chain fragment

In a unique case of macroglobulinemia associated with the production of mu‐chain fragment, the authors observed vacuolated plasma cells (Vac‐P) in the bone marrow. Immunofluorescence with anti‐mu‐chain showed positive staining for the cytoplasm but negative for the vacuoles. On electron microscopic study, clear vacuoles were localized in the vicinity of the Golgi complex, and the contents were amorphous membrane debris and concentric circular structures. The vacuolar membrane was partially disrupted and was contiguous with the outer surface of the concentric circular structure. From the findings, the authors thought these vacuoles were autophagic. Disruption of vacuolar membranes was also demonstrated in three other cases of Vac‐P studied with electron microscope. Heterophagy of toxic substances, such as silica or salt or urate, leads to membrane disruption. Vac‐P observed in abnormal mu‐chain production may produce toxic substances. Once the substance is incorporated into the autophagic vacuole, the vacuolar membrane will be weakened, and the absorption of part of the membrane and cytoplasm or organelles follows.

Vacuolated plasma cell: ultrastructural distribution of acid-phosphatase and intracellular immunoglobulin

In two cases of vacuolated plasma cells, one of which was associated with primary macroglobulinemia and the other was with kappa-chain Bence Jones multiple myeloma, we examined the immunopathological features of the vacuoles in order to know whether the Ig-secreting system or the lysosomal system is of importance in the process of vacuole formation. Immunofluorescent studies detected no Ig in the vacuoles. Detection of intracellular Ig by immunoelectron microscopic technique revealed that Ig was localized only in a small portion of the vacuoles but not in most vacuoles. Even when Ig was included in the vacuoles, only the contents of the vacuoles were positive for Ig but their demarcating membrane was negative for Ig. In contrast, electron microscopic studies of acid phosphatase activity revealed the presence of its activity in all vacuoles. These findings suggest that the lysosomal system but not the Ig-secreting system may play a major role in vacuolation of these myeloma cells.

Intracellular immunoglobulin in lymphocytes from patients with chronic lymphocytic leukemia: An immunoelectron microscopic study

The presence of ultrastructural distribution of intracellular immunoglobulin (Ig) in leukemic cells from patients with chronic lymphocytic leukemia (CLL) and in normal B cells were investigated by an immunoelectron microscopic technique. Most normal B cells had no intracellular Ig in spite of the presence of surface Ig. However, leukemic cells from 10 to 11 patients with CLL contained intracellular Ig and showed various staining patterns. In eight patients, Ig was present in the perinuclear space (PN), the endoplasmic reticulum (ER) and, if identified, the Golgi complexes. In four patients, most cells had diffuse staining of the cytoplasm. In five patients, Ig was detected in the ER-associated structures or the vesicles, in addition to the PN and ER. These findings suggest that CLL cells have a greater capacity to produce Ig than those of normal B cells and include various clones with distinct staining patterns of intracellular Ig.

Nucleolus-associated J chains in myeloma cells: Clinical significance

Bone marrow aspirates from 20 patients with multiple myeloma (MM), 4 with smoldering multiple myeloma (S‐MM), 1 with idiopathic Bence Jones proteinuria (I‐BJP), and 6 with primary macroglobulinemia (PMG) were examined for nucleolus‐associated J chain. The incidence of nucleolar J chain‐positive (J +) cells among nucleolated cells producing M‐component was measured. This incidence (94.0–100%) in terminal MM was significantly higher than that (0–58.0%) in non‐terminal MM. Judging from a low incidence in the remission phase, chemotherapy might cause a selective elimination of less differentiated myeloma cells with J + nucleoli and might have some effect on J chain synthesis. The incidence of nucleolar J+ cells was very low in S‐MM. The IgM cells in PMG, where J chain is present in a disulfide‐linked form, had no or few J+ nucleoli. No correlation between the incidence of nucleolar J + cells among nucleolated plasma cells and the percentage of nucleolated cells or that of J + cells was found. Large J + nucleoli seemed to be another morphological feature indicating anaplastic myeloma cells. A high incidence of nucleolar J + cells may be one of the indicators for progressive disease.