Age-related change of distribution of immunoglobulin containing cells in human bone marrow. Changes in patients with benign monoclonal gammopathy and multiple myeloma

Analysis of Normal Plasma Cell Distribution Across Distinct Age Cohorts Reveals Age-Dependent Changes

Hematopoietic and stromal cells within the bone marrow (BM) provide membrane-bound and/or soluble factors that are vital for the survival of plasma cells (PCs). Recent reports in murine BM demonstrated the dynamic formation and dispersion of PC clusters. To date, PC clustering in normal human BM has yet to be thoroughly examined. The goal of this study was to determine whether PC clusters are present in human BM and whether clustering changes as a function of age. Quantification of PCs and clustering in BM sections across six different age groups revealed that fewer PCs and PC clusters were observed in the youngest and oldest age groups. PC clustering increased with age until the sixth decade and then began to decrease. A positive correlation between the number of PCs and PC clusters was observed across all age groups. PC clusters were typically heterogeneous for immunoglobulin heavy- and light-chain expression. Taken together, these data demonstrate that PC clusters are present in human BM and that PC clustering increases until middle adulthood and then begins to diminish. These results suggest the spatial distribution of BM PC-supportive stromal cells changes with age.

Gender dimorphism in IgA subclasses in T2-high asthma

Immunoglobulin A (Chan in J Allergy Clin Immunol 134:1394-14014e4, 2014), the second most abundant immunoglobulin in serum, plays an important role in mucosal homeostasis. In human serum, there are two subclasses of IgA, IgA1 (≅ 90%) and IgA2 (≅ 10%), transcribed from two distinct heavy chain constant regions. This study evaluated the serum concentrations of total IgA, IgA1, and IgA2, and total IgG, IgG1, IgG2, IgG3, and IgG4 in T2-high asthmatics compared to healthy controls and the presence of gender-related variations of immunoglobulins. Total IgA levels were increased in asthmatics compared to controls. Even more marked was the increase in total IgA in male asthmatics compared to healthy male donors. IgA1 were increased only in male, but not in female asthmatics, compared to controls. Concentrations of IgG2, but not IgG1, IgG3, and IgG4, were reduced in asthmatics compared to controls. IgG4 levels were reduced in female compared to male asthmatics. In female asthmatics, IgA and IgA1 levels were increased in postmenopause compared to premenopause. IgA concentrations were augmented in mild, but not severe asthmatics. A positive correlation was found between IgA levels and the age of patients and an inverse correlation between serum concentrations of IgA2 and IgE in asthmatics. A positive correlation between total IgA or IgA2 and IgG2 was found in asthmatics. These results highlight a gender dimorphism in IgA subclasses in male and female T2-high asthmatics. More adequate consideration of immunological gender disparity in asthma may open new opportunities in personalized medicine by optimizing diagnosis and targeted therapy.

Slower immune system aging in women versus men in the Japanese population

BACKGROUND

Gender-related differences in humans are commonly observed in behaviour, physical activity, disease, and lifespan. However, the notion that age-related changes in the immune system differ between men and women remains controversial. To elucidate the relationship between immunological changes and lifespan, peripheral blood mononuclear cells from healthy Japanese subjects (age range: 20-90 years; N = 356) were analysed by using three-colour flow cytometry. The proliferative activities and cytokine-producing capacities of T cells in response to anti-CD3 monoclonal antibody stimulation were also assessed.

RESULTS

An age-related decline in the number of T cells, certain subpopulations of T cells (including CD8+ T cells, CD4+CDRA+ T cells, and CD8+CD28+ T cells), and B cells, and in the proliferative capacity of T cells was noted. The rate of decline in these immunological parameters, except for the number of CD8+ T cells, was greater in men than in women (p < 0.05). We observed an age-related increase or increasing trend in the number of CD4+ T cells, CD4+CDRO+ T cells, and natural killer (CD56+CD16+) cells, as well as in the CD4+ T cell/CD8+ T cell ratio. The rate of increase of these immunological parameters was greater in women than in men (p < 0.05). T cell proliferation index (TCPI) was calculated from the T cell proliferative activity and the number of T cells; it showed an age-related decline that was greater in men than in women (p < 0.05). T cell immune score, which was calculated using 5 T cell parameters, also showed an age-related decline that was greater in men than in women (p < 0.05). Moreover, a trend of age-related decreases was observed in IFNγ, IL-2, IL-6, and IL-10 production, when lymphocytes were cultured with anti-CD3 monoclonal antibody stimulation. The rate of decline in IL-6 and IL-10 production was greater in men than in women (p < 0.05).

CONCLUSION

Age-related changes in various immunological parameters differ between men and women. Our findings indicate that the slower rate of decline in these immunological parameters in women than that in men is consistent with the fact that women live longer than do men.

Age-related changes of human bone marrow: a histometric estimation of proliferative cells, apoptotic cells, T cells, B cells and macrophages

We performed an immunohistological study using biopsy samples of bone marrow obtained from patients, ranging in age from a newborn baby to 100 years old. Those patients suffering from hematological diseases or diseases that would be capable of affecting hematopoiesis were not included in the present study. The cellularity of the bone marrow did not change significantly with age during the first and the eighth decades, while the oldest group, ranging in age from 80 to 100, revealed significantly low cellularity. Proliferative activity assessed by Ki-67-positive cells was high in the middle-aged group and declined slightly in the elderly group. It was of interest to note that the percentage of apoptosis was relatively low in the young and middle-aged group, but significantly increased in the elderly group. The percentage of T cells did not change greatly between the first and the fifth decades, peaked at the sixth decade and gradually decreased thereafter. The percentage of B cells was about 10% at the first decade, decreased thereafter until the third decade, then increased again showing a peak at the sixth decade, and decreased thereafter. The percentage of CD68-positive cells was high in young patients, and decreased in the adult and elderly patients. The data in the present study suggest that hypocellularity in the bone marrow of elderly people could be ascribed partly to the increase of apoptosis, and might possibly be related to a decrease in the number of lymphocytes and macrophages, which would constitute part of the bone marrow microenvironment supporting hematopoiesis.

Humoral immunity in aging

The interactions between B and T lymphocytes, leading to the development of humoral responses, are reviewed with references to the changes occurring in aged people. Aging is perceived as a process of impairment of immune functions; it is known that T cells from aged subjects have a reduced ability to produce IL-2. However, other functions seem to be upregulated in elderly subjects; indeed, IL-1, IL-3, IL-4, IL-6 and TNF alpha production are increased both in aged mice and humans. These cytokines are known to control B cell differentiation, through isotype switch and Ig production. A significant increase in IgG subclasses and IgA is observed in sera of aged subjects. This contrasts with the significant decrease in circulating B lymphocytes. The impairment of primary responses to immunization, and other aspects of humoral immunity, including mucosal responses, autoantibody production and correlations with phenotypic markers of T and B cell subsets, are discussed.

A comparative study of monoclonal gammopathies and immunoglobulin levels in Japanese and United States elderly

OBJECTIVE

To define the prevalence of monoclonal immunoglobulin (Ig) proteins and quantitative serum immunoglobulin levels in elderly Japanese in comparison with elderly Caucasians as possible factors related to the reported lower incidence of multiple myeloma in elderly Japanese than in elderly Caucasians.

DESIGN

Survey study

SETTING

Community Center in Yokohama, Japan and Retirement Community in the United States.

PARTICIPANTS

Convenience sample of community-dwelling elderly subjects (age 63-95) presenting for health screening examinations in each setting. Frozen serum samples were obtained from routine screening from 146 consecutive Japanese subjects and 111 US subjects.

INTERVENTION

None

MEASUREMENTS

Presence of monoclonal immunoglobulin protein determined by serum protein electrophoresis and immunofixation and quantitative Ig by laser nephelometry.

RESULTS

Four (2.7%) of the Japanese cohort had monoclonal gammopathies compared with 11 (10%) of the American cohort. Two of the monoclonal gammopathies were IgG Kappa and two were IgG Lambda. No cases of multiple monoclonal gammopathy were identified in the Japanese group, compared with 25% of the monoclonal gammopathies in the American group. The mean quantitative serum IgG level for the Japanese group was 1,685 +/- 520 mg/dL versus 1,118 +/- 402 mg/dL for the American group; mean quantitative IgA levels were 283 +/- 116 mg/dL versus 226 +/- 116 mg/dL (P < 0.001). Albumin levels were normal in both populations, suggesting that there was not an increase in occult inflammatory disorders in the Japanese population.

CONCLUSION

The low prevalence of monoclonal gammopathy in elderly Japanese is consistent with the reported lower frequency of multiple myeloma. The reason for the higher quantitative immunoglobulin levels in this population is unclear. Further cross-cultural investigation is warranted to explore the genetic influences on altered immune regulation with aging.

Aging and immunity

The function of the immune system peaks at around puberty and gradually declines thereafter with advance in age. The age-related decline of immunological function primarily occurs in the T cell-dependent immune system and is generally associated with increase in susceptibility to infections as well as in incidence of autoimmune phenomena in the elderly. The age-related change in T cell-dependent immune functions can be ascribed to the physiological thymic atrophy which starts in an early stage of life. Emigration of T cells from the thymus to the periphery mainly takes place in the late fetal and newborn stage, and dramatically declines after puberty. In other words, the thymic capacity to promote T cell differentiation starts to change in the early stage of life in terms of quantity and quality of T cells. Thus, the composition of T cell-subsets in the periphery gradually changes with age, resulting in the alteration of T cell functions in the elderly. The restoration of immunological functions of the aged individuals is possible and might be beneficial for them to cope with various diseases associated with aging. Physiological thymic atrophy is controlled by both extrathymic and intrathymic factors, and is not a totally irreversible process. The process of thymic atrophy might be explained by further understanding of the relationship between the neuroendocrine and the immune systems.

Differential age-change in the numbers of CD4+CD45RA+ and CD4+CD29+ T cell subsets in human peripheral blood

Peripheral blood mononuclear cells were obtained from people ranging in age from newborn to 102 years old and analyzed by dual color flow cytometer in terms of number and percentage of various subsets of T cells, B cells and natural killer cells (CD3, 4, 5, 8, 11b, 19, 20, 21, 25, 29, 45RA and 56). Numbers of T cells (CD3+ or CD5+ cells) significantly declined at the 3rd decade as compared with those of younger people, stayed at a relatively constant level between the 3rd and the 7th decade and gradually declined thereafter. In T cell subsets, both CD4 and CD8 positive positive cells decreased with age, but a decrease was more pronounced in the latter, showing an age-related increase of CD4/CD8 ratio. The most interesting finding was a contrasting age-change in two subsets of CD4+ T cells; i.e. a subset of suppressor inducer T cells (CD4+CD45RA+ naive cells) decreased with age, while a subset of helper inducer T cells (CD4+CD29+ memory cells) increased with age. CD20+ B cells also decreased with age in a manner similar to that observed in T cells. Natural killer cells (CD56) showed an increase in numbers with age. The relationship between these changes in various subsets of peripheral blood leukocytes and the age-related decline in immune functions has been discussed.

Immunohistochemical evaluation of bone marrow lymphoid nodules in chronic myeloproliferative disorders

One hundred and seventy bone marrow biopsies from patients with chronic myeloproliferative disorders (CMPDs) were evaluated for the presence of lymphoid nodules (LNs) and were immunostained using a panel of monoclonal antibodies (UCHL1, 4KB5 and L26) recognizing different lymphocyte antigens. LNs were found in 35% of cases of idiopathic thrombocythaemia, 24.6% of myelofibrosis/osteomyelosclerosis, 18.2% of polycythaemia vera 12.1% of chronic myeloid leukaemia and 19.2% of borderline cases. Varying degrees of immunohistochemical positivity for the three antibodies tested were found. LNs were always made up of variable proportions of both T- and B-lymphocytes with a prevalence of T-cells. This latter observation suggests that bone marrow LNs in CMPDs could be an expression of reactivity.

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.

Distribution of immunoglobulin containing cells in human bone marrow of patients with leukemia

In the bone marrow of leukemic patients (31 cases), the number of immunoglobulin containing cells per unit square significantly decreased to the level of approximately 20-50% of the age-matched control, although the serum level of immunoglobulin in these patients was almost comparable to the control level. The number of immunoglobulin containing cells in the bone marrow was inversely related with the degree of infiltration of leukemic cells and the correlation of Ig-G containing cell count (Y) and percentage of blast cells (X) was Y = 91.8-1.9X (r = -0.436, P less than 0.05). Follow-up examination of the bone marrow after chemotherapy revealed that the recovery of the number of immunoglobulin containing cells in the remission state appeared to occur in younger patients, but not in older ones.

Immuno- and enzyme-histo/cytochemical analysis of resin sections and cell suspensions: a comprehensive diagnosis of bone marrow on a single aspiration sample

A protocol is described in which a single bone marrow aspiration specimen is used to prepare resin sections and cell suspensions. Using this protocol, a full battery of morphological, enzyme-histochemical, immuno-histochemical and cyto-pathological techniques can be applied. This allows a definitive bone marrow diagnosis to be established without resorting to bone marrow biopsy in the majority of patients.