Immune recovery following bone marrow transplantation

83 patients undergoing allogeneic or autologous BMT because of haematologic malignancies have been studied before and after transplantation at different intervals. The determinations consisted of lymphocyte counts, E-rosetting, lymphoblastic response, evaluation of serum immunoglobulin levels, skin testing, and in a smaller part of the patients surface marker studies using monoclonal antibodies of the BL-series. At first after BMT the lymphocyte and T cell counts went to normal between 4-18 weeks post transplant, about 4 weeks earlier in autologous than in allogeneic BMT. T suppressor cells showed an early increase compared to T helper cells which normalized much slower about 6 months after BMT. Lymphoblastic responses, however, tended to normal not before the second half of the first year both in autologous and allogeneic transplantation. Skin test reactivity became normal during the 2nd and 3rd year posttransplant, which was more complete in autologous than in allogeneic BMT. The IgG and IgM levels were depressed for half a year and IgA levels for 2 years. The most striking aspect was the multiphase course of lymphoblastic response in every individual patient. We suggest this to be the expression of sequential differentiation of donor lymphocytes.     

Alloreactive memory T cells are responsible for the persistence of graft-versus-host disease

Graft-vs-host disease (GVHD) is caused by a donor T cell anti-host reaction that evolves over several weeks to months, suggesting a requirement for persistent alloreactive T cells. Using the C3H.SW anti-C57BL/6 (B6) mouse model of human GVHD directed against minor histocompatibility Ags, we found that donor CD8(+) T cells secreting high levels of IFN-gamma in GVHD B6 mice receiving C3H.SW naive CD8(+) T cells peaked by day 14, declined by day 28 after transplantation, and persisted thereafter, corresponding to the kinetics of a memory T cell response. Donor CD8(+) T cells recovered on day 42 after allogeneic bone marrow transplantation expressed the phenotype of CD44(high)CD122(high)CD25(low), were able to homeostatically survive in response to IL-2, IL-7, and IL-15 and rapidly proliferated upon restimulation with host dendritic cells. Both allogeneic effector memory (CD44(high)CD62L(low)) and central memory (CD44(high)CD62L(high)) CD8(+) T cells were identified in B6 mice with ongoing GVHD, with effector memory CD8(+) T cells as the dominant (>80%) population. Administration of these allogeneic memory CD8(+) T cells into secondary B6 recipients caused virulent GVHD. A similar allogeneic memory CD4(+) T cell population with the ability to mediate persistent GVHD was also identified in BALB/b mice receiving minor histocompatibility Ag-mismatched B6 T cell-replete bone marrow transplantation. These results indicate that allogeneic memory T cells are generated in vivo during GVH reactions and are able to cause GVHD, resulting in persistent host tissue injury. Thus, in vivo blockade of both alloreactive effector and memory T cell-mediated host tissue injury may prove to be valuable for GVHD prevention and treatment.     

Effect of biosynthetic methionyl growth hormone (GH) therapy on the immune function in GH-deficient children

The ability of growth hormone (GH) to influence certain immune functions has been studied in 21 GH-deficient children aged 1.8-17.7 years, before and during therapy with biosynthetic methionyl-hGH (12 IU/m2) injected intramuscularly 3 times weekly. Blood was collected prior to GH treatment, then after 1 week, again at 3-6 months, and finally at 9-12 months of therapy. We studied (1) the distribution of the T lymphocyte subpopulations: T total (CD3), helper/inducer (CD4) and suppressor/cytotoxic (CD8) cells, using monoclonal antibodies (OKT3, OKT4, OKT8) and (2) the in vitro IgM production stimulated by pokeweed mitogen. Pretreatment CD3, CD4, CD8 values were within the normal range. They did not change after 1 week of GH therapy. Following 3-6 months of GH treatment, CD3 significantly increased (p less than 0.001), CD4 decreased (p less than 0.01), CD8 increased (p less than 0.001) and the CD4/CD8 ratio decreased (p less than 0.001). At 9-12 months of therapy, the percentages of the different groups of T cells was not significantly different from the pretreatment values. In vitro IgM production before and following 3-6 months of GH treatment was significantly lower (p less than 0.005) than that of 15 age-matched controls. At 9-12 months, GH therapy restored the in vitro IgM production. No variations in the levels of serum immunoglobulins were observed throughout the treatment period. These data suggest that GH plays a role in the development of the immune function in children.     

Immune recovery after allogeneic stem cell transplantation: study of 19 patients

The aim of this study was to access average delays for novogeneration of myeloid and lymphoid cells after allogeneic bone marrow transplantation (BMT) outcome and factors affecting this organization. A prospective analysis over 2 years (01/01/07 to 31/12/08) enrolling 19 children treated with allogeneic intrafamilial bone marrow transplantation. Indications for bone marrow transplantation were: aplastic anemia (3 cases), bemoglobinopathies (9 cases), myelodysplastic syndrome (1 case) and primary immunodeficiency (6 cases). Different conditioning regiments were used according to the indication. The study of immune reconstitution was based on the quantitative determination of immunoglobulin and lymphocyte subpopulation. These tests were routinely requested to 1 month, 2 months, 3 months, 6 months, 9 months and 12 months. The average time of engraftment was 18 days (12-24). A rate of CD4+T lymphocytes>200/mm3 was provided within an average of 2,5 months (1-7). The average time to obtain CD8+T lymphocytes>200/mm3 was 2 months (1-5). The humoral immune reconstitution was made within an average of 2 months (1-4). A report of CD4+/CD8+T lymphocytes>I was obtained within 10 months and a half (1-24). Univaried analysis showed a correlation between the bone marrow sex matched and the faster reorganization of CD8+T cells (p=0.042). A quantity of CD34+>6 10(6)/kg was significantly associated with the recapture of a formula lymphocyte CD4+/CD8+T>1 (p=0.03) Immune recovery post bone marrow transplantation in children begins with myeloid lineage then lymphoid B then lymphoid T The inversion of the report CD4+/CD8+T lymphocytes, seems to be influenced by the high contain of CD34+cells in the graft as well as the type of conditioning.     

同种异基因骨髓移植GVHD动物模型的建立及其病理生理学机制初探

目的：建立稳定的异基因骨髓移植GVHD（移植物抗宿主病）动物模型,并初步了解其病理生理学机制。方法：以BALB／c（H-2^d）雌性小鼠为受者,接受8Gy致死剂量的。Co全身照射后,输注雄性C57BL／6（H-2^b）供鼠的脾细胞和骨髓细胞,观察受鼠的体征、造血功能恢复及生存时间的变化,并进行病理学、嵌合体和T细胞亚群及相关细胞因子的检查。结果：模型组小鼠在移植后出现了典型的GVHD症状;肠、肝、脾、皮肤的病理学分析均属于Ⅳ度GVHD;嵌合体植入成功;以7、14和21d为检测时间点,发现模型组鼠体内T细胞亚群移植后较移植前CD3^＋CD4^＋T细胞数量减少,CD3＋CD8＋T细胞显著升高,CD4^＋和CD8^＋T细胞比例严重倒置,随着时间变化比值会逐渐升高,但仍然处于较显著的倒置水平;血清中IFN-γ、TNF-α在移植后＋7d表达显著增高,尤其是IFN-γ的表达在＋7d达峰值;IL-4和IL-10的水平在移植前后几乎没有变化。结论：建立了稳定的GVHD动物模型;此模型发病过程中,CD8^＋T细胞介导的CTL细胞毒性作用可能要大于CD4＋Th介导的细胞因子效应;IFN-γ、TNF-α炎症因子在GVHD的早期发挥重要作用;IL-4、IL-10的低水平分泌与急性GVHD的高发病率有关。     

Kinetics of the anti-recipient cytotoxic cell response of mice with minor histocompatibility antigen graft-vs-host disease

The kinetics of the anti-recipient cytotoxic cell response of spleen cells from mice undergoing graft-vs-host disease (GVHD) induced to minor histocompatibility antigens were studied. Two population of cytotoxic cells were identified. Cytotoxic T lymphocytes (CTL) were present in recipient spleens 2 and 3 wk after transplantation but disappeared from the spleens before the onset of clinical disease. Cytotoxic T lymphocyte precursors (CTLp) were first detected in recipient spleens 2 wk after transplantation and were present during clinical disease. CTL may function as effectors in GVHD induced to minor histocompatibility antigens.     

Phenotype and function of engrafted maternal T cells in patients with severe combined immunodeficiency

Engrafted maternal T cells from two patients with severe combined immunodeficiency (SCID) and graft-vs-host disease (GVHD) were characterized for surface phenotype, function, and ecto-5'-nucleotidase (ecto-5'-NT) activity. The majority of engrafted T cells from both patients were T6-, T3+, and Ia+; the ratio of T4+:T8+ cells varied from 0.89 to 3.1 for Patient 1 and was 0.17 for Patient 2. The sum of T4+ + T8+ cells was greater than the number of T3+ cells, and approximately one-third of the patients' T cells were T3-. Two-color immunofluorescent staining showed that one-third of the T cells from Patient 1 had a novel cell surface phenotype (T6-, T3-, T4+, T8+) that was not previously described. T cells from Patient 1 failed to proliferate in response to allogeneic cells or specific antigen and provided little help for PWM-driven Ig synthesis in vitro. However, they did suppress Ig synthesis in vitro and proliferate in response to PHA and Con A; thus they appeared to be more mature than the T cells of Patient 2 and of most previously reported patients with SCID and maternal T cell grafts. Both patients lacked detectable lymphocyte ecto-5'-NT activity, suggesting that either the ecto-5'-NT activity of maternal T cells is lost after engraftment or that a specific subset(s) of ecto-5'-NT-negative maternal T cells predominates in infants with SCID and GVHD. Thus, in vitro T cell function and the proportions of T cells bearing T4 and T8 may vary in SCID patients with maternal T cell grafts. However, the presence of the Ia antigen and the absence of ecto-5'-NT activity may be consistent features of activated maternal T cells responsible for GVHD.     

Host resistance to cyclosporine induced syngeneic graft-versus-host disease. Requirement for two distinct lymphocyte subsets

Cyclosporine is crucial for the prevention of organ allograft rejection and allogeneic graft-vs-host disease (GVHD). Despite its potent immunosuppressive activity, cyclosporine elicits a T cell-mediated autoimmune syndrome after autologous or syngeneic bone marrow transplantation, which has been termed syngeneic GVHD (SGVHD). Recent studies have shown that for disease manifestation, a cytoxan and radiation-sensitive T cell dependent host resistance mechanism must be eliminated, allowing the clonal expansion of autoreactive cells. This report characterizes the autoregulatory lymphocyte population, present in normal animals, capable of inhibiting the adoptive transfer of SGVHD. First, twice the number of unfractionated splenocytes from normal animals to those from autoimmune donors ensured complete inhibition of the adoptive transfer of immune reactivity. Second, the phenotype of this host resistance mechanism in normal splenocytes involves dual regulatory T cell subsets. A helper/inducer subset (W3/25+) must be cotransferred with a cytotoxic/suppressor subset (OX8+) in a ratio that approximates the normal ratio in normal unfractionated splenocytes in order to affect inhibition of the transfer of SGVHD. Moreover the specific inducer regulatory activity resides in the OX22-, W3/25+ subset of Th cells.     

DNA supercoiled domains and radiosensitivity of subpopulations of human peripheral blood lymphocytes

Enriched human B- and T-lymphocyte subpopulations were isolated by means of a Percoll step gradient centrifugation procedure. 60Co gamma-irradiation dose-response curves for these subpopulations were obtained by applying a modified nucleoid sedimentation technique, which was also employed for the determination of the superhelical content by means of ethidium bromide intercalation. Although a similarity in the average superhelical density of B- and T1-lymphocytes was shown, B-lymphocytes exhibited a more pronounced reduction in sedimentation ratio, suggesting a higher radiosusceptibility than the T1-lymphocytes. By applying the single hit kinetics of the target theory to the dose-response curves, an estimation of the supercoil domain sizes was made: B- cells, 5.5 X 10(9), 1.78 X 10(9) and 7.78 X 10(8) D; T-cells, 4.55 X 10(9), 1.75 X 10(9) and 7.67 X 10(8) D. The differences in radiosensitivity of lymphocyte subpopulations can not, therefore, be entirely ascribed to differences in DNA superstructure.     

Immune reconstitution in patients with Fanconi anemia after allogeneic bone marrow transplantation

Background aimsFanconi anemia is an autosomal recessive or X-linked genetic disorder characterized by bone marrow (BM) failure/aplasia. Failure of hematopoiesis results in depletion of the BM stem cell reservoir, which leads to severe anemia, neutropenia and thrombocytopenia, frequently requiring therapeutic interventions, including hematopoietic stem cell transplantation (HSCT). Successful BM transplantation (BMT) requires reconstitution of normal immunity.MethodsIn the present study, we performed a detailed analysis of the distribution of peripheral blood subsets of T, B and natural killer (NK) lymphocytes in 23 patients with Fanconi anemia before and after BMT on days +30, +60, +100, +180, +270 and +360. In parallel, we evaluated the effect of related versus unrelated donor marrow as well as the presence of graft-versus-host disease (GVHD).ResultsAfter transplantation, we found different kinetics of recovery for the distinct major subsets of lymphocytes. NK cells were the first to recover, followed by cytotoxic CD8⁺ T cells and B cells, and finally CD4⁺ helper T cells. Early lymphocyte recovery was at the expense of memory cells, potentially derived from the graft, whereas recent thymic emigrant (CD31⁺ CD45RA⁺) and naive CD4⁺ or CD8⁺ T cells rose only at 6 months after HSCT, in the presence of immunosuppressive GVHD prophylactic agents. Only slight differences were observed in the early recovery of cytotoxic CD8⁺ T cells among those cases receiving a graft from a related donor versus an unrelated donor. Patients with GVHD displayed a markedly delayed recovery of NK cells and B cells as well as of regulatory T cells and both early thymic emigrant and total CD4⁺ T cells.ConclusionsOur results support the utility of post-transplant monitoring of a peripheral blood lymphocyte subset for improved follow-up of patients with Fanconi anemia undergoing BMT.     

Clonal analysis of murine graft-vs-host disease. I. Phenotypic and functional analysis of T lymphocyte clones

Acute and chronic graft-vs-host disease (GVHD) due to non-MHC histocompatibility differences differ histopathologically. Acute GVHD is characterized by the cytotoxic destruction of recipient tissues, whereas chronic GVHD is characterized by increased collagen deposition. In an attempt to determine if acute and chronic GVHD represent two phases of the same pathophysiologic process or two distinct processes, the T lymphocytes from the C57BL/6 (B6) recipients of LP spleen cells (non-H-2 GVHD) have been cloned and compared to clones from immune mice (LP anti-B6). Acute GVHD (G) clones were established on day 10-14 posttransplant and chronic GVHD (CG) clones on day 50 from animals with clinical chronic GVHD. Immune (I) clones were established 10 to 14 days after immunization. All I clones exhibited B6-specific blastogenesis and cytotoxicity and had a Thy-1.2+, Lyt-2.2+, L3T4- phenotype. All CG clones were noncytotoxic, had I-Ab-specific blastogenesis, and had a Thy-1.2+, Lyt-2.2-, L3T4+ phenotype. The acute GVHD (G) clones were heterogeneous. Fourteen of 23 clones exhibited B6-specific blastogenesis and had a Lyt-2.2+, L3T4- phenotype (B6-G clones). Seven of 9 B6-G clones were cytotoxic for B6 targets. Nine of 23 G clones exhibited I-Ab-specific blastogenesis, and all but one clone had a Lyt-2.2-, L3T4+ phenotype as the did CG clones. Thus, the principal clonogenic T lymphocytes from mice with acute and chronic GVHD differ in terms of 1) their antigenic specificity, 2) their cytotoxic capacity, and 3) their surface phenotype. The presence of I-Ab-specific T lymphocytes with a phenotype identical to CG clones early after transplantation suggests that the immunologic events that result in chronic GVHD begin soon after transplantation. These results indicate that acute GVHD is due primarily to recipient-specific cytotoxic donor T lymphocytes, whereas chronic GVHD is due to autoreactive helper T lymphocytes.     

CD4+ T cells generated de novo from donor hemopoietic stem cells mediate the evolution from acute to chronic graft-versus-host disease

Acute and chronic graft-versus-host disease (GVHD) remain the major complications limiting the efficacy of allogeneic hemopoietic stem cell transplantation. Chronic GVHD can evolve from acute GVHD, or in some cases may overlap with acute GVHD, but how acute GVHD evolves to chronic GVHD is unknown. In this study, in a classical CD8+ T cell-dependent mouse model, we found that pathogenic donor CD4+ T cells developed from engrafted hemopoietic stem cells (HSCs) in C57BL/6SJL(B6/SJL, H-2(b)) mice suffering from acute GVHD after receiving donor CD8+ T cells and HSCs from C3H.SW mice (H-2(b)). These CD4+ T cells were activated, infiltrated into GVHD target tissues, and produced high levels of IFN-gamma. These in vivo-generated CD4+ T cells caused lesions characteristic of chronic GVHD when adoptively transferred into secondary allogeneic recipients and also caused GVHD when administered into autologous C3H.SW recipients. The in vivo generation of pathogenic CD4+ T cells from engrafted donor HSCs was thymopoiesis dependent. Keratinocyte growth factor treatment improved the reconstitution of recipient thymic dendritic cells in CD8+ T cell-repleted allogeneic hemopoietic stem cell transplantation and prevented the development of pathogenic donor CD4+ T cells. These results suggest that de novo-generated donor CD4+ T cells, arising during acute graft-versus-host reactions, are key contributors to the evolution from acute to chronic GVHD. Preventing or limiting thymic damage may directly ameliorate chronic GVHD.     

Mononuclear cell infiltrate, HLA-Dr expression and proliferation in 37 acoustic schwannomas

Frozen sections from 37 schwannomas of the VIII nerve were reacted with a panel of monoclonal antibodies to macrophage, lymphocyte, HLA-Dr invariant chain and nuclear proliferation antigens. A moderate number of macrophages was demonstrated in 96% of tumours. CD8- and CD4-lymphocytes were detected in slightly smaller numbers in up to 87% and 23% of tumours respectively. B-lymphocytes were present in only 2/32 cases and NK-cells were absent from all 16 cases tested. HLA-Dr antigen was expressed by macrophages in most cases and by tumour cells in 13/24 tumours. These findings may represent evidence for a degree of cellular immune response. Occasional cells featuring nuclear proliferation were detected in 15/27 cases.     

T Cell Activation but Not Polyfunctionality after Primary HIV Infection Predicts Control of Viral Load and Length of the Time without Therapy

Objective

Immune changes occurring after primary HIV infection (PHI) have a pivotal relevance. Our objective was to characterize the polyfunctionality of immune response triggered by PHI, and to characterize immune activation and regulatory T cells, correlating such features to disease progression.

Patients and Methods

We followed 11 patients experiencing PHI for 4 years. By polychromatic flow cytometry, we studied every month, for the first 6 months, T lymphocyte polyfunctionality after cell stimulation with peptides derived from HIV-1 gag and nef. Tregs were identified by flow cytometry, and T cell activation studied by CD38 and HLA-DR expression.

Results

An increase of anti-gag and anti-nef CD8+ specific T cells was observed 3 months after PHI; however, truly polyfunctional T cells, also able to produce IL-2, were never found. No gross changes in Tregs were present. T lymphocyte activation was maximal 1 and 2 months after PHI, and significantly decreased in the following period. The level of activation two months after PHI was strictly correlated to the plasma viral load 1 year after infection, and significantly influenced the length of period without therapy. Indeed, 80% of patients with less than the median value of activated CD8+ (15.5%) or CD4+ (0.9%) T cells remained free of therapy for >46 months, while all patients over the median value had to start treatment within 26 months.

Conclusions

T cell activation after PHI, more than T cell polyfunctionality or Tregs, is a predictive marker for the control of viral load and for the time required to start treatment.     

急性病毒性肝炎患者外周血T 细胞亚群的检测和分析

目的:检测急性甲、乙型病毒性肝炎患者外周血T淋巴细胞亚群变化,探讨其对疗效和预后意义。方法:采用APAAP桥联酶标法检测115例急性甲、乙型病毒型肝炎患者外周血CD3+、CD4+、CD8+T细胞亚群比例,计算CD4+/CD8+值。并检测了34例患者治疗前后T淋巴细胞亚群变化。结果:115例急性甲、乙型病毒性肝炎患者外周血CD3+、CD4+T细胞比例及CD4+/CD8+值均低于正常对照组(P<0.05),而CD8+T细胞比例均高于正常对照组(P<0.01)。6例无明显疗效者,各亚群比例在治疗前后无显著差异(P>0.05)。28例有明显疗效者,治疗后各亚群比例恢复正常水平,与治疗前相比差别具有统计学意义(P<0.05)。结论:急性甲、乙型病毒性肝炎患者外周血CD4+/CD8+T细胞比值可在一定程度上反映疗效及预后。     

CD8+ Foxp3+ regulatory T cells are induced during graft-versus-host disease and mitigate disease severity

Regulatory T cells (Tregs), in particular CD4(+) Foxp3(+) T cells, have been shown to play an important role in the maintenance of tolerance after allogeneic stem cell transplantation. In the current study, we have identified a population of CD8(+) Foxp3(+) T cells that are induced early during graft-versus-host disease (GVHD), constitute a significant percentage of the entire Treg population, and are present in all major GVHD target organs. These cells expressed many of the same cell surface molecules as found on CD4(+) Tregs and potently suppressed in vitro alloreactive T cell responses. Induction of these cells correlated positively with the degree of MHC disparity between donor and recipient and was significantly greater than that observed for CD4(+)-induced Tregs (iTregs) in nearly all tissue sites. Mice that lacked the ability to make both CD8(+) and CD4(+) iTregs had accelerated GVHD mortality compared with animals that were competent to make both iTreg populations. The absence of both iTreg populations was associated with significantly greater expansion of activated donor T cells and increased numbers of CD4(+) and CD8(+) T cells that secreted IFN-γ and IL-17. The presence of CD8(+) iTregs, however, was sufficient to prevent increased GVHD mortality in the complete absence of CD4(+) Tregs, indicating at least one functional iTreg population was sufficient to prevent an exacerbation in GVHD severity, and that CD8(+) iTregs could compensate for CD4(+) iTregs. These studies define a novel population of CD8(+) Tregs that play a role in mitigating the severity of GVHD after allogeneic stem cell transplantation.     

Phenotypic and functional evaluation of suppressor cells in normal pregnancy and in chronic aborters

To evaluate the potential role of immunoregulatory cells modulating the maternal immunologic response during pregnancy, we carried out phenotypic and functional studies in patients with normal obstetrical histories during each trimester and in patients with chronic idiopathic spontaneous abortions. Using monoclonal antibodies (Ortho), total numbers of T cells (T3+) and T4+ cells progressively increased during pregnancy (compared to nonpregnant controls) and then declined in the third trimester. Increased percentages of T8+, T10+, and Ia+ cells were found in the third trimester. The relative decline in numbers of T4+ cells, with increased numbers of T8+ cells, led to a significantly reduced T4/T8 ratio in the third trimester. Histamine receptors on T cells were quantitated by an immunofluorescent technique. Significantly reduced numbers of H1-type receptors were noted during the second trimester of pregnancy and this was associated with a decreased H1/H2 ratio. Functionally, histamine-induced suppression was measured in a lymphocyte proliferation assay. Patients in the first and second trimester of pregnancy had greater histamine-induced suppression of phytohemagglutinin (PHA)-stimulated proliferation at high concentrations of histamine (10(-3) to 10(-7)) but less suppression at the lower concentrations (10(-9) to 10(-11) M), compared to nonpregnant controls. In contrast, patients studied in the third trimester failed to respond to any concentration of histamine. MLC-induced suppressor activity was generated by incubating the maternal cells with either paternal or third-party mononuclear cells for 2 or 6 days and assaying the cell-free supernatant for its suppressive effects on PHA-stimulated proliferation. Maternal responses to paternal cells did not result in significant suppression in 2-day supernatants during any trimester but by 6 days the suppressive activity was equivalent to non-pregnant controls in patients during the first and second trimester. Maternal responses to third party cells was greater during the second trimester than either the first or third trimesters in both 2- and 6-day supernatants. Patients with histories of chronic idiopathic spontaneous abortions, who were not pregnant at the time of study, exhibited normal numbers of T-cell subsets and T4/T8 ratios. Numbers of both H1 and H2 receptor bearing T cells were proportionally reduced, resulting in a normal H1/H2 ratio. Despite having decreased numbers of H1 and H2 receptor bearing cells, histamine-induced suppression of PHA-stimulated proliferation was comparable to nonpregnant controls over the concentration range (10(-3) to 10(-11) M) employed.(ABSTRACT TRUNCATED AT 400 WORDS)     

Lymphocyte subpopulation state of the human lung during prenatal development]

Distribution of surface lymphocyte markers was assessed in foetus lung by cytofluorimetry using monoclonal antibodies produced by "Ortho Diagnostic systems" and "Becton Dickinson". Seven lymphocyte subpopulations were detected in developing lungs even at the pseudoglandular stage (8-15 weeks). There was a significant increase in these lymphocyte subpopulations in canalicular stage. Quantity of T3+ cells increased 8-fold and B-cells 10-fold. There was a tendency to increased number of cortical thymocytes (T6+), and to decreased ratio T6+/T3+ lymphocytes. The ratio of immunoregulatory lymphocyte subpopulations (T4+/T8+) resembled that of these subpopulations in adult human lung rather than in cord blood. In canalicular stage the share of lung lymphoid cells in S-phase was decreased.     

Increased Bone Marrow (BM) Plasma Level of Soluble CD30 and Correlations with BM Plasma Level of Interferon (IFN)-γ, CD4/CD8 T-Cell Ratio and Disease Severity in Aplastic Anemia

Idiopathic aplastic anemia (AA) is an immune-mediated bone marrow failure syndrome. Immune abnormalities such as decreased lymphocyte counts, inverted CD4/CD8 T-cell ratio and increased IFN-γ-producing T cells have been found in AA. CD30, a surface protein belonging to the tumor necrosis factor receptor family and releasing from cell surface as a soluble form (sCD30) after activation, marks a subset of activated T cells secreting IFN-γ when exposed to allogeneic antigens. Our study found elevated BM plasma levels of sCD30 in patients with SAA, which were closely correlated with disease severity, including absolute lymphocyte count (ALC) and absolute netrophil count (ANC). We also noted that sCD30 levels were positively correlated with plasma IFN-γ levels and CD4/CD8 T-cell ratio in patients with SAA. In order to explain these phenomena, we stimulated T cells with alloantigen in vitro and found that CD30⁺ T cells were the major source of IFN-γ, and induced CD30⁺ T cells from patients with SAA produced significantly more IFN-γ than that from healthy individuals. In addition, increased proportion of CD8⁺ T cells in AA showed enhanced allogeneic response by the fact that they expressed more CD30 during allogeneic stimulation. sCD30 levels decreased in patients responded to immunosuppressive therapy. In conclusion, elevated BM plasma levels of sCD30 reflected the enhanced CD30⁺ T cell-mediated immune response in SAA. CD30 as a molecular marker that transiently expresses on IFN-γ-producing T cells, may participate in mediating bone marrow failure in AA, which also can facilitate our understanding of AA pathogenesis to identify new therapeutic targets.