Surface characteristics of synovial fluid and peripheral blood lymphocytes in inflammatory arthritis

In order to characterize the T- and B-cell populations of inflammatory arthritides, synovial fluid and peripheral blood lymphocytes from patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA), and rheumatoid variant diseases (RV) were studied. Normal peripheral blood lymphocytes were examined as controls. T cells were identified by spontaneous sheep red blood cell (E) rosette formation. B cells were determined by complement receptor lymphocyte (EAC) rosette formation and by the presence of surface immunoglobulins (SIg) utilizing fluoresceinated polyvalent antiglobulin. Synovial fluids were analyzed in terms of duration, mucin quality, white cell count, and differential. Synovial fluid and peripheral blood lymphocytes from patients with RA and RV were distributed in T- and B-cell percentages similar to those found in normal peripheral blood. In contrast, significant T-cell depression was observed in the percentage of synovial fluid and peripheral blood lymphocytes of SLE and JRA patients. This depression was apparent in comparison with normal peripheral blood and with the synovial fluid and peripheral blood from RA patients. B-cell percentages were similar in all patient groups and in comparison to normal peripheral blood lymphocytes. No differences were noted in B-cell percentages when the EAC and SIg techniques of identification were compared. The percentage of cells bearing neither T- nor B-cell markers (null cells) was enumerated for each patient group and found to be significantly elevated in the synovial fluid and peripheral blood of SLE and JRA patients. Though the mean synovial fluid and peripheral blood null cell percentages in RA patients were similar to those in controls, a definite bimodal distribution was found in the synovial fluids. These data suggest that evaluation of T-, B-, and null-cell populations may be clinically useful in differentiating patients with SLE and JRA from those with rheumatoid arthritis and variant diseases.     

Cell-mediated immunity in rheumatic diseases

Lymphocyte responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen were tested in normal patients and in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), scleroderma (PSS), other connective tissue disease, and other illnesses. The relationship of lymphocyte response to diagnosis, therapy, and T- and B-lymphocyte populations was analyzed. Additional studies included the determination of proliferative responses of various combinations of purified T and B lymphocytes cultured with plant mitogens. Lymphocytes from patients with RA and SLE incorporated significantly less thymidine in the presence of plant mitogens as compared to normal and comparably ill subjects. Treatment had no effect on mitogen response. Responses to all three mitogens correlated closely in patients with RA, SLE, or PSS; no correlation was noted between the response to mitogen of lymphocytes in culture and the number of T cell ultured.     

Depressed lymphocyte responses to wheat germ agglutinin and other mitogens in treated coeliac disease patients

Abstract This report investigates the possibility that inappropriate lymphocyte responses to wheat germ agglutinin (WGA), a mitogen found in wheat which influences proliferation of and immunoglobulin (Ig) synthesis by peripheral blood mononuclear cells (PBMC), may account for some of the immunological dysfunction noted in coeliac disease. The PBMC were prepared from healthy controls and 16 patients with coeliac disease who had received a gluten-free diet for periods of 1 month to over 20 years. There was no difference in the proliferative responses of PBMC from the patients and normal subjects to optimal mitogenic concentrations of phytohaemagglutinin (PHA) or Concanavalin A (Con A), but the responses of the cells of the patients to pokeweed mitogen (PWM) and to a suboptimal concentration of Con A were reduced. The proliferative response induced by WGA in PBMC from treated coeliac patients was significantly depressed compared with controls. The synthesis of Ig by PWM-stimulated PBMC, and the Con A induced suppression of this synthesis, was the same in cultures of PBMC from the patients or the controls. There was no difference in the effect of WGA on Ig synthesis between the patients and controls. It is concluded that there is no difference in the effect of WGA on Ig synthesis by PBMC from coeliac disease patients or controls, but that lymphocytes from coeliac disease patients proliferate poorly in response to WGA.     

Production of B-cell growth factor interleukin 2 and gamma interferon by peripheral blood lymphocytes from patients with chronic lymphocytic leukemia of B-cell type

Chronic lymphocytic leukemia of B-cell type (B-CLL) is a malignant disease characterized by monoclonal proliferation of small lymphocytes of B-cell origin, usually associated with suppression of polyclonal B-cell activation (i.e., proliferation and differentiation). Normal human B-cell proliferation is controlled by different T-cell-derived lymphokines, including interleukin 2 (IL2) and gamma interferon (gamma-IFN), that account for the majority of the B-cell growth factor (BCGF) activity produced by mitogen-activated peripheral blood mononuclear cells (PBMCs). We have previously shown an increased and dysregulated secretion of IL2 in peripheral blood from patients with B-CLL. BCGF, IL2, and gamma-IFN productions by phytohemagglutinin (PHA)-stimulated PBMCs were investigated in 13 patients with active untreated B-CLL and 11 healthy donors. B-CLL PBMCs produced a significant amount of BCGF (6 U/ml) despite the low percentage of T cells (10%) associated with this disease as compared with that found in healthy donors (61%). BCGF production in normal controls and B-CLL patients was tripled after irradiation of PBMCs or addition of indomethacin. gamma-IFN secretion in B-CLL patients was decreased when compared with normal controls. Therefore, when gamma-IFN was calculated per fixed number of T cells, production was significantly higher in B-CLL patients than in normal controls, showing a dilution of the productive cells. This study suggests that T cells from B-CLL patients are functional in terms of BCGF production despite their decreased percentage and abnormalities in surface markers.     

Abnormal phytohemagglutinin-induced T-cell proliferative responses in Hodgkin's disease

Optimal conditions were established for evaluating the phytohemagglutinin-induced proliferative responses of purified peripheral blood T lymphocytes. This assay was utilized to determine whether T cells (in the absence of monocytes and serum inhibitory factors) from patients with Hodgkin's disease were defective in their ability to proliferative in response to optimal (50 microgram/ml) and suboptimal (25 and 12.5 microgram/ml) concentrations of phytohemagglutinin. T cells from 6 of 12 untreated patients exhibited 6- day proliferative responses below the range of 15 control subjects using optimal mitogen concentrations, and 9 of 12 patients exhibited subnormal responses using lower concentrations. Kinetic analyses indicated that the abnormal T-cell proliferative responses were characterized by peak proliferation occurring at day 4 or 5, rather than day 6. The observed abnormalities were not related to elevations in the proportions of T cells bearing surface receptors for IgG (T gamma Cells). Our results suggest that intrinsic functional T-cell defects contribute to the impaired immunity associated with Hodgkin's disease.     

T cell subsets and cellular immunity in end-stage renal disease

The T lymphocyte population was studied by immunofluorescent staining with monoclonal antibodies and laser flow cytometry in the blood of 50 patients with end-stage renal disease undergoing long-term maintenance intermittent hemodialysis. The absolute number of T cells was lower in patients receiving dialysis for more than one year (p less than 0.001), as was the absolute count of helper T cells (p less than 0.005). In patients under 30 years of age, the absolute number of helper T cells was markedly reduced, whereas the number of suppressor/cytotoxic T lymphocytes was not changed. In patients between the ages of 30 and 60 years, both helper and suppressor cells were significantly reduced. In patients over 60 years of age, only the number of helper T cells was reduced. The in vitro response of patients' lymphocytes was reduced both in the mixed lymphocyte reaction (p less than 0.01) and after phytohemagglutinin stimulation (p less than 0.001). Natural killer cytotoxicity of patients' peripheral blood mononuclear cells, however, was unaffected.     

Correlation between immunologic function and clinical subpopulations of patients with the acquired immune deficiency syndrome

The present study was designed to determine whether there was a significant correlation between the clinical presentation of patients with AIDS or AIDS-related illnesses and the degree of their underlying immunologic abnormalities. In 17 patients who presented with opportunistic infections, the mean number of T4 lymphocytes was 34/mm3 and the mean proliferative response to phytohemagglutinin 26,000 cpm; in 12 patients who presented with Kaposi's sarcoma alone, the mean number of T4 cells was 231/mm3 and the mean proliferative response to phytohemagglutinin, 32,809 cpm; and in nine patients with the lymphadenopathy syndrome, the mean number of T4 cells was 703/mm3 and the mean proliferative response to phytohemagglutinin, 49,317 cpm. These findings suggest that those patients who present with opportunistic infections as their initial clinical manifestation of AIDS may represent a subgroup with a more severe immunologic derangement prior to clinical diagnosis. Thus, in those who have a predisposition to Kaposi's sarcoma, this disease will often develop, prior to the development of T cell dysfunction, to the degree of that in those who present with opportunistic infections. This finding is of importance in attempts to understand the pathogenesis of this syndrome and in the design of therapeutic trials.     

Characterisation of activated lymphocytes in the peripheral blood of patients with rheumatoid arthritis.

The extent and nature of lymphocyte activation in the circulation in rheumatoid arthritis (RA) was investigated. Peripheral blood lymphocytes (PBL) from RA patients and healthy controls were separated into a number of discrete fractions by density in discontinuous Ficoll density gradients. Low density (activated) lymphocytes were found at significantly higher levels in RA, particularly in patients with clinically active disease. Conversely, patients with clinically inactive RA had normal levels of activated lymphocytes. Lymphocyte populations within the ficoll gradient fractions were detected by E rosettes, staining for surface Ig, and by different avidities of EA binding. The activated population in RA was shown to be relatively depleted of T cells, enriched in surface Ig-bearing lymphocytes, and depleted of lymphocytes with high avidity EA binding. The evidence suggests that many of the activated PBL in RA are B blasts.     

Human chronic lymphocytic leukaemia. Surface markers and activation of lymphocytes.

Cell surface markers and the responses of lymphocytes to T- and B-cell mitogens were studied in 10 patients with CCL. T cells were identified as cells rosetting with sheep red blood cells (SRBC), and S-Ig was used as a marker for B lymphocytes. Most cells from all patients had a detectable amounts of S-Ig, and the percentage of cells rosetting with SRBC was low in all cases. Of the lymphocytes from these patients, 3-74% (mean 33%) were positive for the acid esterase (ANAE), which has been claimed to be a T-cell marker. However, some patients had cells that were positive for both S-Ig and ANAE. Acid esterase staining is therefore not a valid T-cell marker in chronic lymphocytic leukaemia. In cultures containing the T-cell mitogen leucoagglutinin (LA) and the T- and B-cell mitogen pokeweed mitogen (PWM) the reactivity of the lymphocytes was low. The cells responded vigorously to the T- and B-cell mitogen protein A (PA); however, the response was serum-dependent, being strong in a culture medium containing foetal calf serum (FCS), but impaired in the presence of human AB serum. Only 1 patient had cells that responded to the B-cell mitogen LPS.     

Decreased number of peripheral blood CD4 + CD29+ lymphocytes and increased in vitro spontaneous production of anti-DNA antibodies in patients with active systemic lupus erythematosus.

Flow cytometric 2-color analysis of peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed a reduction of relative and absolute number of CD4+ CD29+ cells compared to matched healthy individuals. This abnormality was more marked in patients with active/very active disease. Absolute number of CD4+ CD29+ cells was negatively correlated with spontaneous anti-DNA Ig production that we demonstrated to be a laboratory index strongly correlated with a clinical disease activity score. A decrease of the percentage of CD8+ CD29+ lymphocytes in patients with active disease was also observed.     

Human Chronic Lymphocytic Leukaemia Surface Markers and Activation of Lymphocytes

Cell surface markers and the responses of lymphocytes to T- and B-cell mitogens were studied in 10 patients with CLL. T cells were identified as cells rosetting with sheep red blood cells (SRBC), and S-Ig was used as a marker for B lymphocytes. Most cells from all patients had detectable amounts of S-Ig, and the percentage of cells rosetting with SRBC was low in all cases. Of the lymphocytes from these patients, 3–74 % (mean 33 %) were positive for the acid esterase (ANAE), which has been claimed to be a T-cell marker. However, some patients had cells that were positive for both S-Ig and ANAE. Acid esterase staining is therefore not a valid T-cell marker in chronic lymphocytic leukaemia. In cultures containing the T-cell mitogen leucoagglutinin (LA) and the T- and B-cell mitogen pokeweed mitogen (PWM) the reactivity of the lymphocytes was low. The cells responded vigorously to the T- and B-cell mitogen protein A (PA); however, the response was serum-dependent, being strong in a culture medium containing foetal calf serum (FCS), but impaired in the presence of human AB serum. Only 1 patient had cells that responded to the B-cell mitogen LPS.     

Impaired synthesis of immunoglobulin in patients with chronic lymphocytic leukemia

The cause of hypogammaglobulinemia in patients with chronic lymphocytic leukemia (CLL) is unknown. Experiments were performed to determine if sera, monocytes, or non-T cells from patients with CLL suppress the proliferative response and synthesis of immunoglobulin (Ig) following incubation with pokeweed mitogen (PWM) in cocultures with lymphocytes from normal individuals. The data indicate that sera and monocytes from patients with CLL did not suppress the proliferative response or synthesis of Ig normal non-T cells. When various numbers of normal non-T cells and CLL non-T cells were cocultured with a constant number of normal T cells, the proliferative response and the concentration of supernatant Ig decreased as the proportion of CLL non-T cells increased. Since similar results were obtained when irradiated non-T cells from normal individuals were substituted for non-T cells from patients with CLL, we believe that the decrease in proliferative response and diminished synthesis of Ig is not the result of the suppressor non-T cells but is related to the dilution of normal B cells by inert non-T cells. We conclude that these experiments serve as as in vitro model for patients with CLL and suggest that the hypogammaglobulinemia observed in this disease is related to the diluting out of normal B cells by the accumulation of neoplastic B cells in the peripheral blood, bone marrow, and lymphoid tissue of these patients.     

Aberrant expression of immunoglobulin light chain isotype in B lymphocytes from patients with monoclonal gammopathies: isotypic discordance and clonal B-cell excess

A study was made of 29 patients with monoclonal gammopathies to detect aberrations in immunoglobulin (Ig) light chain isotype expression in lymphocytes at various levels of B-cell differentiation, namely, circulating surface Ig positive (SIg+) cells, Ig-secreting cells (plaque forming cells, PFC) and mitogen-induced PFC. By using kappa-lambda analysis, two major phenotypes of aberrant Ig light chain isotype expression were found in circulating B cells at these three levels of differentiation: an absolute increase in B cells bearing the same Ig light chain isotype as that of monoclonal protein (clonal B-cell excess), and a relative decrease in those B cells (isotypic discordance). Isotypic discordance (ID) was found to be essentially negative in patients with monoclonal gammopathy of undetermined significance (MGUS) provided that they were in a stable condition. In myeloma patients, ID was found only in stage I, except for a remission case of stage III (4/7 in stage I, 0/8 in stage II, and 1/6 in stage III). ID was not restricted to a circulating SIg+ cell level but was also demonstrable at a spontaneous or pokeweed mitogen-induced PFC level. However, ID was negative at a PFC level induced by Staphylococcus aureus Cowan I. Clonal B-cell excess (CE) was frequently found in patients with active myeloma but not in stable patients (0/8 in MGUS, 1/7 in stage I, 8/8 in stage II, and 4/6 in stage III). CE was positive not only at a circulating SIg+ cell level but also at a circulating PFC level. Furthermore, patients with CE at a PFC level were found to have a higher proliferating capacity, defined as a percentage labelling index of marrow myeloma cells, than those without CE at a PFC level (P less than 0.02). ID and CE can therefore be considered as useful markers for discriminating between MGUS and myeloma, evaluating the clinical stability and predicting the clinical course.     

Lymphopenia in Sj?gren's syndrome with rheumatoid arthritis: relationship to lymphocytotoxic antibodies, cryoglobulinemia, and impaired mitogen responsiveness.

Lymphocyte subpopulation studies in 21 patients with Sj?gren's syndrome and rheumatoid arthritis revealed an absolute lymphopenia and a normal percentage of T- and SIg-cells. In one patient, a large percentage of lymphocytes bore both IgG and IgM; after cell trypsinization only IgM was resynthesized. This surface IgM was capable of binding human IgG, suggesting that the presence of multiple classes of immunoglobulins on the surface of these lymphocytes was due to surface rheumatoid factor activity. Profound lymphopenia was associated with high concentrations of cryoglobulins and the presence of lymphocytotoxic antibodies. These antibodies were broadly reactive, causing cytotoxicity of T- and SIg-cells from normal subjects, from viral and lymphoproliferative disease subjects, from different organs, and SIg-cells from human lymphoblastoid cell lines. Lymphocyte transformation after phytohemagglutinin and pokeweed mitogen stimulation was impaired in comparison to normal subjects. Warm washing of the lymphocytes and purification to greater than 80 per cent T-cells did not restore mitogen responsiveness to normal, suggesting that cell coating by an antibody and diminished responder cell number were inadequate explanations for the impaired transformation.     

Cellular immune response analysis of patients with leptospirosis

Peripheral blood mononuclear cells (PBMC) from acute leptospirosis patients with and without acute renal failure were studied in order to investigate the status of cellular immunity in this disease. We analyzed the lymphocyte subsets of leptospirosis patients by immunofluorescence and their responsiveness to the mitogens phytohemagglutinin (PHA) and pokeweed mitogen (PWM). Additionally, we investigated the effect of the patients' sera on normal PBMC proliferative response. We observed a decrease in the CD3+ and CD4+ cell subsets in patients with and without acute renal failure, or in percentage values alone in those who had recovered from renal failure. An increase in the number of B lymphocytes was observed in all patients, compared with controls. This increase in B lymphocytes was seen even in patients who had recovered from renal failure, when the number of CD3+ and CD4+ lymphocytes had already returned to normal levels. The low PHA response observed only with lymphocytes from patients with acute renal failure suggests a suppressive effect. The proliferative response to PWM was comparable to controls, even in the patients with acute renal failure. This latter result and the expansion of the B cell number could be related to leptospiral-derived factor(s). We also showed that sera from patients with and without acute renal failure exerted some inhibitory activity on normal PBMC responses to PHA and PWM. Although the redistribution of lymphocyte subsets and the serum suppressor activity were related to acute renal failure and leptospiral factor(s), we suggest that the cellular immune system was not irreversibly affected, which is compatible with the good prognosis seen in the patients studied.     

Immune status in Crohn's disease. I. Leukocyte and lymphocyte subpopulations in peripheral blood.

Proportions and absolute numbers of circulating leukocyte populations and lymphocyte subpopulations (T- and B-cells) were determined in 33 patients with Crohn's disease (group CD), and were compared with those of age- and sex-matched healthy subjects. Group CD comprised 15 patients with newly diagnosed, short-standing, and untreated CD (group CD 1) and 18 patients with long-standing, previously drug treated CD (group CD 2). All CD groups showed a significant absoulte leukocytosis, based on a significant absolute and relative increase of the neutrophils, and, as far as group CD and CD 1 were concerned, also of the absolute number of monocytes. In group CD 1, absolute lymphocyte and relative as well as absolute T-cell numbers were close to normal. In contrast, in group CD 2 absolute as well as relative numbers of lymphocytes and absolute numbers of T-cells were highly significantly reduced, whereas the reduction of the relative T-cell concentration barely reached significance. The proportion of B-cells was significantly above normal in all patient groups, the absolute number in group CD only. Also group CD 1 showed considerably, though statistically insignificantly, higher than normal absolute B-cell numbers. In group CD 1 , there was an inverse correlation between absolute T-cell numbers and disease activity, and between absolute lymphocyte numbers and duration of disease. These data indicate that there is no gross numerical reduction of the carriers of the cell-mediated immunity as a primary predisposing factor for CD, but that a reduction of these cells occurs in the circulation after the disease has started.     

Characterization of granulocyte colony-stimulating factor receptor expressed on human lymphocytes

We have studied the characterization of granulocyte colony-stimulating factor receptor (G-CSFR) in human lymphocytes. About one-third to one-quarter of the B lymphocytes from peripheral B-cell sources displayed G-CSF binding on the two-colour immunofluorescence study. The rate of G-CSFR-expressing (G-CSFR+) B cells was higher in bone marrow and cord blood than in peripheral blood, spleen and tonsil. G-CSFR expression was greater in the surface immunoglobulin D (IgD)-positive (sIgD+) B-cell population, but scarce in the sIgD- B-cell population. In tonsil, G-CSFR+ B cells were present among the cells with naive B and germinal-centre B phenotypes, but those with memory B phenotype were rarely found on triple-colour immunofluorescence analysis. Mitogen-activated, but not resting, T lymphocytes also showed G-CSF binding. Several continuous T- and B-cell lines expressed functional G-CSFR, because the addition of G-CSF enhanced the proliferative response of these cell lines. A sequence analysis of G-CSFR mRNA isoforms obtained from the T and B cells revealed that G-CSFR was derived from class I and class IV mRNA. Our results indicated that G-CSFR was constitutively expressed on the B-cell surface and was inducible in T cells.     

Analysis of immune reconstitution in children undergoing cord blood transplantation

OBJECTIVE: The aim of this study was to investigate and compare immune reconstitution in allogeneic cord blood transplantation (CBT) and bone marrow transplantation (BMT) recipients. MATERIALS AND METHODS: Twenty-three children underwent CBT from either human leukocyte antigen-identical siblings (11 cases) or unrelated donors (12 cases) were enrolled in the study, together with 23 matched children receiving BMT. Patients were analyzed 2-3 and 12-15 months after transplant. Recovery of T-, B-, and NK-lymphocyte subsets, proliferative in vitro response to mitogens, as well as cytotoxic activities, were investigated. RESULTS: CBT recipients showed a marked increase in the number of B lymphocytes as compared with patients who underwent BMT (p < 0.001). The absolute number of CD3(+) and CD8(+) T cells, as well as the proliferative response to T-cell mitogens, recovered with time after transplantation, irrespective of the source of stem cells used. Recipients of unrelated CBT had a better recovery of CD4(+) T lymphocytes (p < 0.01). Among patients experiencing acute graft-versus-host disease (GVHD), children given CBT had a much greater production of CD4(+) CD45RA(+) T cells than BMT recipients (p < 0.005). Recovery of NK cell number and innate cytotoxic activities was fast, irrespective of the source of stem cells used. CONCLUSIONS: Despite the much lower number of lymphocytes transferred with the graft, recovery of lymphocyte number and function toward normal in CBT recipients was rapid and comparable to that observed after transplantation of bone marrow progenitors. This prompt immune recovery possibly was favored by the reduced incidence and severity of GVHD observed in children who underwent CBT.     

Deficiency of mature B and T lymphocyte subsets in the blood of non-Hodgkin lymphoma patients

The expression of mature B-cell markers and T markers was determined in lymphocytes isolated from the peripheral blood (PBL) of 20 healthy and 51 patients with non-Hodgkin malignant lymphoma (NHL). The disease was classified as newly diagnosed, in remission, or being treated with chemotherapy and of low-, intermediate-, or high-grade malignancy. To avoid technical problems associated with artifacts involving cytophilic immunoglobulins (Ig), we defined mature B-cells by means of three criteria: a) expression of high surface density of Ig sufficient to allow polar movement of receptors to form a cap in an indirect immunofluorescence (IF) assay, b) expression of high density of the human leukocyte antigens DR (HLA-DR) under capped conditions, and c) expression of a 41H.16 marker exclusive to surface Ig+ B-cells. Percentages of PBL able to cap surface Ig (sIg) (lambda, K), HLA-DR (7H.3), and 41H.16 markers were significantly reduced (p less than 0.001) in all of the patients, regardless of treatment status, and the numbers of sIg+-capping cells were similarly reduced in the patients, regardless of the grade of malignancy. Studies with ring fluorescence showed mean percentages of cells expressing OKT3 and OKT4 determinants significantly reduced (P less than 0.001) but OKT8+ cells not significantly different from control. The OKT4/OKT8 ratio was reduced in all patients and did not differ significantly in relation to the degree of malignancy. We conclude that, in NHL, essentially all patients have severe abnormalities in the number of B- or T-cells needed for normal immune responses.     

In vitro regulation of immunoglobulin synthesis after marrow transplantation. I. T-cell and B-cell deficiencies in patients with and without chronic graft-versus-host disease

Twenty-four patients with aplastic anemia or acute leukemia were treated by marrow grafts from HLA-identical donors after conditioning with high doses of cyclophosphamide and/or today body irradiation. They were studied between 4 and 63 mo (median 14.2) after transplantation. Seventeen patients had chronic graft-versus-host disease (C-GVHD) and 7 were healthy. They were studied for defects in their T- and B-cell function using and indirect hemolytic plaque assay for Ig production after 6 days of culture in the presence of pokeweek mitogen. T or B cells from the patients with or without C-GVHD were cocultured with T or B cells from their HLA-identical marrow donors or unrelated normal controls. Intrinsic B-cell defects, lack of helper T-cell activity, and suppressor T-cell activity were more frequently found in patients with C-GVHD than in healthy patients. Fifteen of the 17 patients with C-GVHD showed on or more defects in their T-and B-cell function compared to only 3 of the 7 patients without C-GVHD. None of the healthy controls, including the marrow donors, showed defects in their T- and B-cell functions. These in vitro findings may be helpful in assessing the process of immune reconstitution and the immunologic aberration found after human marrow transplantation.