Assessing the role of endophytic bacteria in the halophyte Arthrocnemum macrostachyum salt tolerance.

There is an increasing interest to use halophytes for revegetation of salt affected ecosystems, as well as in understanding their mechanisms of salt tolerance. We hypothesized that bacteria from the phyllosphere of these plants might play a key role in its high tolerance to excessive salinity. Eight endophytic bacteria belonging to Bacillus and closely related genera were isolated from phyllosphere of the halophyte Arthrocnemum macrostachyum growing in salty agricultural soils. The presence of plant-growth promoting (PGP) properties, enzymatic activities and tolerance towards NaCl was determined. Effects of inoculation on seeds germination and adult plant growth under experimental NaCl treatments (0, 510 and 1030 mM NaCl) were studied. Inoculation with a consortium including the best performing bacteria improved considerably the kinetics of germination and the final germination percentage of A. macrostachyum seeds. At high NaCl concentrations (1030 mM), inoculation of plants mitigated the effects of high salinity on plant growth and physiological performance and, in addition, this consortium appears to have increased the potential of A. macrostachyum to accumulate Na+ in its shoots, thus improving sodium phytoextraction capacity. Bacteria isolated from A. macrostachyum phyllosphere seem to play an important role in plant salt tolerance under stressing salt concentrations. The combined use of A. macrostachyum and its microbiome can be an adequate tool to enhance plant adaptation and sodium phytoextraction during restoration of salt degraded soils.

Dissipation and effects of tricyclazole on soil microbial communities and rice growth as affected by amendment with alperujo compost.

The presence of pesticides in surface and groundwater has grown considerably in the last decades as a consequence of the intensive farming activity. Several studies have shown the benefits of using organic amendments to prevent losses of pesticides from runoff or leaching. A particular soil from the Guadalquivir valley was placed in open air ponds and amended at 1 or 2% (w/w) with alperujo compost (AC), a byproduct from the olive oil industry. Tricyclazole dissipation, rice growth and microbial diversity were monitored along an entire rice growing season. An increase in the net photosynthetic rate of Oryza sativa plants grown in the ponds with AC was observed. These plants produced between 1100 and 1300kgha(-1) more rice than plants from the unamended ponds. No significant differences were observed in tricyclazole dissipation, monitored for a month in soil, surface and drainage water, between the amended and unamended ponds. The structure and diversity of bacteria and fungi communities were also studied by the use of the polymerase chain reaction denaturing gel electrophoresis (PCR-DGGE) from DNA extracted directly from soil samples. The banding pattern was similar for all treatments, although the density of bands varied throughout the time. Apparently, tricyclazole did not affect the structure and diversity of bacteria and fungi communities, and this was attributed to its low bioavailability. Rice cultivation under paddy field conditions may be more efficient under the effects of this compost, due to its positive effects on soil properties, rice yield, and soil microbial diversity.

CD8+ chronic lymphocytic leukemia: an extensive characterization of a bizarre hybrid neoplasia.

Atypical chronic lymphocytic leukemia (CLL) expressing the CD8 antigen have a frequency of less than 0.5% of all cases, however, they are not yet been fully characterized. Herein a CD8+ CLL case was extensively studied. Besides the classical CLL antigen expression, an unusual presence of surface markers such as CD11c, CD56, and CD154 was observed. Moreover, gene expression of chemokine receptors belonging to the CCR family were clearly evidenced as well as mRNA for both, Th1 and Th2 cytokines. Likewise, granzyme A, B and perforin gene expression, cytotoxic T cell or NK enzymes were found. The intricate profile of membrane molecules and gene expression suggest that it could be favorable, rather than deletereous, for the maintainance of the neoplastic process.

Flow cytometric analysis of glycosylphosphatidyl-inositol-anchored proteins to assess paroxysmal nocturnal hemoglobinuria clone size.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by total or partial deficiency of membrane proteins anchored to the cell surface through a glycosylphosphatidyl-inositol (GPI) moiety. The relationship between the size of the PNH clone, determined by the expression of GPI-anchored proteins (AP; CD14, CD48, CD55, CD59, and CD66b) on erythrocytes, lymphocytes, monocytes, and granulocytes using forward and side scatter analysis, and severity of the disease was evaluated in 19 PNH patients. CD55 antigen expression did not delineate abnormal erythrocytes as well as did anti-CD59. The proportion of monocytes deficient in CD55, CD59, CD48, and CD14 (48-97%) and of granulocytes deficient in CD55, CD59, and CD66b (60-99%) was greater than the proportion of erythrocytes deficient in CD59 (24-95%) and the proportion of lymphocytes deficient in CD55 and CD59 (30-98%). There were no significant correlations among reticulocyte, leukocyte, and platelet counts and GPI-AP-deficient immunophenotypes in red and white blood cells. However, high coefficients of determination were seen between hemoglobin levels and granulocytes deficient in CD59 (r(2) = 0.76), CD55 (r(2) = 0.74), and CD66b (r(2) = 0.74) antigens and between hemoglobin and monocytes deficient in CD55 (r(2) = 0.73), CD59 (r(2) = 0.80), and CD14 (r(2) = 0.75) antigens. These results are interpreted as indicating that the size of PNH clone is better assessed by immunophenotypic analysis of monocytes and granulocytes rather than of lymphocytes and erythrocytes.

Detection of platelet-associated immunoglobulins by flow cytometry for the diagnosis of immune thrombocytopenia: a prospective study and critical review.

BACKGROUND AND OBJECTIVE: Flow cytometry (FC) to identify platelet-associated (PA) immunoglobulin (Ig) is a potentially useful diagnostic test for idiopathic thrombocytopenic purpura (ITP). However, the restricted application of PAIg measurement to thrombocytopenic populations primarily comprised of ITP patients will artificially enhance the test's diagnostic specificity. For this reason, we performed a prospective study in which the results of a sensitive technique for detecting PAIg, as is FC, were correlated to the cause of the thrombocytopenia. DESIGN AND METHODS: A total of 118 patients with platelet counts <100 x 10(9)/L and 30 normal donors with a platelet count >200 x 10(9)/L were studied for PAIg employing a flow cytometer. Forty-two children and 20 adults were diagnosed as having immune thrombocytopenia and 27 children and 29 adults had nonimmune thrombocytopenia of different etiology. RESULTS: Raised levels of PAIg were found in 56/62 patients with immune thrombocytopenia and in 34/56 patients with non-immune thrombocytopenia. Diagnostic values of PAIg for the detection of immune thrombocytopenia were: sensitivity 90.3% and specificity 39. 3%. An enzyme-linked immunoabsorbant assay (ELISA) for the detection of autoantibodies to platelet glycoprotein (GP) complexes was used in adults, 9 with immune-related thrombocytopenia and 16 with non-immune thrombocytopenia, in order to determine the true non-specific nature of the positive PAIg test. By ELISA, 8/9 patients with immune thrombocytopenia and 7/16 with non-immune thrombocytopenic disorders showed autoantibodies to platelet GP complexes. INTERPRETATION AND CONCLUSIONS: PAIg detection by FC constitutes a sensitive but non-specific assay thus making it unnecessary and inappropriate for establishing the diagnosis of ITP.

[Classification of acute leukemias according to the first latin-american consensus conference for the immunophenotyping of leukemias]. / Clasificación de las leucemias agudas de acuerdo con el consenso de la primera conferencia latinoamericana en la tipificación inmunológica de las leucemias.

OBJECTIVE: To evaluate the recommendations of the First Latinamerican Consensus Conference for the Immunophenotyping of Acute Leukemia in untreated patients with de novo disease immunologically classified employing flow cytometry and an extended panel of monoclonal antibodies. MATERIAL AND METHODS: In that conference it was recommended the use of the following antibodies: cytoplasmic CD79a (cCD79a) and CD19 to define B-progenitor acute lymphoblastic leukemia (B-ALL); cCD3 and CD7 for T-cell ALL (T-ALL), and CD13, CD33 and myeloperoxidase (cMPO) for acute myeloblastic leukemia (AML). We analyzed the expression of these cellular antigens in 91 non-consecutive patients classified with the extended panel as: B-ALL 28 cases; T-ALL 7; B-T-ALL 2; AML 47; and mixed-lineage acute leukemia 7 cases. RESULTS: All 28 B-ALL cases were positive with each of the two recommended antibodies cCD79a and CD19, whereas in 24 AML cases (the expression of cCD79a was not assayed in 23 cases) and in 7 T-ALL patients both antigens were absent. cCD3 and CD7 antigens were identified in 71% and 100% of T-ALL, respectively. CD7 antigen was not detected in any of the 28 patients with B-ALL but it was expressed in 6 of 47 AML cases, while none of 75 B-ALL and AML cases were positive to cCD3. Forty nine percent of AML were positive for the three recommended markers: cMPO, CD13 and CD33, and 51% of AML cases reacted with one or two of these three monoclonal antibodies. Six out of 28 cases of B-ALL had aberrant expression of myeloid antigen (CD33 in 3 cases and CD13 in 3 cases). CONCLUSIONS: There was no difference in the definition of AL lineage between employing the extended antibody panel and that recommended by the Latinamerican consensus.

Light scatter and immunophenotypic characteristics of blast cells in typical acute promyelocytic leukemia and its variant.

Acute promyelocytic leukemia (APL), defined by the French-American-British (FAB) classification as the M3 subtype of acute myeloblastic leukemia (AML), is readily diagnosed by direct cytomorphologic examination. The potential difficulty in recognizing the microgranular variant of APL (M3v) stems from the morphological characteristics of APL leukemic cells, which resemble monocytes. From 109 newly diagnosed acute leukemic patients, 48 were classified as AML and 16 of these patients (33%) had APL Mononuclear cells (MNC) of all APL patients were analyzed by flow cytometry for immunophenotypic features and forward and right angle scatter (FW-SC/RT-SC) light characteristics. Two clearly different FW-SC/RT-SC distribution patterns were recognized and defined as hypergranular (mature cells) and hypogranular (immature cells). Correlation between FW-SC/RT-SC patterns and the FAB system was poor: from eight patients classified as M3, six had the hypergranular pattern and two had the hypogranular pattern; from eight cases with M3, five and three patients had hypogranular and hypergranular patterns, respectively. The most relevant cellular immunophenotypic feature was the high frequency of CD34+ cases (5/7) recorded exclusively in patients with the hypogranular pattern. An interesting finding was that MNCs of all APL patients changed color from beige to green in the course of 3-4 h, whereas none of the 93 specimens of non-M3 acute leukemia cases showed this phenomenon. Summarizing, the FW-SC/RT-SC characteristics of APL blast cells along with the immunophenotype may represent an objective and reproducible measurement system to distinguish microgranular (M3v) from typical (M3) APL In addition, the present study has identified another unique feature of APL based on the green color of their blast cells imparted by the high content in myeloperoxidase.

[Anemia and iron deficiency in 490 Mexican pregnant women]. / Anemia y deficiencia de hierro en 490 embarazadas mexicanas.

OBJECTIVE: To explore correlations of sociobiological variables with levels of blood hemoglobin (HB) in 490 pregnant women. SETTING: Women attending private practice and two public hospitals in the city of Leon, State of Guanajuato (1800 m above sea level). MATERIAL AND METHODS: Demographic, obstetric, nutritional and socioeconomic data were obtained together with an EDTA-blood sample for CBC, and serum for metabolite assays. The women had a mean gestation of 25 weeks (range 4-40) and 65% were multiparous with a mean parity of 2.1. By Mexican standards they had fairly high social, nutritional and intergenesic lapse. Associations were explored by step-wise multiple ANOVA. RESULTS: On the basis of HB < 12 g/dL (equivalent aprox to 11 at sea level), 37% of the women were considered anemic. The MANOVA (excluding iron deficiency) showed associations of HB with gestation (p < 0.001) and parity (p = 0.024). Iron deficiency was present in 76% of the anemics (136/180) and 31% of the non-anemics (97/310). Folate and vitamin B12 assays in women with anemia and no iron deficiency showed folate or B12 deficiency in only 33% (14/43) leaving 29 cases with anemia of unknown etiology. CONCLUSIONS: 1. Gestation age was the factor most strongly associated to anemia and iron deficiency in our sample. 2. Anemia and iron deficiency were seen in 37% (N = 180) and 48% (N = 233) of the women respectively. 3. Of the 180 anemic women, 76% (N = 136) were iron deficient but only 14/43 anemic without iron deficiency were folate or B12 deficient leaving 6% (29/490) with anemia of unknown etiology. 4. The prevalence of anemia and iron deficiency were high in our population in spite of its fairly good sociodemographic and nutritional conditions.

Effect of androgen therapy and anemia on serum erythropoietin levels in patients with aplastic anemia and myelodysplastic syndromes.

Immunoreactive serum erythropoietin (EPO) was measured in anemic and non-anemic patients with acquired non-severe aplastic anemia (AA; n = 22) and myelodysplastic syndromes (MDS; n = 31) receiving or not androgens to examine the effect of androgen therapy and anemia on EPO levels in these disorders. Soluble transferrin receptor (TfR) and absolute reticulocyte count (ARC) were also assayed in order to evaluate erythropoietic activity. AA and MDS patients were stratified for anemia and androgen treatment as follows: 12 untreated anemic patients; 17 anemic patients during androgen therapy; 14 non-anemic patients without any treatment (> 1 year); and 10 non-anemic patients on androgen therapy. Although EPO levels in non-anemic patients were significantly higher than in healthy controls (n = 29) no statistically significant differences in Hb and EPO values were found between non-anemic patients receiving or not androgen therapy. In the linear regression analysis between Hb and log EPO concentration, no statistically significant differences in the slopes between untreated and androgen-treated anemic groups nor between both groups and patients with iron deficiency anemia (n = 23) were observed. However, the y intercept (log EPO) of regression line was significantly higher in androgen-treated anemic patients than in the androgen therapy-free anemic group. Serum TfR levels were higher in treated than in untreated anemic patients, whereas ARC was not different between both groups. These data seemingly indicate that (1) androgens at pharmacological doses do not increase serum EPO levels in non-anemic AA and MDS patients, and (2) in patients with AA and MDS, androgen-driven EPO stimulation is appreciably enhanced by anemia.

Circulating lymphocyte subpopulations and activated T and B cells in patients with chagasic and non-chagasic myocardiopathy.

Trypanosoma cruzi causes a profound immune depression in the infected host, and a small proportion of chagasic patients will develop a chronic disease characterized by myocardiopathy. There is evidence suggesting that dilated non-chagasic cardiomyopathy may be mediated by an immunological mechanism. In an attempt to distinguish abnormal immunoregulatory cell patterns in both dilated myocardiopathies, total and activated T and B lymphocyte subpopulations were measured by flow cytometry and double-labeling in whole blood samples from patients with dilated myocardiopathy, 10 with positive serological tests for T. cruzi and 9 with different non-chagasic cardiomyopathies. Several significant differences were found between both groups of patients and 13 sex- and age-matched apparently healthy controls. Chagasic patients besides showing clear decrease in absolute numbers of CD3+/CD71+ and CD8+/CD25+ cell populations also had a significant increase in CD19+, CD10+, and CD19+/HLA-DR+ cell subsets, as well as high helper/ suppressor cell ratio. These findings suggest that concurrently with T cell diminution, which involved activated T lymphocytes displaying suppressor/cytotoxic immunophenotype, chronic chagasic patients with myocardiopathy showed elevated numbers of total and activated B lymphocytes. Patients with dilated non-chagasic myocardiopathy had significantly increased numbers of activated T cells (CD3+/CD25+, CD8+/CD25+, and CD8+/HLA-DR+) and total and activated B lymphocytes (CD10+, CD19+, CD19+HLA-DR+). These data support the notion that dilated myocardiopathies other than the chagasics may be associated with immunological abnormalities.

[Penetrating trauma by foreign body in the left heart ventricle]. / Traumatismo penetrante con cuerpo extraño en el ventrículo izquierdo.

We present the case of a patient who suffered a cardiac penetrating trauma due to a 6-cm long steel splinter. He was self-admitted to the emergency room and was asymptomatic. Cardiac trauma was diagnosed by the presence of a foreign body in his chest X-ray. Transthoracic and transesophageal echocardiography showed pericardial effusion and a dense foreign body that crossed the left ventricle from upside down and forward to back. The patient underwent cardiac surgery under extracorporal circulation. A shooting wound was seen on the left ventricular free wall. Transesophageal echocardiography was performed during surgery in order to define the position of the foreign body and to discard lesions due to multidirectional injury. Lesions were repaired and the patient was discharged with no complications. This case report illustrates the possibility of survival after cardiac penetrating trauma, and the role of echocardiography in the diagnosis and surgical repair of this type of trauma.

Immunophenotypic characteristics of the blast crisis in chronic myeloid leukemia.

OBJECTIVE: To characterize the immunophenotype of blast crisis (BC) in Mexican patients with chronic myeloid leukemia (CML). MATERIAL AND METHODS: Mononuclear cells of 17 patients with CML in BC were immunophenotyped employing a panel of 18 monoclonal antibodies: CD5, CD10, CD14, CD22, and anti-HLA-DR used in all patients; CD2, CD15, CD19, CD34, and CD41 in 13 to 16 patients; and CD3, CD7, CD13, CD20, CD21, CD33, CD42b, and CD61 in less than 10 patients. RESULTS: Myeloid was the most frequent type (9/17 cases) followed by lymphoid (6/17) and hybrid or mixed lineage (2/17). Four of the myeloid BC expressed megakaryocyte/platelet associated antigens; 5 of 6 cases with lymphoid BC showed an early precursor B cell immunophenotype (HLA-DR+, CD10+), and the other was an uncommon case of lymphoid B/T transformation (CD19+, CD5+). The CD34 antigen was present in 6 out of 15 cases: 4 patients with lymphoid BC, 1 with myeloid transformation, and 1 with megakaryoblastic BC. CONCLUSIONS: Our findings are comparable to those found in the literature comprising 192 patients. The present study confirms the lineage heterogeneity of CML BC and suggests that extensive immunophenotyping may allow insight for a more precise recognition of normal and leukemic ontogenesis.

[Cellular immunophenotypes in 97 adults with acute leukemia]. / Inmunofenotipos celulares en 97 adultos con leucemia aguda.

OBJECTIVE: To analyze hematopoietic cell surface antigen reactivity in acute leukemia (AL) by flow cytometry and identify acute mixed-lineage leukemias (AMLL) employing the most widely accepted criteria. MATERIAL AND METHODS: Ninety seven patients with de novo AL were studied. Cell surface antigens were investigated with monoclonal antibodies directed to: B lymphoid (CD10, CD19, CD20, CD21, CD22); T lymphoid (CD2, CD3, CD5, CD7); and myeloid (CD13, CD14, CD15, CD33, CD41) cell lineages. Maturation cell-associated antigens (CD34, HLA-DR and TdT) were also studied. RESULTS: Twelve patients unclassified by cytomorphology could be classified by immunophenotype. Using cytomorphologic, cytochemical and immunophenotypic data, 54 cases corresponded to acute lymphoblastic leukemia (ALL) and 43 were acute myeloblastic leukemia (AML). In All there were 63% B lineage, 15% T, 7% T/B, 6% undifferentiated and 9% mixed-lineage (coexpression of two or more myeloid-associated antigens). In AML, myeloid immunophenotype was observed in 86% undifferentiated in 2%, and mixed-lineage in 12% (coexpression of two or more lymphoid-associated antigens). In addition, 26% of ALL cases and 12% of AML cases expressed a single myeloid and lymphoid antigen respectively. The most common aberrant antigens in ALL and AML were CD13 and CD7 respectively. The highest frequency of CD34 antigen expression (90%) was detected in patients with AMLL. CONCLUSIONS: Flow cytometric immunophenotypic analysis allowed to: a) establish diagnosis in cytomorphologically unclassified cases; b) identify AMLL with a frequency similar to that reported in other series; and c) confirm the heterogeneity of AL.

Circulating colony-forming units of granulocytes/monocytes in patients with chronic myeloid leukemia before and during busulfan treatment.

The number of colony-forming units of granulocytes/monocytes (CFU-GM) in the peripheral blood of 7 patients with chronic myeloid leukemia (CML) in chronic phase (CP) receiving standard doses of busulfan (BSF, 0.1-0.2 mg/kg/day p.o.) was compared to that found in 8 patients with CML in CP not previously treated in order to establish if non-myeloablative chemotherapy mobilizes committed granulomonocytic progenitor cells into the circulation. The number (mean +/- SEM) of spontaneous CFU-GM in untreated patients was similar to that recorded in 10 sex- and age-matched controls, 2.6 +/- 1.9 and 3.5 +/- 2.1, respectively. BSF-treated patients showed significantly more spontaneous CFU-GM (13.9 +/- 7.5) than controls and untreated patients. Addition of recombinant human granulocyte/monocyte colony-stimulating factor to cultures promoted colony growth in controls but not in untreated and BSF-treated patients. These data seemingly indicate that: 1) administration of standard non-myeloablative doses of BSF to patients with CML in CP mobilizes CFU-GM into the circulation and 2) BSF therapy selects a granulomonocytic colony-forming progenitor cell population with increased autonomous growth potential. These findings may contribute to the understanding of the therapeutic role of BSF in CML.

Red blood cell indices in a high altitude hospital population.

It is currently accepted that the red blood cell indices (MCV, MCH and MCHC) are the same in general care hospital populations throughout the world. The aim of the study was to explore whether the internationally accepted values for red cell indices are the same in a hospital located in Mexico City at 2240 meters above sea level (7352 feet). The setting for the study was a third level specialized care hospital for adults with chronic degenerative problems (trauma and obstetric cases were not seen). Each day, for a period of 139 working days, 120 EDTA blood samples of patients were assayed within 3h of extraction in a flow cytometer analyzer (Coulter STKR). Using the moving average approach of Bull (Reference 3) in batches of 20 samples, a raw daily value for each indice was obtained with the mean of the six daily moving averages. The daily raw value was multiplied by a ratio (assigned/observed ratio) of the corresponding daily value obtained in a normal preserved blood control (Coulter's 4C): we refer to them as corrected values in this paper. A total of seven batches of the Coulter control were used to obtain the corrected values during the 139 days of observation. The results were as follows. The mean (SD) of correction values in the 139 days were: MCV = 90.33 (.810) fl, MCH = 30.75 (.582) pg, MCHC = 33.38 (.630) g/dl. The indices showed significant changes in mean as a function of batch of the Coulter control used (F tests, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular and humoral immune parameters in women with pathological hyperprolactinemia before and during treatment with bromocriptine.

PROBLEM: Experimental and clinical evidence has suggested an immunostimulatory effect of prolactin and that bromocriptine, an inhibitor of prolactin release, counteracts the actions of prolactin on the immune system. The aim of this study was to determine the impact of elevated serum prolactin levels on the immune system in patients with pathological hyperprolactinemia. METHOD: For this purpose, parameters of the cellular and humoral immune system were studied in six women with prolactinomas and one with idiopathic hyperprolactinemia. Studies were performed when serum prolactin concentrations were high as well as during different phases of the menstrual cycle when prolactin levels had been normalized through treatment with bromocriptine. RESULTS: Hyperprolactinemic subjects, when compared with six age-matched normal women, had significantly higher percentages of total lymphocytes and CD2+ cells. Elevation of CD4+ cells was also observed although to a lesser extent. Bromocriptine-treated patients, when compared with normal women were characterized by increased numbers of total lymphocytes and CD4+ cells, decreased percentage of CD8+ cells, and increased concentrations of serum IgM. These last two findings were also significantly different when compared to those observed in hyperprolactinemia. CONCLUSION: In this study we have described the changes on cellular and immune parameters in patients with hyperprolactinemia before and during bromocriptine therapy, which support the links of communications between the immune and endocrine systems in humans.

Clinical usefulness of mean corpuscular volume and red cell distribution width in iron deficient blood donors.

The clinical efficacy of the red cell distribution width (RDW > 14.2%) and the mean corpuscular volume (MCV < 83.5 fL) in detecting iron deficiency was evaluated in female blood donors. Employing transferrin saturation < 17%, the prevalence of iron deficiency in 296 female donors was 23%, and in 635 male donors 1.1%. In the total female population, the sensitivity and specificity of the indices were 78% and 92%, respectively, but they were higher in anemic females (sensitivity 90% and positive predictive value 92%) than in non anemic females (sensitivity 58% and positive predictive value 50%). Our results confirm that there is an overlap in the levels of RDW and MCV between the iron and non iron deficient subjects, and these overlap seems to be more remarkable in the non anemic individuals. We conclude that these erythrocyte indices could be useful to identify iron deficiency in anemic female blood donors, but not in non anemic ones.

Peripheral blood lymphocyte subsets and serum immunoglobulins in Sheehan's syndrome and in normal women during the menstrual cycle.

OBJECTIVE: There has been increasing evidence on the mechanisms underlying the interactions between the neuroendocrine and the immune systems, particularly in animal models with relatively few information in the human. In this study, we evaluate the cellular and humoral immunity in female patients with hypopituitarism and in normal women throughout the menstrual cycle in an attempt to determine the role of pituitary and gonadal hormones on the immune system. DESIGN: Serum immunoglobulins, peripheral blood lymphocyte subsets, and serum hormones were measured in eight patients with postpartum pituitary necrosis (Sheehan's syndrome) and in six normal women along different phases of the menstrual cycle, taking advantage of the lack of pituitary function and the cyclic variations in serum hormones, respectively. RESULTS: Patients with Sheehan's syndrome had higher T lymphocytes (CD2), including helper (CD4) and suppressor (CD8) cell subpopulations and B lymphocytes (CD19) when compared with normal menstruating women. An increase of serum IgA concentrations was also observed. Normal women showed little non-statistically different changes along the menstrual cycle in peripheral blood cell parameters and in serum immunoglobulin levels. CONCLUSIONS: a) Hypopituitarism in humans, in contrast with the animal model, may associate with immune up-regulation at both cellular and humoral levels; and b) hormonal changes along the normal menstrual cycle probably do not influence in great extent the immune system.