The lymphocyte cytochemical equipment and serum immunoglobulins in patients with precancerous states of the larynx.

In 24 men with precancerous states of the larynx, i.e. leukoplakia, papillomas and pachydermia, the peripheral blood lymphocytes were cytochemically stained for N-acetyl-beta-glucosaminidase, beta-glucuronidase, acid phosphatase and glycogen (PAS reaction). The results were expressed in terms of the absolute counts of enzyme- (or compound-) positive cells. The serum immunoglobulin IgG, IgA and IgM levels were also determined by Mancini's method. The results obtained were compared with those in 20 healthy men aged 20 to 30 years. It was found that the patients exhibited elevated numbers of N-acetyl-beta-glucosaminidase- and beta-glucuronidase-positive lymphocytes. A characteristic feature was an increase in the absolute counts of lymphocytes with diffuse and granular-diffuse types of cytochemical reaction for all enzymes studied. The number of cells with the granular type of enzymatic reaction (intact enzyme-positive lysosomes) was significantly diminished. These cytochemical alterations were accompanied by a significant increase in the serum IgA level. These results are discussed with reference to the lymphoid system response to tissues with precancerous lesions of the larynx.     

Effect of radiotherapy on the neutrophil and the lymphocyte enzymatic equipment and serum immunoglobulins in patients with cancer of the larynx.

In 30 patients with cancer of the larynx, aged 40 to 70 years, treated by radiotherapy 6 to 9 years ago the decreased activity of neutrophil beta-glucuronidase and N-acetyl-beta-glucosaminidase accompanied by a decrease of absolute count of enzyme-positive cells was noted. Numbers of acid phosphatase-positive neutrophils were also decreased. Moderate increase of the neutrophil alkaline phosphatase activity and of numbers of enzyme-positive cells was another observed feature. The main finding in lymphocytes of the patients consisted in the appearance of cells exhibiting diffusion of lysosomal enzymes, especially of beta-glucuronidase, N-acetyl-beta-glucosaminidase and to a lesser degree of acid phosphatase into the cell cytoplasm. Moderate increase of immunoglobulin level, especially that of IgA, reflected probably the immunologic mobilization of patients.     

Intracellular enzymatic response of lymphocytes and neutrophils in patients with cancer of the larynx.

In 20 men, aged 35 to 55 years, with untreated cancer of the larynx activity of lysosomal acid phosphatase (AP), beta-glucuronidase (GR) and N-acetyl-beta-glucosaminidase was determined cytochemically in peripheral blood lymphocytes and neutrophils by means of Barka and Anderson, Hayashi et al. and Hayashi's method, respectively; the results obtained were compared with those in 20 healthy men aged 20 to 30 years. Total count of GR-positive lymphocytes was higher in the patients than in normal persons. Total counts of AP-, GR-, and GS-positive lymphocytes with not disrupted enzyme-positive lysosomal granules within the cell cytoplasm were significantly lower and total counts of cells exhibiting the disruption of lysosomal granules and the diffuse type of cytochemical reaction were significantly higher in the patients when compared with the control group. The response of neutrophils consisted of a significant elevation in numbers of AP-, and GS-positive cells; overall score of enzyme activity studied in neutrophils was not altered in the patients. The authors disucss the significance of their observations in the light of data on participation of lymphocytic and neutrophilic lysosomal apparatus in the immunological response against tumour specific antigen in patients with cancer.     

Leucine aminopeptidase of neutrophils and lymphocytes in patients with cancer

The leucine aminopeptidase activity has been determined by using the cytochemical method of Burston and Folk in peripheral blood neutrophils and lymphocytes of 45 patients with various malignancies. Lung cancer, carcinoma of the stomach and cancer of the colon was diagnosed in 24, 16, and 5 patients, respectively. Patients with metastases showed a significantly higher activity of the enzyme if compared with that in the control group of healthy subjects and patients without metastases. The percentage of enzyme-positive lymphocytes was elevated significantly in patients with metastases whereas a total percentage of lymphocytes with regard to differential leukocyte count was diminished both in patients with and without metastases. The absolute count of neutrophils was elevated both in patients with and without metastases. The authors discuss the significance of their observation with regard to the antitumor cytotoxic effect of neutrophils and lymphocytes.     

Activity of some lysosomal enzymes in peripheral blood lymphocytes of patients with lung cancer. A cytochemical study

In 33 patients with lung cancer (6 women and 27 men, aged at average 61.2 years) the activity and intracellular localization of acid phosphatase, beta-glucuronidase and N-acetyl-beta-glucosaminidase in peripheral blood lymphocytes were determined by means of semiquantitative cytochemical methods. In comparison to the control group of healthy subjects, the patients with lung cancer showed increased counts of acid phosphatase-positive lymphocytes with granular-diffuse cytochemical reaction, increased counts of beta-glucuronidase-positive lymphocytes with solely granular type of reaction and increased numbers of N-acetyl-beta-glucosaminidase-positive cells showing the granular, granular-diffuse and diffuse type of reaction. The total count of beta-glucuronidase-positive and N-acetyl-beta-glucosaminidase-positive lymphocytes was significantly elevated in these patients. The authors discuss the significance of their observations for evaluating lymphocyte response in patients with lung cancer.     

Lysosomal enzymes in peripheral blood lymphocytes of patients with gastric cancer

The activity of acid phosphatase, beta-glucuronidase and N-acetyl-beta-glucosaminidase was assessed using semiquantitative cytochemical methods in peripheral blood lymphocytes of 45 untreated patients with gastric cancer and 80 healthy subjects. In cancer patients the study demonstrated a statistically significant decrease in the number of lymphocytes with granular reaction for acid phosphatase and N-acetyl-beta-glucosaminidase, as well as an increase in the number of lymphocytes showing a granular-diffuse reaction for the above enzymes and a diffuse reaction for all the studied lysosomal enzymes. Possible mechanisms of the observed changes are discussed.     

Large granular lymphocytes,Leu 7 reactivity and natural killer cell function in peripheral blood of patients with Hodgkin's disease

Summary The percentage and absolute number of lymphocytes and Leu 7⁺ cells were significantly lower in HD even in active stages. There was no significant difference in the percentage of LGL between the three groups (control, active HD, inactive HD), however, because of differences in counts of lymphocytes the absolute number of LGL was significantly lower in HD even in the active group than that in healthy controls. The absolute count of LGL and Leu 7⁺ cells in patients in remission was significantly higher than that in active HD. Natural cytotoxicity against K-562 cells was also significantly lower in active patients in comparison with controls, while the percentage of cytotoxicity was slightly but not significantly higher in patients in remission than that in the active group. A positive correlation was observed between all the three examined parameters both in controls and in patients with active and inactive HD.     

Semiquantitative cytochemical determination of acid phosphatase, beta-glucuronidase, and beta-glucosaminidase activity in peripheral blood lymphocytes.

Activity of acid phosphatase, beta-glucuronidase, and beta-glucosaminidase in peripheral blood lymphocytes was determined cytochemically in 20 normal subjects, 10 male and 10 female, by the use of BARKA and ANDERSON's (1962), HAYASHI et al. (1964) and HAYASHI's (1965) methods, respectively. Results obtained were semiquantitatively according to subdivision of lymphocytes into enzyme-negative and enzyme-positive cells. Enzyme-positive lymphocytes were divided into cells with granular, mixed granular and diffuse enzymatic reaction type. In the first two types of cytochemical reaction a number of enzyme-positive lysosomal granules were counted and expressed in terms of both absolute count and percentage of circulating lymphocytes. Enzyme-positive lymphocytes represented 80.3%, 40.5% and 41.5% of the total lymphocyte count in regard to the presence of acid phosphatase, beta-glucuronidase, and beta-glucosaminidase, respectively.     

Efficacy of cancer chemotherapy in relation to the pretreatment number of lymphocytes in patients with metastatic solid tumors

The evidence of lymphocytopenia has been demonstrated to predict a poor prognosis in terms of survival in advanced cancer patients. This finding is not surprising because of the fundamental role of lymphocytes in mediating tumor cell destruction. Despite the importance of lymphocytes in the pathogenesis of cancer, there are only few data about the profile and the function of lymphocytes during the various antitumor therapies, and in particular the relation between lymphocyte pretreatment number and response to chemotherapy remains to be established. The present study was performed to evaluate whether the evidence of lymphocytopenia before the onset of treatment may influence the efficacy of chemotherapy in metastatic cancer patients affected by the most frequent tumor types. The study included 183 patients (lung cancer: 89; colorectal cancer: 63; breast cancer: 31), 95 of whom had been previously treated with chemotherapy. The chemotherapeutic regimens consisted of oxaliplatin plus 5-fluorouracil and folates in untreated colorectal cancer, weekly irinotecan in pretreated colorectal cancer, cisplatin plus gemcitabine or etoposide in untreated lung cancer, weekly vinorelbine in pretreated lung cancer, and taxotere in breast cancer patients who had been previously treated with anthracyclines. Lymphocyte count was considered to be abnormally low for values below 1500/mm3. Lymphocytopenia was found in 79/183 (43%) patients, without any significant differences in relation to tumor histology. A complete response (CR) was achieved in 6/104 patients with a normal lymphocyte count and in none of the 79 lymphocytopenic patients. A partial response (PR) was obtained in 39 patients with a normal lymphocyte count and in only eight patients with a low lymphocyte count prior to therapy. Therefore, irrespective of the type of chemotherapy, the objective tumor response rate (CR + PR) in lymphocytopenic patients was significantly lower than in patients with normal pretreatment lymphocyte counts (8/79 vs 45/104; p < 0.001). This study shows that the evidence of lymphocytopenia prior to chemotherapy is associated with a lower efficacy of treatment in terms of objective tumor regression rates in patients with metastatic solid tumors, and suggests that the action of chemotherapy may depend at least in part on an interaction with the antitumor immunity. Pretreatment lymphocyte count may represent a new, simple biological marker to be taken into consideration by oncologists in the chemotherapeutic treatment of metastatic cancer.     

Influence of oral BM 12531 (INN azimexon) on immune response in untreated cancer patients

Summary To evaluate the immune-stimulating properties of 2-(2-cyanaziridinyl-[1]-)-2-(2-carbamoylaziridinyl-[1]-) propane (INN azimexon) a randomized double-blind study was performed in 30 cancer patients with different solid tumors. A group of 15 patients received 300 mg azimexon PO over a 7-day period, while 15 other patients received a placebo. We could not demonstrate an increase of total or active T lymphocytes, and the ³H-thymidine uptake of isolated lymphocytes with or without PHA stimulation was not increased when tested 3, 7, 14, and 21 days after the beginning of therapy. The serum concentration of IgM showed a slight but not significant increase, while IgG, IgA, C₃, and C₄ levels remained unchanged. The major side-effect was a significant decrease of hemoglobin and red blood cell count after azimexon administration, which was even more pronounced in four patients given 900 mg azimexon.     

The impact of lower induction values of 50 Hz external electromagnetic fields on in vitro T lymphocyte adherence capabilities

Our research thus far has concerned the impact of external electromagnetic fields (50 Hz) and low (0.01-10 mT) induction on adherence capabilities of T lymphocytes obtained from the blood of patients with head and neck tumors. We know that the in vitro adherence capability of T lymphocytes towards surfaces in cancer patients is less than that of control. Previously, we have found that exposure to electromagnetic fields (50 Hz/0.01-10 mT) increases the capability of T lymphocytes, in larynx/pharynx cancer patients, to adhere in vitro to surfaces, achieving almost physiological values, in not only pre-treatment patients but also those receiving treatment in the course of follow-up. The capability of T lymphocytes in controls (voluntary blood donors) to adhere to surfaces was also increased (50 Hz/0.01-0.5 mT). The present study concentrates on the significance of the level of electromagnetic field induction in order to determine whether low induction values can restore T lymphocytes adherence capabilities. Testing a subset of 20 patients showed a statistically significant difference (p<0.05) in the in vitro adherence capacity of T lymphocytes between both 0.01 and 0.05, and 0.1 mT induction levels. In the control group (patients diagnosed with chronic sensorineural hearing loss) there was even a statistically significant difference between induction values of 0.05 and 0.01 mT. A statistically significant difference (p<0.05) was also achieved with induction levels of 1 and 10 mT compared to 0.5, 0.1, and 0.05 mT, respectively. Therefore, we concluded that lower induction values resulted in a more biologically significant response.     

Immunologic studies in asymptomatic hemophiliac patients

Various immunological parameters were studied in 20 asymptomatic patients with hemophilia A, 3 patients with hemophilia B and 1 patient with von Willebrand disease. Patients were treated with cryoprecipitate or fresh frozen plasma. Significantly decreased mean percentage and absolute count (p less than 0.01) of peripheral blood E-rosette-forming cells compared to controls was found. There were normal mean percentages and absolute counts of lymphocytes, T-helper inducer, T-suppressor cytotoxic and natural killer cells. The proportion and absolute number of B cells was slightly increased. Significantly decreased natural killer cell activity (p = 0.02) of peripheral blood lymphocytes was observed. Our results indicate that asymptomatic patients with hemophilia may have early evidence of immunodeficiency.     

The X-ray microanalysis method for investigation of chemical composition of normal and pathologic human peripheral blood lymphocytes

The X-ray microanalysis method for investigation of chemical composition, mainly trace elements, of normal and pathologic human peripheral blood lymphocytes has been presented. The method in question consists of two stages. During the first stage the scanning electron microscope with the energy dispersive X-ray spectrometer has been used. The second stage of the method consisted of employing the above microscope with the microwave dispersive spectrometer. The method enables the short-term determination of the various elements content within the lymphocytes with particular insight into the content of elements in a single cell. The preliminary investigations showed significant differences in the content of chlorine, sulfur and lead in normal human lymphocytes and that from patients with cancer of the larynx.     

Alteration of T and null lymphocyte frequencies in the peripheral blood of human opiate addicts: in vivo evidence for opiate receptor sites on T lymphocytes

Street opiate addiction produces a significant depression in the absolute number of total T lymphocytes in peripheral blood as measured by the ability of the lymphocytes to rosette sheep red blood cells (SRBC). Associated with the decrease in T cells, there is an increase in the absolute number of null lymphocytes but no significant changes in B lymphocytes or total white blood cell count. The T cell values for 2 different populations of addicts (n = 12 and 32) are 31.8% and 23.1%, whereas the null cell values are 51.1% and 57.6%, respectively. The values for comparable control populations (n = 18 and 10) are: T% = 70.7% and 67.4%, and null % = 9.2% and 14.5%. Self-reported use of marihuana does not significantly alter the distribution of cell populations. A 1- to 3-hr incubation of addicted-derived lymphocytes with 10(-6) to 10(-7) M Naloxone reverses both T cell depression and null cell increase by allowing the null cells to express SRBC receptors. Cyclic AMP and dibutyryl cyclic AMP can also convert the null cells to T cells. The conversion of null to T lymphocytes has additionally been measured by monitoring the increase in PHA-stimulated growth in 72-hr cultures as determined by tritiated thymidine incorporation into DNA. These results support the hypothesis that opiates can alter T lymphocyte number and function in vivo, and that this alteration may produce a significant degeneration in the immune competence of street opiate addicts.     

The impact of lower induction values of 50 Hz external electromagnetic fields on in vitro T lymphocyte adherence capabilities

Our research thus far has concerned the impact of external electromagnetic fields (50 Hz) and low (0.01–10 mT) induction on adherence capabilities of T lymphocytes obtained from the blood of patients with head and neck tumors. We know that the in vitro adherence capability of T lymphocytes towards surfaces in cancer patients is less than that of control. Previously, we have found that exposure to electromagnetic fields (50 Hz/0.01–10 mT) increases the capability of T lymphocytes, in larynx/pharynx cancer patients, to adhere in vitro to surfaces, achieving almost physiological values, in not only pre-treatment patients but also those receiving treatment in the course of follow-up. The capability of T lymphocytes in controls (voluntary blood donors) to adhere to surfaces was also increased (50 Hz/0.01–0.5 mT).

The present study concentrates on the significance of the level of electromagnetic field induction in order to determine whether low induction values can restore T lymphocytes adherence capabilities.

Testing a subset of 20 patients showed a statistically significant difference (p < 0.05) in the in vitro adherence capacity of T lymphocytes between both 0.01 and 0.05, and 0.1 mT induction levels. In the control group (patients diagnosed with chronic sensorineural hearing loss) there was even a statistically significant difference between induction values of 0.05 and 0.01 mT. A statistically significant difference (p < 0.05) was also achieved with induction levels of 1 and 10 mT compared to 0.5, 0.1, and 0.05 mT, respectively. Therefore, we concluded that lower induction values resulted in a more biologically significant response.     

Effect of gemcitabine on immune cells in subjects with adenocarcinoma of the pancreas

Effects of gemcitabine (Gemzar) on immune cells were examined in pancreas cancer patients to determine whether it was immunosuppressive, or potentially could be combined with vaccines or other immunotherapy to enhance patients responses to their tumors. Blood was obtained at five time-points, before therapy, 3–4 days after initial gemcitabine infusion and immediately preceding three additional weekly infusions. Effects on T-cell subsets, B-cells, myeloid dendritic cell precursors, antigen presenting cells (APC), activated/memory, and naive cells were examined. Functional activity was measured by intracellular staining for cytokines before and after T-cell activation, and by interferon production in EliSpot responses to tumor presentation. Although absolute lymphocyte counts decreased with the initial treatment with gemcitabine infusion, the counts stabilized during subsequent treatments, then returned within normal ranges seven days after the fourth treatment so that the absolute lymphocyte count no longer differed significantly from that prior to treatment. These effects on absolute lymphocyte counts were mirrored by statistically significant decreases in absolute numbers of CD3 and CD20 lymphocytes during these time periods. The proportions of T and B-cells, however did not change significantly with therapy, although significance changes were observed in some specialized subsets. A decrease in the proportions of the major BDCA-1⁺, CD1b myeloid dendritic cell subset and a reciprocal increase in the minor BDCA-3⁺ dendritic cell subsets resulted at 3–4 days, then their levels returned to normal. No significant changes in percentages of CD86 and CD80 APCs or CD4⁺, CD25⁺T-cells were documented. Increased percentages of CD3⁺, CD45RO⁺ memory lymphocytes reached significance at day 7, then declined to statistically significant decrease at days 14 and 21 after the second and third infusions, respectively. Immune T-cells were functional in pancreas cancer patients treated with gemcitabine. The data suggest that gemcitabine therapy may decrease memory T-cells and promote naive T-cell activation. We conclude that gemcitabine therapy (1) is not immunosuppressive and (2) may enhance responses to specific vaccines or immunotherapy administered to activate or support immune responses directed toward driving effector immunity to cancer cells.     

Impaired nucleotide excision repair pathway as a possible factor in pathogenesis of head and neck cancer

Tobacco smoking is one of the major risk factors in pathogenesis of head and neck squamous cell carcinomas (HNSCC). Many of the chemical compounds present in tobacco are well-known carcinogens which form adducts with DNA. Cells remove these adducts mainly by the nucleotide excision repair pathway (NER). NER also eliminates a broad spectrum of pyrimidine dimers (CPD) and photo-products (6-4PP) induced by UV-radiation or DNA cross-links after cisplatin anti-cancer treatment. In this study DNA damage and repair was examined in peripheral blood lymphocytes obtained from 20 HNSCC patients and 20 healthy controls as well as HTB-43 larynx and SSC-25 tongue cancer cell lines. DNA repair kinetics in the examined cells after cisplatin or UV-radiation treatment were investigated using alkaline comet assay during 240min of post-treatment incubation. MTT assay was used to analyse cell viability and the Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis after treating the cells with UV-radiation at dose range from 0.5 to 60J/m(2). NER capability was assessed in vitro with cell extracts by the use of a bacterial plasmid irradiated with UV-light as a substrate for the repair. The results show that lymphocytes from HNSCC patients and HTB-43 or SSC-25 cancer cells were more sensitive to genotoxic treatment with UV-radiation and displayed impaired DNA repair. Also evidenced was a higher rate of apoptosis induction after UV-radiation treatment of lymphocytes from the HNSCC patients and the HTB-43 cancer cells than after treatment of those from healthy donors. Finally, our results showed that there was a significant decrease in NER capacity in HTB-43 or SSC-25 cancer cells as well as in peripheral blood lymphocytes of HNSCC patients compared to controls. In conclusion, we suggest that the impaired NER pathway might be a critical factor in pathogenesis of head and neck cancer.     

Effect of Beta-Adrenergic Stimulation on the Circulatory Lymphocyte Count: Studies in Normals and in Patients with Chronic Airflow Obstruction

In eight non-allergic patients with chronic airflow obstruction (CAO) and eight age and sex matched, healthy control subjects the circadian variation in circulatory lymphocyte count was studied in relation to serum Cortisol and urinary epinephrine levels. In addition, we investigated the effect of the beta-adrenergic agent terbutaline on the lymphocyte count in two ways: as a long-term effect after 8 days of oral slow-release terbutaline with constant diurnal and nocturnal serum levels in patients, and as a short-term effect by a constant rate infusion of 0.2μg/min over 4hr in normals. Both patients and controls showed similar circadian patterns of urinary epinephrine excretion and lymphocyte counts. Patients with CAO, however, had significantly lower epinephrine levels and significantly higher lymphocyte counts at all hours of observation (every 4 hr from 0800 to 0800 hr the next day), as compared with normal controls. After 8 days of slow-release terbutaline the lymphocyte count in the patient group decreased to levels not significantly different from that of normals. The circadian rhythm of the lymphocytes, however, persisted under terbutaline therapy. No correlation existed between the lymphocyte count modulating factor, serum Cortisol and the lymphocyte count over 24 hr. On placebo infusion in the control persons an increase of lymphocytes over 4hr occurred, as a consequence of circadian rhythmicity. On terbutaline infusion a significant increase of lymphocytes after 1hr was follwed by a decrease to levels significantly below those on the placebo day. The same pattern was found in the leucocyte count. From this study it is concluded that beta-adrenergic stimulation corrects the relative lymphocytosis to counts comparable with normals. Other coinciding factors must regulate, however, the circadian rhythmicity.     

Effect of Beta-Adrenergic Stimulation on the Circulatory Lymphocyte Count: Studies in Normals and in Patients with Chronic Airflow Obstruction

In eight non-allergic patients with chronic airflow obstruction (CAO) and eight age and sex matched, healthy control subjects the circadian variation in circulatory lymphocyte count was studied in relation to serum Cortisol and urinary epinephrine levels. In addition, we investigated the effect of the beta-adrenergic agent terbutaline on the lymphocyte count in two ways: as a long-term effect after 8 days of oral slow-release terbutaline with constant diurnal and nocturnal serum levels in patients, and as a short-term effect by a constant rate infusion of 0.2μg/min over 4hr in normals. Both patients and controls showed similar circadian patterns of urinary epinephrine excretion and lymphocyte counts. Patients with CAO, however, had significantly lower epinephrine levels and significantly higher lymphocyte counts at all hours of observation (every 4 hr from 0800 to 0800 hr the next day), as compared with normal controls. After 8 days of slow-release terbutaline the lymphocyte count in the patient group decreased to levels not significantly different from that of normals. The circadian rhythm of the lymphocytes, however, persisted under terbutaline therapy. No correlation existed between the lymphocyte count modulating factor, serum Cortisol and the lymphocyte count over 24 hr. On placebo infusion in the control persons an increase of lymphocytes over 4hr occurred, as a consequence of circadian rhythmicity. On terbutaline infusion a significant increase of lymphocytes after 1hr was follwed by a decrease to levels significantly below those on the placebo day. The same pattern was found in the leucocyte count. From this study it is concluded that beta-adrenergic stimulation corrects the relative lymphocytosis to counts comparable with normals. Other coinciding factors must regulate, however, the circadian rhythmicity.     

Immune status of Greek patients with beta-thalassemia major negative for anti-HIV

Patients with thalassemia who receive multiple blood transfusions are at risk for the acquired immunodeficiency syndrome. Peripheral blood lymphocyte subpopulations were studied in 22 multitransfused thalassemic patients; 10 patients were without splenectomy and 12 were studied after splenectomy. Both groups were negative for anti-HIV. Four additional patients who were found positive for anti-HIV and ten healthy controls were also included in this study. Patients without splenectomy compared to controls and to patients after splenectomy showed a significant decrease of both percentage (p less than 0.001) and absolute numbers (p less than 0.001) of Leu-7+ cells without significant abnormalities of T4/T8 ratio (1.56 +/- 0.4). Patients after splenectomy compared to controls and to patients without splenectomy showed a significant increase of the absolute numbers of lymphocytes and lymphocytes subsets T11+, T3+, T4+, T8+ and SmIg+ cells. In the seropositive patients for HIV only a significant increase of the absolute number of T8+ cells was observed while the T4/T8 ratio was 1.24 +/- 0.73. The decrease in the percentage of Leu-7+ cells in patients without splenectomy correlated inversely to the total amount of blood transfused. In conclusion patients with thalassemia had normal T4/T8 ratio and did not show the abnormal immunologic profile that has been reported in haemophiliacs.