Osmotic fragility of peripheral blood lymphocytes in chronic lymphatic leukemia and malignant lymphoma

The osmotic fragility (OF) of peripheral blood lymphocytes from patients with chronic lymphatic leukemia (CLL) and non-Hodgkin malignant lymphoma (ML) was investigated employing an automatic recording method and compared with that of lymphocytes from healthy subjects and from patients suffering from various non-neoplastic diseases. The curves from CLL and ML showed a pattern of increased lymphocyte OF compared with those of the two control groups, and the difference was statistically significant ( less than 0.001). In CLL the increase in OF was more pronounced than in ML, and the shape of the curve was different from that in the other groups. The employment of peripheral blood lymphocyte OF as an additional diagnostic parameter in the diagnosis of CLL and ML is suggested.     

Osmotic fragility of human blood platelets

The osmotic fragility of 50 samples of platelets from normal healthy donorshas been studied. It has been found that fragility of platelets starts at a concentration of about 0.44 per cent NaCl and is complete at a concentration of0.34 per cent. The serotonine released from the platelets increased with thegradual disintegration as the saline concentration fell.

Submitted on February 7, 1956 Accepted on February 17, 1956     

Mobilization kinetics of peripheral blood progenitor cells after IAPVP-16 salvage chemotherapy plus G-CSF in lymphoproliferative disorders

We have explored the efficacy of salvage chemotherapy combination, IAPVP-16 (ifosfamide 5 g/m2 on day 1; VP-16 100 mg/m2 on days 1-3; ara-C 1.2 g/m2/12 h on days 1 and 2; methylprednisolone 80 mg/m2 on days 1-5) plus G-CSF for PBPC mobilization. This protocol was used in 45 patients with relapsed or refractory lymphoproliferative diseases who underwent 85 leukaphereses. In 41 patients > 2 x 106/kg CD34+ cells were obtained after a median of two procedures. The median number of CD34+ cells harvested was 3.2 x 106/kg per apheresis and 8.4 x 106/kg per patient. Seven of 10 patients who had failed previous mobilization attempts achieved more than 2 x 106 CD34+ cells/kg in a maximum of three aphereses. A history of previous mobilization failure and a low platelet count (<150 x 109/l) negatively influenced the CD34+ cell yield in univariate and multivariate analyses. A good correlation was found between the circulating CD34+ cells/microl and the CD34+ cells and CFU-GM in the leukaphereses products (r = 0.93 and r = 0.73, P < 0.001), and > or =17 CD34+ cells/microl predicted the achievement of > 2 x 106/kg CD34+ cells in a single leukapheresis in more than 90% of cases. IAPVP-16 plus G-CSF may be specially indicated in tandem transplantations or CD34+ selection and in patients who have failed previous mobilization attempts.     

Osmotic fragility of human blood platelets: phase contrast and electron microscopic studies

Phase contrast and electron microscopic studies on the morphologic changesof platelets in various hypotonic salt solutions are presented.

Submitted on September 26, 1957 Accepted on March 6, 1958     

Expression of CD55 and CD59 on peripheral blood cells in patients with lymphoproliferative disease of granular lymphocytes

Lymphoproliferative disease of granular lymphocytes (LDGL) is a disorder characterized by the clonal expansion of granular lymphocytes. It has recently been shown that the clonal expansion of granular lymphocytes occurs in patients with paroxysmal nocturnal hemoglobinuria (PNH) in a subclinical fashion. To test the possibility that LDGL patients share a PNH phenotype, we obtained peripheral blood cells from 20 patients with LDGL and examined the expression of the glycosylphosphatidyl inositol (GPI)-anchored proteins, CD55 and CD59. Compared with normal controls, however, a defective expression of CD55/59 was not observed on either granulocytes or erythrocytes from LDGL patients. An unexpected finding was the significantly lower CD55/59 expression on granular lymphocytes from patients with CD16(+)CD56(-) phenotype LDGL than from patients with CD16(+)CD56(+) phenotype LDGL, or natural killer (NK) and NK/T lymphocytes from healthy individuals. The positive correlation between the expression of CD56 and CD55/59 might have some relevance to the functional properties of the CD56(+) subset of large granular lymphocytes.     

Total and "activated" peripheral blood T lymphocytes in patients with thyroid disorders.

The percentage of total and "activated" peripheral blood T lymphocytes was measured in patients with (i) hyperthyroid Graves' disease selected for absence of ophthalmopathy, (ii) treated Graves' disease, with ophthalmopathy, and (iii) other thyroid disorders including subacute thyroiditis, using sheep red blood cell rosette tests. No patient had significantly increased levels of either total or "activated" T lymphocytes. On the other hand, the percentage of total T cells was below normal in 8 of 18 patients with hyperthyroid Graves' disease and in 6 of 18 patients with ophthalmopathy compared with only one of 12 patients with nodular goitres. Similarly, low levels of "activated" T cells were demonstrated in 5 of 18 patients with hyperthyroid Graves' disease and in 10 of 18 patients with ophthalmopathy compared with only one of 12 patients with nodular goitres. Three of four patients with subacute thyroiditis tested had depressed levels of total T lymphocytes whilst only one had low levels of "activated" T lymphocytes. Levels returned to normal during the recovery phase in the two patients with positive tests who were retested. Depressed levels of T lymphocyte populations in patients with Graves' disease and subacute thyroiditis may be due to feedback suppression and/or "exhaustion" in association with the thyroidal and orbital immunological reactions.     

Angiogenesis in lymphoproliferative disorders

In this review, the cellular and molecular mechanisms underlying angiogenesis in lymphoproliferative disorders are summarized, alongside with possible therapeutic applications. Although most of the initial studies in angiogenesis were done on solid tumors, recent data demonstrate the importance of angiogenesis in hematological malignancies including leukemia, lymphoma, and multiple myeloma. Expression of angiogenic polypeptides vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) correlate with clinical characteristics in leukemia and lymphoma, and their serum concentrations serve as predictors of poor prognosis. Antiangiogenic drugs, including thalidomide, arsenic trioxide, endostatin, vasostatin, and neutralizing antibodies to VEGF receptors, used alone or in combination with established chemo- or immunotherapy regimens, constitute a promising approach for the treatment of lymphoproliferative disorders.     

The effect of smoking on peripheral blood lymphocytes and on some immunological parameters in old age

To investigate the influence of smoking on the aging immune system, the following parameters were determined in elderly smokers and non-smokers: presence of emphysema; absolute number of leucocytes, lymphocytes, T cells and B cells bearing membrane-bound IgG; serum IgG, IgA, IgM levels, occurrence of rheumatoid and antinuclear factors, and natural antibody level (against different bacteria). Ultrastructural disorders in lymphocytes were also investigated. The number of leucocytes, the levels of serum IgA, and the prevalence of autoantibodies were higher, and the natural antibody level was lower in smokers than in non-smokers. Giant mitochondria and cytoplasmic disorders were found more frequently in smokers than in non-smokers, and in an even higher rate in smokers with emphysema. These findings suggest that smoking may accelerate the appearance of age-dependent (especially disease-related) immunological changes.     

Direct correlation between the load of Epstein-Barr virus-infected lymphocytes in the peripheral blood of pediatric transplant patients and risk of lymphoproliferative disease

The Epstein-Barr virus (EBV) is known to cause posttransplant lymphoproliferative disease (PTLD) in immunosuppressed transplant patients. The results of this pilot study showed that all EBV- patients pretransplant experienced primary EBV infection within the first 3 months after transplant surgery. Virtually all of these patients had a higher burden of EBV-infected cells in their peripheral blood (PB) after infection by EBV than did the EBV+ pretransplant group when tested at the same intervals posttransplant. Salivary EBV titers also increased in most patients, but the difference between the two groups was statistically significant only at 12 months, whereupon EBV+ patients showed higher titers compared with EBV- (alpha < 0.053). Also, polymerase chain reaction amplification followed by Southern blotting was performed to detect EBV sequences in PB mononuclear cells. This technique allowed confirmation of the blood culture results and constituted a faster alternative compared with the culture assay. The highest increase in the number of EBV-infected lymphocytes at 3 months posttransplant obtained from PB was seen in a patient who developed fatal PTLD and in another with protracted infectious mononucleosis. Thus, the number of EBV-infected cells in PB was found to correlate positively with risk of development of PTLD at 3 months posttransplant in our group of pediatric transplant patients. This study showed that quantitative lymphocyte culture of PB was an accurate index of immunosuppression and a reliable method for assessing the risk of PTLD development.     

Alemtuzumab in T-cell lymphoproliferative disorders

The humanized monoclonal antibody alemtuzumab binds to the CD52 antigen, a glycoprotein which is widely expressed on normal and malignant B and T lymphocytes. Recently it has been demonstrated in a number of clinical trials that alemtuzumab has clinical activity in mature T-cell diseases such as T-prolymphocytic leukaemia and cutaneous T-cell lymphoma, inducing responses in up to two thirds of heavily pre-treated relapsed/refractory patients. Response was associated with improved survival. The toxicity profile for the antibody is manageable. The major complications are infusional reactions associated with initial injections, and prolonged lymphopenia associated with reactivation of viruses. Future studies will be directed towards alternative (subcutaneous) routes and schedules of administration, use as first-line therapy, combination strategies, and role of alemtuzumab to purge minimal residual bone-marrow disease prior to stem-cell transplantation.     

Cord blood T lymphocytes lack constitutive perforin expression in contrast to adult peripheral blood T lymphocytes

Perforin is the cytolytic pore-forming protein, which alone can be responsible for the lethal hit in one of the killing mechanisms used by natural killer (NK) cells or cytotoxic T lymphocytes. In this study, perforin expression was investigated in cord blood (CB) lymphocytes to determine their killing potential in vivo. The majority of CB CD3- NK cells had the protein. Compared with adult perforin-positive NK cells, a significantly lower percentage of cells expressing CD56 and CD57, the related neural cell adhesion molecules, was found (P = .0001). Perforin was also present in a unique immature CB NK-cell subset, characterized by cytoplasmic CD3 antigen (Ag) expression. In CB, very few CD8 perforin-positive T lymphocytes could be detected, but they were in significant numbers in adult peripheral blood (P = .02). A substantial proportion of these cells (70% +/- 23%) lacked the CD28 T-cell coactivation Ag, and they were able to exert NK-like, major histocompatibility complex nonrestricted cytolytic activity. CD4+ and gamma delta-T cells expressing perforin were absent from CB, but low numbers of such cells were detected in adult peripheral blood (P = .0001). Therefore, the spontaneous cytolytic activity of CB lymphocytes appeared to be dependent on well-represented perforin-positive NK cells, which were shown to efficiently lyse NK-sensitive target cells.