Membrane phenotype and response to deoxycoformycin in mature T cell malignancies

The adenosine deaminase inhibitor deoxycoformycin was used in low doses to treat 19 patients with clinically aggressive T cell malignancy with a mature membrane phenotype. The patients comprised eight with prolymphocytic leukaemia, two with chronic lymphocytic leukaemia, four with adult T cell leukaemia-lymphoma, three with Sézary syndrome, and two with T cell lymphoma. Two thirds of the patients had been resistant or minimally responsive to combination chemotherapy. Complete remission was obtained in five patients (two with prolymphocytic leukaemia and one each with chronic lymphocytic leukaemia, adult T cell leukaemia-lymphoma, and Sézary syndrome) and partial remission in two others. Unmaintained complete remission lasting more than one year was seen in three patients. Responses were obtained only in patients with CD4+,CD8-membrane markers (seven out of 10), and no responses were recorded in any of the nine patients with a different phenotype. In this series remission appeared to correlate with the membrane phenotype of the neoplastic cell and not with the cytopathological diagnosis. Future studies should establish the biochemical basis for the greater sensitivity of CD4+ lymphoid cells to deoxycoformycin.     

Recombinant interleukin 2 and anti-Tac influence the growth of enriched multipotent hemopoietic progenitors: proposed hypotheses for different responses in early and late progenitors

Experiments were designed to evaluate the effect of recombinant IL-2 on growth of hemopoietic precursors from different sources (normal cord blood and bone marrow, and PB from CGL patients). For this purpose, combined cell sorting techniques and multipotent colony forming cell assays were used. A monoclonal antibody BI-3C5, which recognizes an antigen present on early lympho-myeloid cells as well as on all colony forming cells (CFU-GEMM assay), was used to enrich the studied populations. Double colour immunofluorescence techniques were performed to analyse the expression of Tac antigen on early progenitors. The results showed that rIL-2 had a stimulatory effect on growth of enriched progenitors from the three sources and surprisingly that addition of anti-Tac did not abolish this effect. On the contrary, anti-Tac enhanced even more growth of these sorted BI-3C5 precursors, suggesting a ligand action of the antibody. More interestingly, a low percentage of cord cells (1 in 1000) expressed both BI-3C5 and Tac antigens. The vast majority of cells did not concomitantly express both markers. The double labelled cells had a lymphoid-like morphology, high nucleus/cytoplasmic ratio and 2-3 nucleoli. The results will be discussed focusing on early and late "stem" cell growth.     

Virological and serological diagnosis of cytomegalovirus infection in bone marrow allograft recipients

To detect cytomegalovirus (CMV) infections, a total of 1,074 cultures of urine, saliva, or blood were collected weekly from 43 consecutive patients undergoing allogeneic bone marrow transplantation. Twenty-three patients were seronegative before transplant and primary infection occurred in 2 (9%). Twenty patients were initially seropositive and recurrent infections occurred in 5 (25%). Three patients in the recurrent group had proven CMV pneumonitis; viraemia was detected in two recipients, while the third had CMV isolated only from bronchial lavage fluid. The serological response of the 43 patients was defined by testing 559 serial sera for specific IgG and IgM antibodies by radioimmunoassay. Passive acquisition of IgG antibodies from blood products was found in 78% of initially seronegative recipients. One patient with primary infection responded in a pattern typical of immunocompetent individuals with long-term production of specific IgG and transient production of specific IgM antibodies. The second patient also had a typical response, but this was delayed until several weeks after the start of virus excretion. In patients with recurrent infections, specific IgM production did not correlate with episodes of virus excretion. Three of five such patients failed to mount a specific IgM response, and these were the only patients in the study to develop CMV pneumonitis. We conclude that CMV infection in bone marrow recipients can only be diagnosed by detection of virus; therefore, the ability of these patients to mount humoral immune responses should not be relied upon for diagnostic purposes.     

Investigation of psychotropic drug-induced blood agranulocytosis

Psychotropic drugs frequently cause agranulocytosis. It is therefore important that patients on these drugs who develop symptoms or signs of infection should have a full blood count performed, and if the neutrophil count is reduced, prompt withdrawal of the drug and, if necessary, immediate supportive care should be given to reduce the incidence of mortality. Once the patient has recovered, investigations can be performed to confirm the diagnosis and incriminate the responsible drug. It is imperative, in order that these tests may be performed, that serum samples are taken at the time of diagnosis of the neutropenic episode, throughout its course and during the recovery period.     

Relation of "lymphoid" phenotype and response to chemotherapy incorporating vincristine-prednisolone in the acute phase of Ph1 positive leukemia.

Forty-four patients with Ph positive leukemia (36 developing blast crisis after chronic phase and eight presenting in acute leukemia) were classified into subgroups on the basis of reactivity of blasts with an anti-serum made against non-T,non-B acute lymphoid leukemia (ALL+), levels of terminal transferase enzyme (TdT+) and morphology. Positivity with anti-ALL serum was the most sensitive and reliable marker, and TdT was an important aid. The presence of "lymphoid" blasts in blast crisis of CML was related to the response to chemotherapy incorporating Vincristine and Prednisolone (VP). Patients with ALL+ blasts frequently (14 of 15 cases) responded to therapy while 21 of 25 patients who had no ALL+ blasts failed to respond. The clinical course of the ALL+ patients was variable: eight patients remitted with return to the appearances of the chronic phase; four patients demonstrated elimination of the Ph1 positive clone with hypoplasia and this was followed by normal (Ph1 negative) marrow regeneration in two. Subsequent relapse was of either the ALL+ "lymphoid" or the ALL-myeloid type. A regimen incorporating VP should be the treatment of choice in "lymphoid" blast crisis of CML.     

Functional compartmentation of DNA precursors in human leukaemoblastoid cell lines

Summary . Human leukaemoblastoid cell lines were incubated with [³H]t hymidine and used to study the utilization for DNA synthesis and degradation of thymine nucleotides labelled via the salvage pathway. Three types of experiments were performed. (1) Cells were continuously labelled with exogenous [3H]thymidine at 3 7°C to compare the incorporation of label into DNA with the specific radioactivities of thymine nucleotides separated by chromatography on polyethyleneimine-cellulose. These studies demonstrated whether one or more functional pool of thymine nucleotides was present. (2) Intracellular thymine nucleotide pools were labelled with [³H]thymidine at 13°C, and the cells were subsequently incubated in unlabelled medium at 37°C in order to quantify the percentage of thymine nucleotides incorporated into DNA. The results showed that 18%, 75%, 75% and 91% of intracellular thymine nucleotides were incorporated into DNA during the chase, in Raji (B lymphoid), Nalm-6 (pre-B cell), HL60 (myeloid) and KM3 (c-ALL) cells respectively, whereas Molt4 (Thy-ALL) cells incorporated 100%. (3) In order to quantify the activity of the degradative pathway for thymine nucleotides in these cell lines, cells were labelled as described in (2) in the presence of cytosine arabinoside (an inhibitor of DNA synthesis). 100%, 90%, 65%, 38% and 20% of labelled thymine nucleotides were degraded in Raji, HL60, Nalm-6, KM3 and Molt-4 respectively. These results confirm our previous conclusion (Taheri et al, 1981a, b) that thymine nucleotides are functionally compartmentalized in human cells. If these results with cell lines can be extrapolated to apply to de novo leukaemia cases, they suggest that the degree of compartmentation differs widely between different leukaemia cell types. Thy-ALL cells utilized all their labelled thymine nucleotides for DNA synthesis, whereas B-ALL, cells utilized only 18% of their labelled thymine nucleotide nucleotides. Thy-ALL cells have the smallest degradative thymine pool and degradative capacity whereas B-ALL cells possess the largest degradative pool and capacity. AML, pre-B-ALL, c-ALL cell lines show intermediate results. If these results reflect those of the normal bone marrow cells from which each of the leukaemias arise, they suggest that with progressive B cell development in the bone marrow, degradative ability for DNA precursors increases and the efficiency of utilization of DNA precursors for DNA synthesis decreases.     

IMMUNOGLOBULINS IN THE SKIN IN DERMATITIS HERPETIFORMIS AND CŒLIAC DISEASE

The unaffected skin of eighteen patients with dermatitis herpetiformis (D.H.), twenty-two patients with cœliac disease (C.D.), and eight controls were examined using direct immunofluorescence and class-specific fluorescein-conjugated anti-human IgA, IgM, and IgG antisera. All eighteen patients with D.H. showed IgA deposits in the skin: in seventeen the deposits were only found in the dermal papillæ, whilst in one it was found in a continuous line below the basement membrane, confirmed by immuno-electronmicroscopy. IgM deposits were also found in the dermal papillæ in three patients with D.H. and IgG deposits below the basement membrane in one patient. In cœliac disease, however, only one of the twenty-two patients showed papillary IgA deposits and one had continuous IgM deposits. These immunoglobulin deposits in D.H. and C.D. seem to be on the reticulin of the dermal papillæ. It is suggested that in D.H. there is a fault of the reticulin in the skin and small intestine, whilst in cœliac disease it is present in the small intestine but not in the skin. The reticulin cross-reacts with gluten complexes to give rise to an immunological reaction. In support of this hypothesis we have demonstrated cross-reactivity between gluten and reticulin.     

The Effect of Deoxyuridine, Vitamin B12, Folate and Alcohol on the Uptake of Thymidine and on the Deoxynucleoside Triphosphate Concentrations in Normal and Megaloblastic Cells

Deoxyuridine suppression of labelled thymidine uptake tests were performed in the bone marrows of 58 patients with megaloblastic anaemia (haemoglobin less than 10.0 g/dl) and invariably gave values (range 10.3-58.8%) above the range in 16 control marrows (range 1.0-9.0%). Folinic acid corrected the test equally well in either folate or vitamin B12 deficiency, even at concentrations as low as 60 ng/ml. Folic acid also corrected the test equally well in either deficiency but was only effective at concentrations down to 5 microgram/ml. Vitamin B12 (100 microgram/ml) only corrected the test in vitamin B12 deficiency and 5-methyltetrahydrofolate only corrected the test in folate deficiency at the concentrations tested between 60 and 1.2 microgram/ml. Among 16 patients with subnormal serum levels of both vitamin B12 and folate, vitamin B12 partially corrected the test in eight, including all five with pernicious anaemia, but had no effect in the other eight. Despite the clear-cut results of the dU suppression test, measurement of the deoxythymidine triphosphate (dTTP) concentration in normal and megaloblastic phytohaemagglutinin stimulated lymphocyte cultures or short-term bone marrow cultures gave no clear-cut differences between normal and megaloblastic cells after addition of deoxyuridine nor did the addition of vitamin B12, folic acid or folinic acid either alone or with deoxyuridine produce consistent changes in the dTTP concentration in lymphocytes or bone marrow cells in megaloblastic anaemia. Alcohol caused a rise in deoxyadenosine triphosphate concentration in normal PHA-stimulated lymphocytes which was concentration dependent but caused no consistent change in any of the other three deoxynucleoside triphosphate (dNTP) concentrations. Diphenylhydantoin (10(-3)M, 10(-4)M) had no consistent effect on any of the four dNTP concentrations.