Biomedical subjects

S Vadhan-Raj

Publications and source records attributed to S Vadhan-Raj.

80 records · Page 5Linked to original sources

PubMed1987

Effects of recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndromes.

The myelodysplastic syndromes are characterized by ineffective hematopoiesis and refractory cytopenias. In an attempt to improve hematopoiesis, we administered recombinant human granulocyte--macrophage colony-stimulating factor (GM-CSF) to eight patients with myelodysplastic syndrome, as part of a Phase I trial. The GM-CSF was given by continuous intravenous infusion daily for two weeks and then again after a two-week rest period. Over the entire dose range tested (30 to 500 micrograms per square meter of body-surface area), treatment was associated with marked increases in peripheral-blood leukocytes (5- to 70-fold), including granulocytes (5- to 373-fold), in all eight patients. The absolute number of monocytes, eosinophils, and lymphocytes increased in all patients. Three of eight patients also had 2- to 10-fold increases in platelet counts and improvement in erythropoiesis, with the result that two of three patients who had required red-cell and platelet transfusions no longer needed them (at 20 to 27 weeks of follow-up). Treatment was also associated with increased marrow cellularity and a decreased percentage of blasts in the bone marrow of patients with excess blasts, resulting in an increase in the ratio of differentiated myeloid cells to immature myeloid cells. We observed relatively few side effects, but bone pain was dose-limiting when it was associated with high white-cell counts. Our results showed that GM-CSF is a potent stimulator of hematopoiesis in vivo and may produce hematologic improvement in the short term (8 to 32 weeks of observation) in patients with myelodysplastic syndrome. More experience, with longer follow-up periods, will be necessary to assess the long-term safety and efficacy of this new treatment.

Adult↗

PubMed1987

Interferon in AIDS.

Interferons are natural proteins with important regulatory functions. Impairment of their production may help to explain many of the immunologic abnormalities and disease susceptibilities of AIDS patients, while excessive production of an unusual type of interferon may explain some of the systemic symptoms associated with the syndrome. In a subset of patients, alpha interferons may have therapeutic potential against a major complication of the syndrome, Kaposi's sarcoma. Finally, both alpha and gamma interferons have potential, but as yet unexplored roles to play in the treatment of HTLV-III/LAV viremia and in the control of secondary infectious complications of the syndrome.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Kaposi's sarcoma and the acquired immune deficiency syndrome. Treatment with recombinant interferon alpha and analysis of prognostic factors.

Interferon alfa-2a (Roferon-A, Hoffmann-La Roche Inc., Nutley, NJ) was used to treat sequential groups of patients with Kaposi's sarcoma associated with the acquired immune deficiency syndrome (AIDS). Major antitumor effects (complete or partial responses) were observed in 38% of the patients treated initially with high-dose interferon alfa-2a and in 17% of patients in whom the dose was increased after low-dose treatment failed. A low dose of interferon alfa-2a was ineffective; one patient (3%) showed a partial response. Patients whose tumors responded to interferon treatment showed a significantly lower rate of opportunistic infection, as well as a longer survival than nonresponders. The status of pretreatment immune function was important in predicting the response to interferon treatment. The implication of these findings with respect to understanding the mechanism of action of interferon and the definition of the most appropriate patients for interferon treatment are discussed.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Phase I trial of recombinant interferon gamma in cancer patients.

Interferon gamma (IFN-gamma) is a lymphokine with potent in vitro effects on cell growth and immune function. We have investigated the effects of rIFN-gamma (sp act approximately 2 X 10(7) U/mg, purity greater than 99%) in 16 evaluable patients with advanced malignancy in a phase 1 trial. Patients were treated with six-hour intravenous (IV) infusions daily, five days a week for 2 weeks. After a 2-week rest period, the IV treatment cycle was repeated. Responders were maintained on repeated IV treatment cycles or daily intramuscular (IM) injections. Patients were entered at fixed dose levels of 0.1, 0.5, or 1.0 mg/m2/d. The maximum safely tolerated dose was 0.5 mg/m2. The most common side effects were constitutional symptoms, including fever, chills, fatigue, and myalgias. Reversible and transient increases in hepatic transaminase and decrease in granulocyte counts were seen. Treatment was associated with a dose-dependent increase in serum levels of beta 2 microglobulin. Partial responses (PRs) were observed in one patient with Hodgkin's disease and one patient with chronic lymphocytic leukemia. Fairly constant levels of serum IFN were found at four and six hours during infusion, followed by a rapid decline within one to two hours. We conclude that rIFN-gamma can be safely administered by a six-hour IV infusion and that it can induce in vivo some of the biologic effects reported in in vitro studies.

Adult↗

PubMed1986

Immunological variables as predictors of prognosis in patients with Kaposi's sarcoma and the acquired immunodeficiency syndrome.

Multivariate analysis was used to identify which of a large number of pretreatment immunological parameters correlated with therapeutic response, subsequent development of opportunistic infection, and survival from the time of diagnosis in a group of 70 patients with Kaposi's sarcoma and acquired immunodeficiency syndrome treated with recombinant leukocyte A interferon. In a logistic regression model, delayed type hypersensitivity response to one or more recall antigens and high proliferative response to Escherichia coli were significant predictors for response to recombinant leukocyte A interferon (for the model, P = 0.01). For prediction of the development of opportunistic infection, the model selected low proliferative responses to phytohemagglutinin and E. coli (P less than 0.001). Favorable factors predicting survival in the Cox regression model were the absence of endogenous serum interferon activity and a high proliferative response to E. coli (P less than 0.001). The estimated median survival for the group with endogenous serum interferon activity and low E. coli response was 12 months; the median has not yet been reached for the group with no serum interferon and a high E. coli response. We conclude that immunological parameters may be useful in predicting prognosis in patients with Kaposi's sarcoma and acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Phase I trial of recombinant interferon gamma by 1-hour i.v. infusion.

Fifteen patients with advanced malignancy were treated with recombinant interferon gamma (rIFN-gamma) (specific activity approximately 2 X 10(7) units/mg, purity greater than 99%) given by 1-hour iv infusion three times a week for 6 weeks, at fixed dose levels of 0.1, 0.5, 1.0, or 2.0 mg/m2/day. The common side effects were constitutional symptoms, including fever, chills, myalgias, and headache, but these were less severe than those observed following daily 6-hour iv infusions. Significant changes in blood cell counts and routine serum chemistries were not observed, but there was a dose-dependent increase in serum triglyceride levels. The maximum safely tolerated dose achieved was 1.0 mg/m2/day. Peak serum interferon levels occurred at the midpoint of the infusion and were dose-dependent. rIFN-gamma was rapidly cleared from serum and no detectable activity was found 2 hours after the infusion. Two patients, both with B-cell malignancies, showed objective evidence of tumor regression during the treatment. Treatment was associated with an increase in serum levels of beta 2-microglobulin and the H2O2 secretory capacity of peripheral blood monocytes. We conclude that rIFN-gamma administered by short iv infusion can induce biological activities and causes less toxicity than when given by prolonged iv infusion.

Adult↗

PubMed1985

Administration of recombinant interferon gamma to cancer patients enhances monocyte secretion of hydrogen peroxide.

Recombinant interferon gamma (rIFN-gamma) activates macrophage antimicrobial and antitumor functions and related metabolic processes, including secretion of reactive oxygen intermediates in mice and in cultured mouse and human macrophages. To look for similar actions in man, we monitored the H2O2 secretory capacity of monocytes from cancer patients receiving intravenous rIFN-gamma at 0.1, 0.5, or 1.0 mg/m2 of body area over 6 hr daily or over 1 hr on alternate days. Monocytes taken just before the first infusion served as controls and were comparable to normal donor monocytes in secretion of H2O2. Monocytes from 11 of the 13 subjects (85%) studied through 20 treatment cycles responded to rIFN-gamma with elevation in H2O2 secretion in greater than or equal to 67% of the tests conducted greater than 1 hr after the start of treatment. Five of the five subjects tested had monocytes with diminished H2O2 secretory capacity when tested immediately after a 1-hr infusion of rIRN-gamma, at which time the amount of adherent mononuclear cell protein recovered from the blood averaged only 24% of the control. At all other times tested (from 6 hr to 5 days after infusion) combined results for all subjects showed enhancement of H2O2 releasing capacity. Statistically significant mean increases ranged from 1.4- to 2.8-fold above the control and included the sets in which monocytes collected 24 hr following a single infusion were assayed the same day or the next. By the criterion of enhanced H2O2 secretory capacity, the ability of rIFN-gamma to activate mononuclear phagocytes is manifest upon its administration to patients with advanced malignancy.

Adult↗

PubMedDate not supplied

Clinical applications of colony-stimulating factors.

Colony-stimulating factors (CSFs) are a family of regulatory glycoprotein hormones that promote the proliferation and differentiation of hemopoietic progenitor cells and augment the functions of mature effector cells in vitro. The recent cloning of human genes and the availability of sufficient quantities of recombinant purified growth factors have made it possible to evaluate their therapeutic potential in cytopenic states. Initial studies with GM-CSF have demonstrated its ability to increase neutrophil, monocyte, and eosinophil counts in patients with acquired immune deficiency syndrome (AIDS), myelodysplastic syndrome (MDS), and aplastic anemia. Both GM-CSF and G-CSF reduce the duration of neutropenia following chemotherapy and accelerate hematopoietic recovery in patients undergoing intensive chemotherapy and autologous bone marrow transplantation. Studies are now ongoing to determine the optimal dose, route, schedule of administration, and long-term effects. While the appropriate settings for the use of different CSFs remain to be determined, the initial results of clinical trials are of great interest and suggest that hematopoietic growth factors will play an important role in several clinical arenas.

Clinical Trials as Topic↗