Surfactant protein-A enhances respiratory syncytial virus clearance in vivo.

To determine the role of surfactant protein-A(SP-A) in antiviral host defense, mice lacking SP-A (SP-A-/-) were produced by targeted gene inactivation. SP-A-/- and control mice (SP-A+/+) were infected with respiratory syncytial virus (RSV) by intratracheal instillation. Pulmonary infiltration after infection was more severe in SP-A-/- than in SP-A+/+ mice and was associated with increased RSV plaque-forming units in lung homogenates. Pulmonary infiltration with polymorphonuclear leukocytes was greater in the SP-A-/- mice. Levels of proinflammatory cytokines tumor necrosis factor-alpha and interleukin-6 were enhanced in lungs of SP-A-/- mice. After RSV infection, superoxide and hydrogen peroxide generation was deficient in macrophages from SP-A-/- mice, demonstrating a critical role of SP-A in oxidant production associated with RSV infection. Coadministration of RSV with exogenous SP-A reduced viral titers and inflammatory cells in the lung of SP-A-/- mice. These findings demonstrate that SP-A plays an important host defense role against RSV in vivo.

GM-CSF-deficient mice are susceptible to pulmonary group B streptococcal infection.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) gene-targeted mice (GM-/-) cleared group B streptococcus (GBS) from the lungs more slowly than wild-type mice. Expression of GM-CSF in the respiratory epithelium of GM-/- mice improved bacterial clearance to levels greater than that in wild-type GM+/+ mice. Acute aerosolization of GM-CSF to GM+/+ mice significantly enhanced clearance of GBS at 24 hours. GBS infection was associated with increased neutrophilic infiltration in lungs of GM-/- mice, while macrophage infiltrates predominated in wild-type mice, suggesting an abnormality in macrophage clearance of bacteria in the absence of GM-CSF. While phagocytosis of GBS was unaltered, production of superoxide radicals and hydrogen peroxide was markedly deficient in macrophages from GM-/- mice. Lipid peroxidation, assessed by measuring the isoprostane 8-iso-PGF2alpha, was decreased in the lungs of GM-/- mice. GM-CSF plays an important role in GBS clearance in vivo, mediated in part by its role in enhancing superoxide and hydrogen peroxide production and bacterial killing by alveolar macrophages.

The biology of tumor growth in the non-Hodgkin's lymphomas. A dual parameter flow cytometry study of 220 cases.

Dual parameter flow cytometry studies (cell DNA content and electronic cell volume) were performed in 220 cases of non-Hodgkin's lymphoma. All cases were characterized as B or T cell malignancies, based on immunologic surface marker characteristics. Aneuploidy by flow cytometry was more common among the B cell lymphomas than among the T cell lymphomas, and was most common among the large B cell lymphomas and B cell lymphomas of intermediate size. Ploidy index distributions showed a prominent hyperdiploid peak, as well as tumor cell populations with near-tetraploid DNA contents. In serial studies, a decrease in ploidy index was observed in association with clinical and histologic transformation in one case. The highest S fractions were observed among the large and intermediate B cell lymphomas and among the aggressive T cell lymphomas. In clinical samples consisting of mixtures of diploid and aneuploid populations, the data on the aneuploid components could often be separated from other components of the mixture in multiparameter studies on the basis of the larger electronic cell volumes of the aneuploid cells. In each case, the aneuploid large cell component almost invariably had a higher S fraction than the residual component(s) of the mixture. Overall, the data are consistent with a model of clonal selection and clonal evolution in the lymphomas in which early cytogenetic abnormalities that involve little or no change in total cell DNA content are followed by cell tetraploidization that is associated with cytogenetic instability and chromosome loss over the course of time.

Lactobacillus johnsonii supplementation attenuates respiratory viral infection via metabolic reprogramming and immune cell modulation.

Regulation of respiratory mucosal immunity by microbial-derived metabolites has been a proposed mechanism that may provide airway protection. Here we examine the effect of oral Lactobacillus johnsonii supplementation on metabolic and immune response dynamics during respiratory syncytial virus (RSV) infection. L. johnsonii supplementation reduced airway T helper type 2 cytokines and dendritic cell (DC) function, increased regulatory T cells, and was associated with a reprogrammed circulating metabolic environment, including docosahexanoic acid (DHA) enrichment. RSV-infected bone marrow-derived DCs (BMDCs) from L. johnsonii-supplemented mice had altered cytokine secretion, reduced expression of co-stimulatory molecules, and modified CD4+ T-cell cytokines. This was replicated upon co-incubation of wild-type BMDCs with either plasma from L. johnsonii-supplemented mice or DHA. Finally, airway transfer of BMDCs from L. johnsonii-supplemented mice or with wild-type derived BMDCs pretreated with plasma from L. johnsonii-supplemented mice reduced airway pathological responses to infection in recipient animals. Thus L. johnsonii supplementation mediates airway mucosal protection via immunomodulatory metabolites and altered immune function.

AIDS-related malignancies: the emerging epidemic.

The incidence of three malignancies has increased in conjunction with the epidemic of human immunodeficiency virus (HIV) disease, and they are currently considered acquired immunodeficiency syndrome (AIDS)-defining conditions. These are Kaposi's sarcoma, associated with AIDS since the onset of the epidemic in 1981; intermediate or high-grade B-cell lymphoma, which became AIDS-defining in 1985; and cervical carcinoma in HIV-infected women, formally recognized as an AIDS-defining diagnosis on January 1, 1993. Approximately 40% of all patients with AIDS have developed cancer during the course of HIV infection. Further, as survival has improved in HIV disease, the incidence of these malignancies has increased. It is thus expected that greater numbers of patients with AIDS-related lymphoma and cervical cancer will be diagnosed in the years ahead. The epidemiologic factors associated with neoplastic disease differ among patients with the three AIDS-related malignancies. The pathogenesis of neoplastic disease also differs. The specific etiologic steps in the development of AIDS-related Kaposi's sarcoma and lymphoma are currently unknown. However, a great deal of information has already been acquired, which may have bearing on the pathogenesis of malignant disease in general, as well as the elucidation of future therapeutic modalities. The specific epidemiologic, etiologic, and clinical characteristics of the AIDS-related malignancies will be described herein. It is hoped that this review will serve to outline our current understanding of this area, to introduce the questions and controversies which are apparent in the field, and to mention those areas in which future research might be focused.

Liposome-encapsulated methotrexate interactions with human chronic lymphocytic leukemia cells.

The uptake of free and liposome-entrapped methotrexate (MTX) by human chronic lymphocytic leukemia cells was compared under incubation conditions resembling those encountered in vivo. Liposome encapsulation enhanced up to 200 times the association of MTX with these cells. Autoradiographic studies established an association of [3H]MTX liposomes with the cells. Such a mode of delivery did not significantly increase the amount of drug available to inhibit dihydrotolate dehydrogenase, which suggested that the liposome content was not readily available to the cytoplasmic sites of action. Increased doses of encapsulated MTX resulted in enzyme inhibitions that were similar to those obtained with the free drug. This finding demonstrates that higher doses of MTX delivered by liposomes could be potentially useful in overcoming drug-transport resistance.

Epidemiological and biological study of acquired immunodeficiency syndrome-related lymphoma in the County of Los Angeles: preliminary results.

A population-based case control study of intermediate- and high-grade lymphoma in the County of Los Angeles, CA, was initiated in 1989. Human immunodeficiency virus (HIV)-positive lymphoma patients are compared to HIV-negative lymphoma patients, to HIV-positive controls with acquired immunodeficiency syndrome but without lymphoma, and to HIV-positive asymptomatic individuals. The HIV-negative lymphoma cases are compared to neighborhood controls, who are matched in terms of age, sex, race/ethnicity, and socioeconomic status. All cases are reviewed for pathology by a single group of pathologists. All cases and controls are studied for HIV, Epstein-Barr virus (EBV), and human herpesvirus 6 antigens and antibodies. Tissues from HIV-positive and -negative cases are studied for immunoglobulin gene rearrangement, presence of EBV and HIV, c-myc oncogene rearrangements, and karyotypic analysis. To date, with 294 lymphoma cases and 181 control cases interviewed, high-grade lymphoma has been diagnosed in 82% of the HIV-positive cases versus 40% of the HIV-negative cases (P = 0.001). Although elevated titers of EBV-viral capsid antigen were demonstrated in 82% of HIV-positive versus 50% of HIV-negative lymphoma cases, the geometric mean titer of EBV-viral capsid antigen is similar among HIV-positive lymphoma cases and HIV-positive controls. The geometric mean titer of human herpesvirus 6 antibodies was similar in HIV-positive and HIV-negative lymphoma cases and in the control populations. Monoclonality was demonstrated in all cases of lymphoma. EBV genome was demonstrated within lymphoma DNA in 68% of HIV-positive and 15% of HIV-negative lymphoma cases. Further study will be required to elucidate the full mechanisms of pathogenesis of the acquired immunodeficiency syndrome-related lymphomas.

Surfactant protein A (SP-A) gene targeted mice.

Mice lacking surfactant protein A (SP-A) mRNA and protein in vivo were generated using gene targeting techniques. SP-A (-/-) mice have normal levels of SP-B, SP-C and SP-D mRNA and protein and survive and breed normally in vivarium conditions. Phospholipid composition, secretion and clearance, and incorporation of phospholipid precursors are normal in the SP-A (-/-) mice. Lungs of SP-A (-/-) mice have markedly decreased tubular myelin figures and clear Group B streptococci and Pseudomonas aeruginosa less efficiently than SP-A wild type mice. These studies of SP-A (-/-) mice demonstrate that SP-A has an important role in the innate immune system of the lung in vivo.

Reproductive factors and risk of intermediate- or high-grade B-Cell non-Hodgkin's lymphoma in women.

PURPOSE: The incidence rates of non-Hodgkin's lymphoma (NHL) unrelated to human immunodeficiency virus infection are lower for women than for men; yet, few factors have been identified that may account for this difference in risk. NHL is difficult to study epidemiologically because this disorder represents a group of malignancies that differ in terms of morphologic presentation, immunologic features, genetic characteristics, prognosis, and etiology. PATIENTS AND METHODS: We conducted a population-based case-control study in women to determine whether reproductive factors or hormonal exposures might be related to the risk of high- or intermediate-grade B-cell NHL. We interviewed 177 female residents of Los Angeles County who were diagnosed with high- or intermediate-grade B-cell NHL between 1989 and 1992; each case patient was individually matched on age and race to a control subject who lived in her neighborhood. RESULTS: Women who had used oral contraceptives had significantly lower risk of intermediate- or high-grade NHL (multivariate odds ratio [OR] = 0.47; 95% confidence interval [CI], 0.26 to 0.86) than women who had never used these compounds. Among parous women, those who had used lactation suppressants (which contain high levels of estrogen) had significantly lower risk of NHL (multivariate OR = 0.50; 95% CI, 0.29 to 0.85) than unexposed women. Postmenopausal women had a somewhat greater risk of NHL than premenopausal women, whereas those postmenopausal women who had used hormone replacement therapy (HRT) (primarily estrogen) had somewhat lower risk than those who had not used HRT. CONCLUSION: Exogenous estrogens seem to have a protective effect on the risk of high- and intermediate-grade B-cell NHL. Although the mechanisms for such protection are not known, alterations in immune reactivity, cytokine expression, or B-cell modulation may play a role.

Malignant lymphoma: cardiac involvement at initial presentation.

Malignant lymphoma rarely involves the heart at initial presentation. We have cared for nine cases in the past 8 years. The median age was 45 years (range, 27 to 68). Initial presenting symptoms included chest pain in four, gastrointestinal (GI) symptoms in three, and constitutional "B" symptoms in two. Echocardiography was the most useful noninvasive procedure, and was abnormal in the eight cases studied. Echocardiographic findings included pericardial effusion in six, and mass lesions within the heart in five. Morphologically, the lymphoma was high-grade small noncleaved in four, immunoblastic sarcoma in one, and diffuse large-cell type in four. Clinical staging workup revealed widely disseminated disease in seven. In spite of multiagent chemotherapy, survival was short (median, 1.5 months). Interestingly, four of these patients were homosexual or bisexual men, who fulfill the criteria for acquired immune deficiency syndrome (AIDS).

B cell acute lymphocytic leukemia in adults. Clinical, morphologic, and immunologic findings.

Acute lymphocytic leukemia (ALL) is a heterogeneous group of disorders, clinically, immunologically, and pathologically. ALL of a B cell phenotype (B-ALL) is the least common. We have studied ten adult patients with B-ALL, none of whom had a tumor mass. The median age was 56 years (range, 30 to 90). A history of an altered immune state was noted in four cases: a distant history of Hashimoto's thyroiditis in one, pregnancy in one, and acquired immunodeficiency syndrome in two. Two patients presented with CNS involvement, and in two additional patients CNS leukemia developed during the course of disease. By the French-American-British (FAB) classification system, L3 leukemic morphology was present in nine, whereas L2 was present in one. Circulating leukemic blasts varied from less than 500/dL to greater than 15,000/dL. Eight patients were thrombocytopenic, and eight were anemic at presentation. Immunologic marker studies on leukemic blasts revealed monoclonal kappa light chain marking in nine and monoclonal lambda in one. Following chemotherapy, complete remission was achieved in three patients, two of whom experienced relapse within 9 months. The median survival for the group was 3 months, and only one patient experienced long-term, disease-free survival. We conclude that B-ALL in the adult presents with the classic L3 morphologic picture in the majority and is associated with extremely short survival.

The effect of compliance with treatment on survival among patients with hematologic malignancies.

Ninety-four newly diagnosed patients with hematologic malignancies were monitored for compliance with oral medication and scheduled clinic appointments over a 6-month treatment period. They were assigned at entry either to a control condition or an intervention condition designed to improve compliance. Compliance with medication was assessed objectively with serial serum drug and metabolite levels, as well as with self-report indices obtained on a monthly basis. Medical records were abstracted to obtain data on the number of appointments kept, treatment given, disease characteristics, and survival. On univariate analyses using the log-rank test, five variables were found to be significantly related to survival. These included compliance with allopurinol (probably acting as a surrogate for self-medication with other chemotherapeutic agents) (P = .007), control versus educational program cohort (P less than .001), disease severity (P = .009), Karnofsky at diagnosis (P = .011), sex (P = .084), and clinic appointments kept (P = .043). In hierarchical proportional hazards models, the following variables were associated with decreased risk of death: disease severity (P less than .025), keeping over 60% of appointments (P less than .05), allopurinol/oxipurinol compliance (P less than .01), and educational program cohort (P less than .05). After controlling for all other variables, three variables were associated with increased survival: high disease severity (relative risk [RR] = 2.48), high compliance with allopurinol (RR = .45), and educational program cohort (RR = .39). We conclude that compliance with oral medication has a significant effect on patient survival. In addition, the use of special educational and supportive programs designed to improve patient compliance are associated with significant prolongation of patient survival due to, as well as independent of their effects on compliance.

Radiation therapy for acquired immunodeficiency syndrome-related Kaposi's sarcoma.

Twenty-four patients with acquired immunodeficiency syndrome (AIDS) received 80 courses of radiation therapy for Kaposi's sarcoma (KS). Pain and other symptoms due to mass effects were well controlled, but KS lesions often persisted in irradiated sites. Acute radiation toxicity to doses of approximately 2,000 cGy in ten fractions to the oral cavity and/or the foot were significant and may limit the dose and the efficacy of radiotherapy in patients with the epidemic form of KS.

Prognostic factors in the treatment of human immunodeficiency virus-associated non-Hodgkin's lymphoma: analysis of AIDS Clinical Trials Group protocol 142--low-dose versus standard-dose m-BACOD plus granulocyte-macrophage colony-stimulating factor. National Institute of Allergy and Infectious Diseases.

PURPOSE: The overall results of chemotherapy in human immunodeficiency virus (HIV)-associated non-Hodgkin's lymphoma (NHL) have been poor. To define a subgroup of patients who may have a better outcome, an analysis of prognostic factors was performed of patients treated in AIDS Clinical Trials Group (ACTG) protocol 142, a phase III randomized trial of low-dose versus standard-dose methotrexate, bleomycin, doxorubicin, cyclophosphamide, vincristine, and dexamethasone (m-BACOD) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) for the treatment of patients with newly diagnosed HIV-associated NHL. MATERIALS AND METHODS: The following baseline variables were included as potential predictors of survival among 192 patients who received treatment: age; intravenous drug use (IVDU); specific type of sexual contact as risk factors (homosexual, bisexual, or heterosexual contact); prior AIDS diagnosis; CD4 cell count; serum lactic acid dehydrogenase (LDH); histology; Karnofsky performance status (KPS); stage; B symptoms; race (white/nonwhite); nodal involvement; extranodal involvement; number of extranodal sites; specific sites: bone marrow, liver, kidney, lung, or gastrointestinal tract; and treatment arm (standard-dose m-BACOD/low-dose m-BACOD). RESULTS: Age greater than 35 years, IVDU, stages III/IV, and CD4 cell counts less than 100/microL were adverse prognostic factors in multivariate analyses using the Cox proportional hazards model. The median overall survival for patients with none or one of the adverse factors was 46 weeks, with two was 44 weeks, and with three or four was 18 weeks. At 144 weeks, 29.5% of patients with none or one, 16.9% with two, and 0% with three or four factors were alive (P < .001). CONCLUSION: Long-term survival can be achieved in approximately one third of patients with HIV-associated NHL with favorable characteristics.

Phase I/II clinical and pharmacokinetic evaluation of liposomal daunorubicin.

PURPOSE: Since liposomal encapsulation of anticancer drugs may enhance antitumor activity while reducing toxicity in vitro, we evaluated liposomally encapsulated daunorubucin (DaunoXome; Vestar, Inc, San Dimas, CA) for safety, pharmacokinetics, and potential efficacy in patients with AIDS-related Kaposi's sarcoma (AIDS-KS). PATIENTS AND METHODS: Forty patients with advanced AIDS-KS were accrued. Successive cohorts received DaunoXome at doses of 10, 20, 30, and 40 mg/m2 given once every 3 weeks, and 40, 50, and 60 mg/m2 given once every 2 weeks. Selected KS and solid-tumor patients underwent pharmacokinetic evaluation. RESULTS: The area under the plasma concentration curve (AUC) ranged from 16.9 micrograms.h/mL to 375.3 micrograms./mL and the alpha half-life ranged from 7.8 to 8.3 hours at 10 mg/m2 to 60 mg/m2, respectively. Both pharmacokinetic profiles were significantly better compared with free daunorubicin. DaunoXome was well tolerated with no significant alopecia, mucositis, or vomiting. Neutropenia (< 1,000/microL occurred in 17% of cycles and was severe (< 500/microL) in only 2%. Anemia and thrombocytopenia were uncommon. Other adverse events included mild to moderate fatigue, nausea, and diarrhea. Even after cumulative doses greater than 1,000 mg/m2, no significant declines in cardiac function were observed. Twenty-two patients who received 50 and 60 mg/m2 were assessable for tumor response; 12 (55%) had a partial response (PR) or clinical complete response (CR). The median survival duration in all patients was 9 months. Prognostic factors for short survival were low CD4 lymphocyte counts (P = .004) and prior anthracycline therapy (P = .02). CONCLUSION: DaunoXome has an improved pharmacokinetic profile compared with free daunorubicin, and is well tolerated. DaunoXome can be given safely at doses up to 60 mg/m2 every 2 weeks and has significant antitumor activity in patients with AIDS-KS.

Compliance with oral drug therapy in patients with hematologic malignancy.

Compliance with oral self-administered allopurinol (daily medication) and prednisone (intermittent medication) as well as compliance with monthly scheduled clinic appointments, were examined in 108 patients with newly diagnosed hematologic malignancy. Baseline levels of compliance (control group) were compared to results obtained after implementation of three intervention packages, whose aim was to increase compliance. The packages included combinations of education, home psychologic support and restructuring, and training in pill taking. A 24-hour profile of the two drugs and their metabolites was first determined. Serum samples were then obtained monthly over 6 months and analyzed for presence of the drugs. Control patients were fully compliant with allopurinol only 16.8% of the time. This rate increased significantly (44% to 48% of the time) for those who received any one of the intervention programs. With respect to prednisone, control patients were compliant 26.8% of the time, with no real improvement after interventions. Finally, self reports overestimated compliance by a factor of two when compared to drug analysis. The results indicated that full compliance with oral medications was remarkably low among our patients who have treatable and in some cases curable hematologic malignancy. However, compliance can be significantly improved by the use of various intervention packages.

Results of initial lymph node biopsy in homosexual men with generalized lymphadenopathy.

Persistent, generalized lymphadenopathy (PGL) is considered part of the acquired immunodeficiency syndrome (AIDS)-related complex. The clinical course is usually benign, although some patients may evolve to AIDS. Characteristic features on lymph node biopsy have been described. Recently, large series of PGL have been reported in which many study patients have not undergone initial diagnostic biopsy. The value of such biopsy has been questioned. We report the clinical, pathologic, and laboratory findings in six homosexual men initially considered as potential candidates for study of the natural history of PGL. They were excluded by initial lymph node biopsy, which revealed small-cleaved lymphoma in two, focal Kaposi's sarcoma in two, disseminated mycobacterium tuberculosis in one, and histoplasma encapsulatum in one. The clinical and laboratory data from these six patients were compared with those from 34 patients with biopsy-proven PGL; no statistically significant difference in any prebiopsy clinical parameter was found. We conclude that initial lymph node biopsy may reveal changes other than reactive hyperplasia in homosexual men with generalized lymphadenopathy.

AIDS-related malignant lymphoma: results of prospective treatment trials.

Twenty-two consecutive patients with high-grade, B-cell lymphomas related to the acquired immunodeficiency syndrome (AIDS) were accrued onto two sequential phase II studies, consisting of a standard regimen (M-BACOD, group no. 1, N = 13), or a novel, intensive regimen (group no. 2, N = 9), which included high-dose cytosine arabinoside (HD-Ara-C), and high-dose methotrexate (HD-MTX), in an attempt to prevent CNS relapse and improve response rates. Stage IV disease was present in 82%. Complete remission (CR) was achieved in seven of 13 patients (54%) in group no. 1, and in three of nine (33%) group no. 2 (P = NS). By multivariate analysis, the most significant factor in predicting response was a Karnofsky performance score (KPS) greater than 60 (P = .04). Three of the ten patients who achieved CR on either regimen have relapsed; in all, five of 13 patients (31%) in group no. 1 have achieved disease-free survival for more than 1 year, compared with one of nine (11%) in group no. 2. CNS progression occurred in six patients in group no. 2, and in two patients in group no. 1. Hematologic toxicity was significantly greater in group no. 2, and these patients had an increased risk of opportunistic infection (one in group no. 1 v seven in group no. 2; P less than .01). Survival was similar, with a median of 11 months in group no. 1 and 6 months in group no. 2. We conclude that the intensive regimen of combination chemotherapy described here is associated with significant risk of early death due to opportunistic infection in patients with AIDS-related lymphoma, and that progression in the CNS remains a major problem. Trials of combination chemotherapy of a less intensive nature, perhaps in combination with immunomodulators or antiretroviral agents should be explored.

Mitoguazone therapy in patients with refractory or relapsed AIDS-related lymphoma: results from a multicenter phase II trial.

PURPOSE: Patients with AIDS-related lymphoma usually have extensive lymphomatous disease, with relatively frequent involvement of the CNS. Approximately half may achieve complete remission after chemotherapy. Mitoguazone, an inhibitor of polyamine biosynthesis, has demonstrated efficacy in patients with de novo recurrent lymphoma. The drug is relatively nonmyelotoxic and may cross the blood-brain barrier. The current study was designed to assess the safety and potential efficacy of mitoguazone in patients with relapsed or refractory AIDS-lymphoma. PATIENTS AND METHODS: Thirty-five patients were accrued, all of whom had failed one (51%) or multiple (two to six) prior regimens. Mitoguazone (600 mg/m2) was given intravenously on days 1 and 8, and then every 2 weeks, until best response, progression, or toxicity. RESULTS: The median age was 39 years. High-grade lymphoma was diagnosed in 29 patients (83%). Extranodal disease was present in 30 patients (86%), with multiple extranodal sites (two to seven) in 18 (51%). The median CD4 cell count at study entry was 66/dL (range, zero to 549). Twenty-six patients were assessable for response. The objective response rate was 23% (95% confidence interval [CI], 6.9 to 39.3), with complete remission in three patients (11.5%), and partial remission (PR) in three patients (11.5%). Six patients experienced stable disease. Median survival from study entry was 2.6 months for the group as a whole; 21.5 months (range, 3.8 to 29.1) in complete responders, 5.6 months (range, 3.8 to 34.8) in partial responders. The most common toxicities occurred solely during drug infusion and included vasodilation (63%), paresthesia (86%), and somnolence (17%). Fourteen patients (40%) experienced nausea and 16 (46%) vomiting (grade 3 in one). Ten patients (29%) developed stomatitis, including grade 3 in two and grade 4 in one. Seven patients (20%) developed neutropenia, with grade 4 in one. Thrombocytopenia occurred in nine patients (26%). While on study, three patients developed sepsis, four had pneumonia, and two developed opportunistic infections. CONCLUSION: Mitoguazone is an effective agent in patients with multiply relapsed or refractory AIDS-related lymphoma, with acceptable toxicity. Further study in patients with newly diagnosed disease is warranted.

All-trans-retinoic acid effects the growth, differentiation and apoptosis of normal human myeloid progenitors derived from purified CD34+ bone marrow cells.

We have previously shown that all-trans retinoic acid (ATRA) increases the number of CFU-GM colonies grown from unseparated human bone marrow cells with crude sources of colony stimulating factors. In this study, we further characterized the effect of ATRA on the growth of CFU-GM stimulated by individual cytokines from multiple samples of CD34+ enriched or purified human bone marrow cells. The number of IL-3- or GM-CSF-induced CFU-GM with 3 x 10(-7) M ATRA was 3.25+/-1.13, and 2.17+/-0.8-fold greater respectively, compared to controls without ATRA, while G-CSF had no effect and the ratio of colony-induced with or without ATRA was 1.06+/-0.17 (P = 0.00012). No colonies grew with ATRA + IL-6 or ATRA without a cytokine. Maximum enhancing effect on IL-3-induced CFU-GM occurred when ATRA was added on day 2, gradually diminished when delaying ATRA, and in cultures of day 9 or older adding ATRA had no effect. In 14 days liquid cultures of purified CD34+ cells with IL-3, ATRA increased the number of myeloid differentiated cells to 91-95%, compared to 37-70% with IL-3 alone. In addition, the number of apoptotic cells using the annexin V method increased after 14 days from 5.1% with IL-3 to 17.1% with IL-3 + ATRA and by the TUNEL in situ method from 10-26% to 60-95%, respectively. This study demonstrates that ATRA consistently enhances the growth of myeloid progenitors from CD34+ cells. This effect is dependent on the stimulating cytokine, suggesting the myeloid cells responding to ATRA are the less mature CFU-GMs that are targets of IL-3 and GM-CSF and not the G-CSF-responding mature progenitors. The growth stimulation by ATRA and IL-3 is also associated with granulocyte differentiation and increased apoptosis. These studies further suggest a potential role of pharmacological doses of ATRA on the development of normal human hematopoietic cells.