Three-Year Outcomes in Recipients of Mismatched Unrelated Bone Marrow Donor Transplants Using Post-Transplantation Cyclophosphamide: Follow-Up from a National Marrow Donor Program-Sponsored Prospective Clinical Trial

The use of post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis has resulted in reductions in GVHD and improved outcomes in allogeneic hematopoietic cell transplantation (HCT) using HLA-mismatched related donors. We report the 3-year outcomes of the first multicenter prospective clinical trial using PTCy in the setting of mismatched unrelated donor (MMUD) bone marrow HCT. The study enrolled 80 patients, treated with either myeloablative conditioning (MAC; n = 40) or reduced-intensity conditioning (RIC; n = 40), with the primary endpoint of 1-year overall survival (OS). The median follow-up for this study was 34 months (range, 12 to 46 months) in the RIC group and 36 months (range, 18 to 49 months) in the MAC group. Three-year OS and nonrelapse mortality were 70% and 15%, respectively, in the RIC group and 62% and 10% in the MAC group. No GVHD was reported after 1 year. The incidence of relapse was 29% in the RIC group and 51% in the MAC group. OS did not differ based on HLA match grade (63% in the 7/8 strata and 71% in the 4 to 6/8 strata). These encouraging outcomes, which were sustained for 3 years post-HCT, support the continued exploration of MMUD HCT using a PTCy platform. Important future areas to address include relapse reduction and furthering our understanding of optimal donor selection based on HLA and non-HLA factors.

Effect of time to relapse on overall survival in patients with mantle cell lymphoma following autologous haematopoietic cell transplantation

In young and fit patients with mantle cell lymphoma (MCL), intensive induction therapy followed by a consolidative autologous haematopoietic cell transplant (autoHCT) is the standard of care in the front-line setting. Recently, time-to-event analysis has emerged as an important risk assessment tool in lymphoma, though its impact in MCL is not well defined. We utilized the Center for International Blood and Marrow Transplant Research database to evaluate the effect of post-autoHCT time to relapse on overall survival (OS) over time in 461 patients who underwent autoHCT within 12 months of MCL diagnosis. On multivariate analysis, the impact of relapse on OS was greatest at the six-month [hazard ratio (HR) = 7·68], 12-month (HR = 6·68), and 18-month (HR = 5·81) landmark timepoints. Using a dynamic landmark model we demonstrate that adjusted OS at five years following each landmark timepoint improved with time for relapsing and non-relapsing patients. Furthermore, early relapse (<18 months) following autoHCT defines a high-risk group with inferior post-relapse OS. This retrospective analysis highlights the impact of time to relapse on OS in MCL patients undergoing up-front autoHCT and emphasizes the need to consider novel therapeutic approaches for patients suffering early relapse.

National Marrow Donor Program-Sponsored Multicenter, Phase II Trial of HLA-Mismatched Unrelated Donor Bone Marrow Transplantation Using Post-Transplant Cyclophosphamide

PURPOSE

Hematopoietic cell transplantation (HCT) is curative for hematologic disorders, but outcomes are historically inferior when using HLA-mismatched donors. Despite unrelated donor registries listing > 38 million volunteers, 25%-80% of US patients lack an HLA-matched unrelated donor, with significant disparity across ethnic groups. We hypothesized that HCT with a mismatched unrelated donor (MMUD) using post-transplant cyclophosphamide (PTCy), a novel strategy successful in overcoming genetic disparity using mismatched related donors, would be feasible and increase access to HCT.

PATIENTS AND METHODS

We performed a prospective phase II study of MMUD bone marrow HCT with PTCy for patients with hematologic malignancies. The primary end point was 1-year overall survival (OS), hypothesized to be 65% or better. 80 patients enrolled at 11 US transplant centers (December 2016-March 2019). Following myeloablative or reduced-intensity conditioning-based HCT, patients received PTCy on days +3, +4, with sirolimus and mycophenolate mofetil starting on day +5. We compared outcomes to Center for International Blood and Marrow Transplant Research contemporary controls receiving PTCy.

RESULTS

Notably, 48% of patients enrolled were ethnic minorities. 39% of pairs were matched for 4-6 out of 8 HLA alleles. The primary end point was met, with 1-year OS of 76% (90% CI, 67.3 to 83.3) in the entire cohort, and 72% and 79% in the myeloablative and reduced-intensity conditioning strata, respectively. Secondary end points related to engraftment and graft-versus-host-disease were reached. Multivariate analysis comparing the study group with other mismatched HCT controls found no significant differences in OS.

CONCLUSION

Our prospective study demonstrates the feasibility and effectiveness of HCT with an MMUD in the setting of PTCy. Remarkably, nearly half of the study participants belonged to an ethnic minority population, suggesting this approach may significantly expand access to HCT.

Related peripheral blood stem cell donors experience more severe symptoms and less complete recovery at one year compared to unrelated donors

Unlike unrelated donor registries, transplant centers lack uniform approaches to related donor assessment and deferral. To test whether related donors are at increased risk for donation-related toxicities, we conducted a prospective observational trial of 11,942 related and unrelated donors aged 18-60 years. Bone marrow (BM) was collected at 37 transplant and 78 National Marrow Donor Program centers, and peripheral blood stem cells (PBSC) were collected at 42 transplant and 87 unrelated donor centers in North America. Possible presence of medical comorbidities was verified prior to donation, and standardized pain and toxicity measures were assessed pre-donation, peri-donation, and one year following. Multivariate analyses showed similar experiences for BM collection in related and unrelated donors; however, related stem cell donors had increased risk of moderate [odds ratios (ORs) 1.42; P<0.001] and severe (OR 8.91; P<0.001) pain and toxicities (OR 1.84; P<0.001) with collection. Related stem cell donors were at increased risk of persistent toxicities (OR 1.56; P=0.021) and non-recovery from pain (OR 1.42; P=0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors reporting grade ≥2 pain had significant decreases in Health-Related Quality of Life (HR-QoL) scores at one month and one year post donation (P=0.004). In conclusion, related PBSC donors with comorbidities are at increased risk for pain, toxicity, and non-recovery at one year after donation. Risk profiles described in this study should be used for donor education, planning studies to improve the related donor experience, and decisions regarding donor deferral. Registered at clinicaltrials.gov identifier:00948636.

Effect of Aging and Predonation Comorbidities on the Related Peripheral Blood Stem Cell Donor Experience: Report from the Related Donor Safety Study

The development of reduced-intensity approaches for allogeneic hematopoietic cell transplantation has resulted in growing numbers of older related donors (RDs) of peripheral blood stem cells (PBSCs). The effects of age on donation efficacy, toxicity, and long-term recovery in RDs are poorly understood. To address this we analyzed hematologic variables, pain, donation-related symptoms, and recovery in 1211 PBSC RDs aged 18 to 79 enrolled in the Related Donor Safety Study. RDs aged > 60 had a lower median CD34+ level before apheresis compared with younger RDs (age > 60, 59 × 106/L; age 41 to 60, 81 × 106/L; age 18 to 40, 121 × 106/L; P < .001). This resulted in older donors undergoing more apheresis procedures (49% versus 30% ≥ 2 collections, P < .001) and higher collection volumes (52% versus 32% > 24 L, P < .001), leading to high percentages of donors aged > 60 with postcollection thrombocytopenia <50 × 109/L (26% and 57% after 2 and 3days of collection, respectively). RDs aged 18 to 40 had a higher risk of grades 2 to 4 pain and symptoms pericollection, but donors over age 40 had more persistent pain at 1, 6, and 12 months (odds ratio [OR], 1.7; P = 0.02) and a higher rate of nonrecovery to predonation levels (OR, 1.7; P = .01). Donors reporting comorbidities increased significantly with age, and those with comorbidities that would have led to deferral by National Marrow Donor Program unrelated donor standards had an increased risk for persistent grades 2 to 4 pain (OR, 2.41; P < .001) and failure to recover to predonation baseline for other symptoms (OR, 2.34; P = .004). This information should be used in counseling RDs regarding risk and can assist in developing practice approaches aimed at improving the RD experience for high-risk individuals.

The influence of lymphoid reconstitution kinetics on clinical outcomes in allogeneic stem cell transplantation

Lymphoid recovery following myeloablative stem cell transplantation (SCT) displays a logistic pattern of exponential growth followed by a plateau. Within this logistic framework, lymphoid recovery is characterized by the parameters R (slope of ascent), a (time of maximal rate of ascent) and K (plateau), the 'steady-state' lymphocyte count. A retrospective analysis of allogeneic SCT performed from 2008 to 2013 was undertaken to compare lymphoid recovery and clinical outcomes in 131 patients with acute myelogenous leukemia, acute lymphocytic leukemia, and myelodysplastic syndromes. Using Prism software, a logistic curve was successfully fit to the absolute lymphocyte count recovery in all patients. Patients were classified according to the magnitude and rate of lymphoid recovery; pattern A achieved an absolute lymphocyte counts (ALC) of >1000/μL by day 45, pattern B an ALC 500 < x < 1000/μL, and pattern C an ALC <500/μL. Pattern A was characterized by a higher mean K (p < .0001) compared with patterns B and C. Patients with patterns B and C were more likely to have mixed T cell chimerism at 90 d following SCT (p = .01). There was a trend towards improved survival (and relapse-free survival) in those with pattern A and B at 1 year compared to pattern C (p = .073). There was no difference in cGVHD (p = .42) or relapse (p = .45) between pattern types. Cytomegalovirus (CMV), aGVHD, and all relapse were heralded by deviation from logistic behavior. Pattern C patients were more likely to require donor lymphocyte infusion (DLI) (p = .017). Weaning of tacrolimus post-transplant was associated with a second, separate logistic expansion in some patients. This study demonstrated that lymphoid reconstitution follows a prototypical logistic recovery and that pattern observed correlates with T cell chimerism and need for DLI, and may influence survival.

Plerixafor Plus Granulocyte Colony-Stimulating Factor for Patients with Non-Hodgkin Lymphoma and Multiple Myeloma: Long-Term Follow-Up Report

The purpose of this report is to analyze long-term clinical outcomes of patients exposed to plerixafor plus granulocyte colony-stimulating factor (G-CSF) for stem cell mobilization. This was a study of patients with non-Hodgkin lymphoma (NHL; n = 167) and multiple myeloma (MM; n = 163) who were enrolled in the long-term follow-up of 2 pivotal phase III studies (NCT00741325 and NCT00741780) of 240 µg/kg plerixafor plus 10 µg/kg G-CSF, or placebo plus 10 µg/kg G-CSF to mobilize and collect CD34⁺ cells for autologous hematopoietic stem cell transplantation. Overall survival (OS) and progression-free survival (PFS) were evaluated over a 5-year period following the first dose of plerixafor or placebo. The probability of OS was not significantly different in patients with NHL or MM treated with plerixafor or placebo (NHL: 64%; 95% confidence interval [CI], 56% to 71% versus 56%; 95% CI, 44% to 67%, respectively; MM: 64%; 95% CI, 54% to 72% versus 64%; 95% CI, 53% to 73%, respectively). In addition, there was no statistically significant difference in the probability of PFS over 5 years between treatment groups in patients with NHL (50%; 95% CI, 44% to 67% for plerixafor versus 43%; 95% CI, 31% to 54% for placebo) or those with MM (17%; 95% CI, 10% to 24% for plerixafor versus 30%; 95% CI, 21% to 40% for placebo). In this long-term follow-up study, the addition of plerixafor to G-CSF for stem cell mobilization did not affect 5-year survival in patients with NHL or patients with MM.

Predictive models for ocular chronic graft-versus-host disease diagnosis and disease activity in transplant clinical practice

Ocular chronic graft-versus-host disease is one of the most bothersome common complications following allogeneic hematopoietic stem cell transplantation. The National Institutes of Health Chronic Graft-versus-Host Disease Consensus Project provided expert recommendations for diagnosis and organ severity scoring. However, ocular chronic graft-versus-host disease can be diagnosed only after examination by an ophthalmologist. There are no currently accepted definitions of ocular chronic graft-versus-host disease activity. The goal of this study was to identify predictive models of diagnosis and activity for use in clinical transplant practice. A total of 210 patients with moderate or severe chronic graft-versus-host disease were enrolled in a prospective, cross-sectional, observational study (clinicaltrials.gov identifier: 00092235). Experienced ophthalmologists determined presence of ocular chronic graft-versus-host disease, diagnosis and activity. Measures gathered by the transplant clinician included Schirmer's tear test and National Institutes of Health 0-3 Eye Score. Patient-reported outcome measures were the ocular subscale of the Lee Chronic Graft-versus-Host Disease Symptom Scale and Chief Eye Symptom Intensity Score. Altogether, 157 (75%) patients were diagnosed with ocular chronic graft-versus-host disease; 133 of 157 patients (85%) had active disease. In a multivariable model, the National Institutes of Health Eye Score (P<0.0001) and Schirmer's tear test (P<0.0001) were independent predictors of ocular chronic graft-versus-host disease (sensitivity 93.0%, specificity 92.2%). The Lee ocular subscale was the strongest predictor of active ocular chronic graft-versus-host disease (P<0.0001) (sensitivity 68.5%, specificity 82.6%). Ophthalmology specialist measures that were most strongly predictive of diagnosis in a multivariate model were Oxford grand total staining (P<0.0001) and meibomian score (P=0.027). These results support the use of selected transplant clinician- and patient-reported outcome measures for ocular chronic graft-versus-host disease screening when providing care to allogeneic hematopoietic stem cell transplantation survivors with moderate to severe chronic graft-versus-host disease. Prospective studies are needed to determine if the Lee ocular subscale demonstrates adequate responsiveness as a disease activity outcome measure.

Stem cell transplantation as a dynamical system: are clinical outcomes deterministic?

Outcomes in stem cell transplantation (SCT) are modeled using probability theory. However, the clinical course following SCT appears to demonstrate many characteristics of dynamical systems, especially when outcomes are considered in the context of immune reconstitution. Dynamical systems tend to evolve over time according to mathematically determined rules. Characteristically, the future states of the system are predicated on the states preceding them, and there is sensitivity to initial conditions. In SCT, the interaction between donor T cells and the recipient may be considered as such a system in which, graft source, conditioning, and early immunosuppression profoundly influence immune reconstitution over time. This eventually determines clinical outcomes, either the emergence of tolerance or the development of graft versus host disease. In this paper, parallels between SCT and dynamical systems are explored and a conceptual framework for developing mathematical models to understand disparate transplant outcomes is proposed.

Effectiveness and toxicity of high-dose cyclophosphamide in obese versus non-obese patients receiving allogeneic hematopoietic stem cell transplant

PURPOSE

To determine if there is a difference in toxicity and effectiveness between obese and non-obese patients who receive high-dose cyclophosphamide (Cy) prior to allogeneic hematopoietic stem cell transplant (allo-HCT).

METHODS

Patients were included in this study if they were at least 18 years of age and received high-dose Cy in combination with total body irradiation (CyTBI) or busulfan (BuCy) prior to allo-HCT between 1 January 2008 and 29 February 2012. The primary endpoint was the difference in overall toxicity between obese and non-obese patients. Secondary objectives examined differences in effectiveness between groups assessed by relapse at day +100, relapse at 1 year, death at 1 year, chimerisms at days +30, +60, and +90, and incidence of acute graft versus host disease (aGVHD).

RESULTS

Sixty-one patients met the inclusion criteria, 28 obese and 33 non-obese. Overall toxicity was greater in obese patients compared to non-obese patients (82% vs. 52%, OR 4.3 [95% CI 1.3-14.1]; p = 0.01), which was driven by a greater incidence of renal dysfunction (79% vs. 48%, OR 3.9 [95% CI 1.3-12.1]; p = 0.02). There were no differences in rates of grade 3 or 4 toxicity, hepatic dysfunction, or any measure of effectiveness between groups.

CONCLUSION

Obese patients receiving high-dose Cy and allo-HCT are at increased risk for toxicity, although there appears to be no difference in the rate of relapse or survival between obese and non-obese patients.

Improved survival after transplantation of more donor plasmacytoid dendritic or naïve T cells from unrelated-donor marrow grafts: results from BMTCTN 0201

PURPOSE

To characterize relationships between specific immune cell subsets in bone marrow (BM) or granulocyte colony-stimulating factor-mobilized peripheral blood (PB) stem cells collected from unrelated donors and clinical outcomes of patients undergoing transplantation in BMTCTN 0201.

PATIENTS AND METHODS

Fresh aliquots of 161 BM and 147 PB stem-cell allografts from North American donors randomly assigned to donate BM or PB stem cells and numbers of transplanted cells were correlated with overall survival (OS), relapse, and graft-versus-host disease (GvHD).

RESULTS

Patients with evaluable grafts were similar to all BMTCTN 0201 patients. The numbers of plasmacytoid dendritic cells (pDCs) and naïve T cells (Tns) in BM allografts were independently associated with OS in multivariable analyses including recipient and donor characteristics, such as human leukocyte antigen mismatch, age, and use of antithymocyte globulin. BM recipients of > median number of pDCs, naïve CD8(+) T cells (CD8Tns), or naïve CD4(+) T cells (CD4Tns) had better 3-year OS (pDCs, 56% v 35%; P = .025; CD8Tns, 56% v 37%; P = .012; CD4Tns, 55% v 37%; P = .009). Transplantation of more BM Tns was associated with less grade 3 to 4 acute GvHD but similar rates of relapse. Transplantation of more BM pDCs was associated with fewer deaths resulting from GvHD or from graft rejection. Analysis of PB grafts did not identify a donor cell subset significantly associated with OS, relapse, or GvHD.

CONCLUSION

Donor immune cells in BM but not PB stem-cell grafts were associated with survival after unrelated-donor allogeneic hematopoietic stem-cell transplantation. The biologic activity of donor immune cells in allogeneic transplantation varied between graft sources. Donor grafts with more BM-derived Tns and pDCs favorably regulated post-transplantation immunity in allogeneic hematopoietic stem-cell transplantation.

Autologous transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia achieves outcomes similar to allogeneic transplantation: results of CALGB Study 10001 (Alliance)

Allogeneic stem cell transplantation is the standard approach to Philadelphia chromosome positive acute lymphoblastic leukemia. We hypothesized that imatinib plus sequential chemotherapy will result in significant leukemia cell cytoreduction in patients with Philadelphia chromosome positive acute lymphoblastic leukemia, allowing collection of normal hematopoietic stem cells uncontaminated by residual BCR/ABL1(+) lymphoblasts and thus reduce the likelihood of relapse after autologous stem cell transplantation for patients under 60 years of age without sibling donors. We enrolled 58 patients; 19 underwent autologous and 15 underwent allogeneic stem cell transplantation on study. Imatinib plus sequential chemotherapy resulted in reverse-transcriptase polymerase chain reaction-negative stem cells in 9 patients and remained minimally positive in 4 (6 were not evaluable). Overall survival (median 6.0 years vs. not reached) and disease-free survival (median 3.5 vs. 4.1 years) were similar between those who underwent autologous and those who underwent allogeneic stem cell transplantation. We conclude that autologous stem cell transplantation represents a safe and effective alternative for allogeneic stem cell transplantation in Philadelphia chromosome positive acute lymphoblastic leukemia patients without sibling donors (clinicaltrials.gov identifier:00039377).

Peripheral-blood stem cells versus bone marrow from unrelated donors

BACKGROUND

Randomized trials have shown that the transplantation of filgrastim-mobilized peripheral-blood stem cells from HLA-identical siblings accelerates engraftment but increases the risks of acute and chronic graft-versus-host disease (GVHD), as compared with the transplantation of bone marrow. Some studies have also shown that peripheral-blood stem cells are associated with a decreased rate of relapse and improved survival among recipients with high-risk leukemia.

METHODS

We conducted a phase 3, multicenter, randomized trial of transplantation of peripheral-blood stem cells versus bone marrow from unrelated donors to compare 2-year survival probabilities with the use of an intention-to-treat analysis. Between March 2004 and September 2009, we enrolled 551 patients at 48 centers. Patients were randomly assigned in a 1:1 ratio to peripheral-blood stem-cell or bone marrow transplantation, stratified according to transplantation center and disease risk. The median follow-up of surviving patients was 36 months (interquartile range, 30 to 37).

RESULTS

The overall survival rate at 2 years in the peripheral-blood group was 51% (95% confidence interval [CI], 45 to 57), as compared with 46% (95% CI, 40 to 52) in the bone marrow group (P=0.29), with an absolute difference of 5 percentage points (95% CI, -3 to 14). The overall incidence of graft failure in the peripheral-blood group was 3% (95% CI, 1 to 5), versus 9% (95% CI, 6 to 13) in the bone marrow group (P=0.002). The incidence of chronic GVHD at 2 years in the peripheral-blood group was 53% (95% CI, 45 to 61), as compared with 41% (95% CI, 34 to 48) in the bone marrow group (P=0.01). There were no significant between-group differences in the incidence of acute GVHD or relapse.

CONCLUSIONS

We did not detect significant survival differences between peripheral-blood stem-cell and bone marrow transplantation from unrelated donors. Exploratory analyses of secondary end points indicated that peripheral-blood stem cells may reduce the risk of graft failure, whereas bone marrow may reduce the risk of chronic GVHD. (Funded by the National Heart, Lung, and Blood Institute-National Cancer Institute and others; ClinicalTrials.gov number, NCT00075816.).

Epigenetic induction of adaptive immune response in multiple myeloma: sequential azacitidine and lenalidomide generate cancer testis antigen-specific cellular immunity

Patients with multiple myeloma (MM) undergoing high dose therapy and autologous stem cell transplantation (SCT) remain at risk for disease progression. Induction of the expression of highly immunogenic cancer testis antigens (CTA) in malignant plasma cells in MM patients may trigger a protective immune response following SCT. We initiated a phase II clinical trial of the DNA hypomethylating agent, azacitidine (Aza) administered sequentially with lenalidomide (Rev) in patients with MM. Three cycles of Aza and Rev were administered and autologous lymphocytes were collected following the 2nd and 3rd cycles of Aza-Rev and cryopreserved. Subsequent stem cell mobilization was followed by high-dose melphalan and SCT. Autologous lymphocyte infusion (ALI) was performed in the second month following transplantation. Fourteen patients have completed the investigational therapy; autologous lymphocytes were collected from all of the patients. Thirteen patients have successfully completed SCT and 11 have undergone ALI. Six patients tested have demonstrated CTA up-regulation in either unfractionated bone marrow (n = 4) or CD138+ cells (n = 2). CTA (CTAG1B)-specific T cell response has been observed in all three patients tested and persists following SCT. Epigenetic induction of an adaptive immune response to cancer testis antigens is safe and feasible in MM patients undergoing SCT.

Favorable outcomes in patients with high donor-derived T cell count after in vivo T cell-depleted reduced-intensity allogeneic stem cell transplantation

Patients with hematologic malignancies were conditioned using a rabbit antithymocyte globulin-based reduced-intensity conditioning regimen for allogeneic stem cell transplantation. Donor-derived CD3(+) cell count (ddCD3), a product of CD3(+) cell chimerism and absolute CD3(+) cell count, when <110/μL at 8 weeks post-stem cell transplantation predicted a high risk of sustained mixed chimerism and relapse. Alternatively, patients with a higher ddCD3 developed graft-versus-host disease more frequently, and when partially chimeric, had higher rates of conversion to full donor chimerism after withdrawal of immunosuppression. Early data from our small cohort of patients indicate that ddCD3 at 8 weeks may be used to guide decisions regarding withdrawal of immunosuppression and administration of donor lymphocyte infusion in partially T cell-depleted reduced-intensity regimens.

Fludarabine-based conditioning for marrow transplantation from unrelated donors in severe aplastic anemia: early results of a cyclophosphamide dose deescalation study show life-threatening adverse events at predefined cyclophosphamide dose levels

Excessive adverse events were encountered in a Phase I/II study of cyclophosphamide (CY) dose deescalation in a fludarabine-based conditioning regimen for bone marrow transplantation from unrelated donors in patients with severe aplastic anemia. All patients received fixed doses of antithymocyte globulin, fludarabine, and low-dose total body irradiation. The starting CY dose was 150 mg/kg, with deescalation to 100 mg/kg, 50 mg/kg, or 0 mg/kg. CY dose level 0 mg/kg was closed due to graft failure in 3 of 3 patients. CY dose level 150 mg/kg was closed due to excessive organ toxicity (n = 6) or viral pneumonia (n = 1), resulting in the death of 7 of 14 patients. CY dose levels 50 and 100 mg/kg remain open. Thus, CY at doses of 150 mg/kg in combination with total body irradiation (2 Gy), fludarabine (120 mg/m(2)), and antithymocyte globulin was associated with excessive organ toxicity.

Successful stem cell remobilization using plerixafor (mozobil) plus granulocyte colony-stimulating factor in patients with non-hodgkin lymphoma: results from the plerixafor NHL phase 3 study rescue protocol

In a phase 3 multicenter, randomized, double-blinded, placebo-controlled study of 298 patients with non-Hodgkin lymphoma (NHL), granulocyte colony-stimulating factor (G-CSF) plus plerixafor increased the proportion of patients who mobilized >or=5 x 10(6) CD34(+) hematopoietic stem cells (HSCs)/kg compared with placebo plus G-CSF (P < .001). Patients in either study arm who failed mobilization (< 0.8 x 10(6) CD34(+) cells/kg in 2 collections or <2 x 10(6) CD34(+) cells/kg in 4 collections) were eligible to enter the opened-label rescue protocol. Following a 7-day minimum rest period, these patients received G-CSF (10 microg/kg/day) for 4 days, followed by daily plerixafor (0.24 mg/kg) plus G-CSF and apheresis for up to 4 days. Of the 68 patients failing initial mobilization (plerixafor, n = 11; placebo, n = 57), 62 patients (91%) entered the rescue procedure (plerixafor, n = 10; placebo, n = 52). Four of 10 patients (40%) from the plerixafor group and 33 of 52 (63%) from the placebo group mobilized sufficient CD34(+) cells (>or= 2 x 10(6) cells/kg) for transplantation from the rescue mobilization alone (P = .11). Engraftment of neutrophils (11 days) and platelets (20 days) was similar to that in patients who did not fail initial mobilization, and all patients had durable grafts at the 12-month follow-up. Common plerixafor-related adverse events (AEs) included mild gastrointestinal (GI) effects and injection site reactions. There were no drug-related serious AEs. These data support that plerixafor plus G-CSF can safely and effectively remobilize patients with NHL who have failed previous mobilization.

A preliminary investigation into the action of anagrelide: Thrombopoietin–c-Mpl receptor interactions

OBJECTIVE

Many studies have validated the clinical efficacy of anagrelide to reduce platelet counts in thrombocythemic conditions. With the ability to support human megakaryopoiesis in vitro using thrombopoietin (TPO), specific investigation of changes in platelet levels can be carried out in human systems. Using CD34(+) stem cells and murine BaF3 cells transfected with the human or murine TPO receptor, c-Mpl (BaF3mpl), the effect of anagrelide on cell differentiation, proliferation, and signaling was examined in the presence of TPO.

METHODS

Inhibition of TPO-mediated cell differentiation by anagrelide was evaluated by fluorescein-activated cell sorting analysis. Cell proliferation was monitored by 3-(4,5-dimethylthiazol-2-yl)-5-3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays. Effect of anagrelide on TPO-mediated phosphotyrosine (pTyr) activity was examined by Western analysis of whole cell lysates.

RESULTS

In the presence of TPO, anagrelide reduced the number of CD41(+) cells without a reduction in the total mononuclear cell number in a dose-dependent manner. Growth inhibition was also observed in BaF3 cells transfected with human c-Mpl. Anagrelide also reduced TPO-specific pTyr activity in a species-specific manner. No inhibitory effect could be demonstrated with interleukin-3 stimulation.

CONCLUSION

Parallel dose-response effects were found in both CD41(+) number and TPO-specific pTyr activity. These results suggest that anagrelide reduces TPO-mediated megakaryocyte proliferation of CD34(+) cells through a mechanism that leads to inhibition of intracellular signaling events. Furthermore, data also suggest that it is a species-specific effect, with no inhibitory activity against the murine receptor. Because there is a less than 10% difference in DNA sequence homology between human and murine receptors, the difference in sequence-specific activity must reside in these amino acid differences.

The use of AMD3100 plus G-CSF for autologous hematopoietic progenitor cell mobilization is superior to G-CSF alone

Hematopoietic progenitor cells (HPCs) traffic to and are retained in the marrow through the trophic effects of the chemokine stromal cell-derived factor-1alpha (SDF-1alpha) binding to its receptor, CXC chemokine receptor 4 (CXCR4). AMD3100 reversibly inhibits SDF-1alpha/CXCR4 binding, and AMD3100 administration mobilizes CD34(+) cells into the circulation. We therefore tested the hypotheses that the combination of AMD3100 plus granulocyte colony-stimulating factor (G-CSF) (hereafter A + G) would be superior to G-CSF alone (hereafter G) in mobilizing hematopoietic progenitor cells (HPCs) and that A + G-mobilized cells would engraft as well as G-mobilized cells. The primary objective was to determine whether patients mobilized more progenitor cells per unit of blood volume of apheresis after A + G administration versus G alone. Secondary objectives were to determine whether patients mobilized with A + G compared with G alone required fewer apheresis procedures to reach the target level at least 5 x 10(6) CD34(+) cells/kg for transplantation and to determine whether patients mobilized with A + G had at least a 90% success rate of autologous transplantation as assessed by neutrophil engraftment by day 21. Each patient served as his or her own control in a sequential mobilization design. All study objectives were met without significant toxicity. The results demonstrate that the combination of A + G is generally safe, effective, and superior to G alone for autologous HPC mobilization.

Transplant strategies for idiopathic myelofibrosis

Idiopathic myelofibrosis (IMF) is a clonal stem cell disorder and is one of the four major myeloproliferative disorders, which include essential thrombocythemia (ET), polycythemia vera (PV), and chronic myelogenous leukemia (CML). Patients may be asymptomatic at the early stages, but later progress to marrow fibrosis, splenomegaly with pancytopenia leading to anemia, and other constitutional symptoms. Most of the care available is supportive and only palliates the constitutional symptoms. Prognosis for these patients is dependent on karyotype, hemoglobin count, and age. Stem cell transplantation is the only curative therapy, which results in eradication of the stem cell clone, with the cessation of extramedullary hematopoiesis and resolution of marrow fibrosis and its sequelae. Stem cell replacement therapy using either autologous or allogeneic stem cells has been attempted in small populations of patients with variable benefit. A nonmyeloablative approach has shown promise in a very small number of patients, but additional investigation is required for the ideal management of these patients.

Na+-H+ exchange activity in taste receptor cells

mRNA for two Na(+)-H(+)-exchanger isoforms 1 and 3 (NHE-1 and NHE-3) was detected by RT-PCR in fungiform and circumvallate taste receptor cells (TRCs). Anti-NHE-1 antibody binding was localized to the basolateral membranes, and the anti-NHE-3 antibody was localized in the apical membranes of fungiform and circumvallate TRCs. In a subset of TRCs, NHE-3 immunoreactivity was also detected in the intracellular compartment. For functional studies, an isolated lingual epithelium containing a single fungiform papilla was mounted with apical and basolateral sides isolated and perfused with nominally CO(2)/HCO(3)(-)-free physiological media (pH 7.4). The TRCs were monitored for changes in intracellular pH (pH(i)) and Na(+) ([Na(+)](i)) using fluorescence ratio imaging. At constant external pH, 1) removal of basolateral Na(+) reversibly decreased pH(i) and [Na(+)](i); 2) HOE642, a specific blocker, and amiloride, a nonspecific blocker of basolateral NHE-1, attenuated the decrease in pH(i) and [Na(+)](i); 3) exposure of TRCs to basolateral NH(4)Cl or sodium acetate pulses induced transient decreases in pH(i) that recovered spontaneously to baseline; 4) pH(i) recovery was inhibited by basolateral amiloride, 5-(N-methyl-N-isobutyl)-amiloride (MIA), 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), HOE642, and by Na(+) removal; 5) HOE642, MIA, EIPA, and amiloride inhibited pH(i) recovery with K(i) values of 0.23, 0.46, 0.84, and 29 microM, respectively; and 6) a decrease in apical or basolateral pH acidified TRC pH(i) and inhibited spontaneous pH(i) recovery. The results indicate the presence of a functional NHE-1 in the basolateral membranes of TRCs. We hypothesize that NHE-1 is involved in sour taste transduction since its activity is modulated during acid stimulation.

Mycotic osteomyelitis due to Scedosporium Apiospermum: MR imaging-pathologic correlation

Mycotic osteomyelitis is rare and occurs in immunocompromised patients after inoculation of the pathogen at a penetrating trauma site. Mycotic osteomyelitis due to Scedosporium Apiospermum is extremely rare, with only 13 cases of septic arthritis reported previously. Ours is only the third case of S. apiospermum osteomyelitis in an immunocompromised patient and the only patient with a histopathologic diagnosis from an amputation specimen. Recognition of this pathogen may be delayed due to insidious onset and negative joint fluid cultures, often requiring synovial or bone biopsies to establish the diagnosis. Delay in appropriate treatment may result in disseminating infection or even death.

Granulomatous myositis: a manifestation of chronic graft-versus-host disease

A case of granulomatous myositis as a manifestation of chronic graft-versus-host disease is presented. The clinical presentation, MR imaging appearances, pathologic features and excellent response to treatment with immunosuppression are described. To the best of our knowledge, based on a world literature search, this is the first report of graft-versus-host disease presenting as granulomatous polymyositis.,

PEPCK mRNA localization in proximal tubule and gene regulation during metabolic acidosis

To identify the nephron segments expressing PEPCK in control and acidotic conditions, PEPCK mRNA was localized in rat kidney using the technique of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected S1 S2, and S3 segments of the rat proximal tubule. In controls, the number of tubules expressing PEPCK mRNA was greatest in the S3 segment, moderate in the S2 segment, and least in the S1 segment of the proximal tubule. After NH4Cl feeding, strong signals for PEPCK mRNA were detected in all three proximal tubule segments. In situ hybridization demonstrated expression of PEPCK mRNA only in the medullary rays in controls. After NH4Cl, PEPCK mRNA was expressed throughout the cortex, confirming the RT-PCR results. These data demonstrate the ability of the rat kidney cortex to modulate the expression of PEPCK mRNA during metabolic acidosis by recruitment of additional cells in the proximal nephrons. Studies with cultured LLC-PK1-F+ cells indicated that increased PEPCK gene transcription at acid pH required a cis-acting element (enhancer) in the more distal 5' flanking region of the promoter.

Five days of cefprozil versus 10 days of clarithromycin in the treatment of an acute exacerbation of chronic bronchitis

BACKGROUND

Shorter than traditional 7- to 14-day treatment regimens have demonstrated efficacy in treatment of an acute exacerbation of chronic bronchitis (AECB).

OBJECTIVE

Perform a clinical efficacy study comparing 5 days of cefprozil therapy to 10 days of clarithromycin in treating an AECB.

METHODS

A multicenter, randomized, double-blind study comparing efficacy and safety of cefprozil, 500 mg twice daily, for 5 days with clarithromycin, 500 mg twice daily, for 10 days in treatment of 295 subjects with AECB. Concomitantly, among all treated subjects, 39% (115 of 295) had a history of chronic obstructive pulmonary disease/emphysema; 21% (62 of 295) had a history of asthma/reactive airway disease; and 31% (90 of 295) had environmental allergies.

RESULTS

There were no statistically significant differences among clinically evaluable subjects' cure rates; 82% (109 of 133) treated with cefprozil versus 85% (105 of 123) treated with clarithromycin were cured at test-of-cure visit (95% confidence interval, -12.0 to 5.1%). Clinical cure rates at end of study were 80% and 81%, respectively (95% confidence interval, -10.8 to 7.9%). Before treatment, 99% (85 of 86) of Gram-positive organisms isolated were susceptible to cefprozil and 78% (67 of 86) were susceptible to clarithromycin. A total of 84% (96 of 114) of Gram-negative organisms were susceptible to cefprozil and 63% (72 of 114) were susceptible to clarithromycin. Of clinically evaluable Streptococcus pneumoniae-infected subjects, 100% (11 of 11) of cefprozil subjects and 93% (14 of 15) of clarithromycin subjects experienced clinical cure. The most frequently reported adverse effects were nausea, 5% (7 of 150), and diarrhea, 9% (14 of 150), for cefprozil. For clarithromycin, the adverse effects were nausea, 8% (11 of 145); diarrhea, 12% (18 of 145); taste perversion, 8% (11 of 145); and dry mouth, 5% (7 of 145).

CONCLUSIONS

Five days of cefprozil is as effective as 10 days of clarithromycin for treatment of an AECB.

Neuronal nitric oxide synthase: expression in rat parietal cells

Nitric oxide synthases (NOS) are enzymes that catalyze the generation of nitric oxide (NO) from L-arginine and require nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor. At least three isoforms of NOS have been identified: neuronal NOS (nNOS or NOS I), inducible NOS (iNOS or NOS II), and endothelial NOS (eNOS or NOS II). Recent studies implicate NO in the regulation of gastric acid secretion. The aim of the present study was to localize the cellular distribution and characterize the isoform of NOS present in oxyntic mucosa. Oxyntic mucosal segments from rat stomach were stained by the NADPH-diaphorase reaction and with isoform-specific NOS antibodies. The expression of NOS in isolated, highly enriched (>98%) rat parietal cells was examined by immunohistochemistry, Western blot analysis, and RT-PCR. In oxyntic mucosa, histochemical staining revealed NADPH-diaphorase and nNOS immunoreactivity in cells in the midportion of the glands, which were identified as parietal cells in hematoxylin and eosin-stained step sections. In isolated parietal cells, decisive evidence for nNOS expression was obtained by specific immunohistochemistry, Western blotting, and RT-PCR. Cloning and sequence analysis of the PCR product confirmed it to be nNOS (100% identity). Expression of nNOS in parietal cells suggests that endogenous NO, acting as an intracellular signaling molecule, may participate in the regulation of gastric acid secretion.

Comparative safety and efficacy of cefdinir vs amoxicillin/clavulanate for treatment of suppurative acute otitis media in children

OBJECTIVE

Two dosage regimens of cefdinir were compared with amoxicillin/clavulanate for the treatment of suppurative acute otitis media (AOM) in children.

METHODS

This was an investigator-blinded, randomized, comparative, multicenter trial, in which tympanocentesis was performed in 384 patients, ages 6 months to 12 years, who had nonrefractory AOM. Patients were randomized to receive one of three 10-day treatment regimens: cefdinir 14 mg/kg daily (QD; n = 128); cefdinir 7 mg/kg twice a day (BID; n = 128); or amoxicillin/clavulanate 40/10 mg/kg/day divided for use three times a day (TID; n = 128).

RESULTS

Of the 384 enrolled patients 303 were evaluable for clinical efficacy. Clinical success rates were statistically equivalent for the 3 treatment groups at the end of therapy: 85 of 102 (83.3%) for cefdinir QD; 81 of 101 (80.2%) for cefdinir BID; 86 of 100 (86%) for amoxicillin/clavulanate. Of the 197 evaluable patients from whom a susceptible pathogen was recovered, presumptive eradication rates at end of therapy were equivalent: 55 of 65 (84.6%), 54 of 66 (81.8%) and 55 of 66 (83.3%) for cefdinir QD-, cefdinir BID- and amoxicillin/clavulanate-treated patients, respectively. However, presumptive eradication rates for Streptococcus pneumoniae were significantly lower for cefdinir BID (55.2%) than for amoxicillin/clavulanate (89.5%; P = 0.0019) and marginally lower than for cefdinir QD (80%; P = 0.054). Diarrhea was the most common treatment-associated adverse reaction in all groups but was significantly more common in amoxicillin/clavulanate-treated patients (35%) than in patients who had been treated with cefdinir QD (10%, P<0.001) or cefdinir BID (13%, P<0.001).

CONCLUSIONS

A 10-day regimen of cefdinir 14 mg/kg QD or 7 mg/kg BID was as clinically effective overall as a 10-day regimen of amoxicillin/ clavulanate 40/10 mg/kg/day divided TID in the treatment of tympanocentesis-confirmed, nonrefractory AOM in children. These data suggest that cefdinir QD may be a better alternative than cefdinir BID for refractory AOM. Both dosing regimens of cefdinir were associated with significantly fewer gastrointestinal adverse reactions than was amoxicillin/clavulanate.

Clarithromycin in the management of community-acquired pneumonia

OBJECTIVE

To review the epidemiology and diagnosis of community-acquired pneumonia (CAP) and examine factors that influence the choice of empiric antimicrobial therapy.

BACKGROUND

CAP remains a common disease with substantial associated morbidity and mortality. Outpatient management of patients with CAP has become increasingly complex because of the availability of newer antimicrobial agents, evolving patterns of resistance, and the increasing recognition of atypical pathogens. Although Streptococcus pneumoniae remains a commonly encountered pathogen, the development and increasing prevalence of antibiotic resistance has become an area of concern, especially in outpatients. The newer macrolide antimicrobial drugs-clarithromycin and azithromycin-are effective against commonly encountered pathogens, are well tolerated, and have an established tolerability profile, although the low serum levels achieved by azithromycin hinder its use in patients with suspected bacteremia.

METHODS

A MEDLINE search was performed of English-language articles published from 1990 to 2000 on the treatment of CAP. This article reviews the treatment of CAP, with emphasis on the use of clarithromycin.

CONCLUSION

Although laboratory surveillance studies have reported macrolide-resistant S. pneumoniae, recent evidence defining the mechanism of this resistance, coupled with the pharmacokinetic properties of the macrolide agents, suggests that the actual rate of clinical macrolide resistance is low.

A randomized trial of short-course ciprofloxacin, ofloxacin, or trimethoprim/sulfamethoxazole for the treatment of acute urinary tract infection in women. Ciprofloxacin Urinary Tract Infection Group

PURPOSE

Bladder infections are very common in otherwise healthy women, and short-course antimicrobial treatment appears effective for many episodes of cystitis. This study reports the results of short-course ciprofloxacin, ofloxacin, and trimethoprim/sulfamethoxazole therapy.

PATIENTS AND METHODS

We performed a randomized, double-blind study of the efficacy and safety of a 3-day course of oral ciprofloxacin 100 mg twice daily, ofloxacin 200 mg twice daily, or trimethoprim/sulfamethoxazole 160/800 mg twice daily in women with acute, uncomplicated, symptomatic lower urinary tract infection.

RESULTS

A total of 866 patients were enrolled, of whom 688 (79%) were evaluated for the efficacy of treatment (229 treated with ciprofloxacin, 228 treated with trimethoprim/sulfamethoxazole, and 231 treated with ofloxacin). The most frequent reason for exclusion was the failure to identify a pretreatment pathogen. The most commonly isolated pathogen was Escherichia coli (81%). Eradication of the pretreatment pathogen at the end of therapy occurred in 94% of ciprofloxacin, 93% of trimethoprim/sulfamethoxazole, and 97% of ofloxacin-treated patients. At follow-up evaluation at 4 to 6 weeks, recurrence rates (relapse or reinfection) were 11% in the ciprofloxacin, 16% in the trimethoprim/sulfamethoxazole, and 13% in the ofloxacin treatment group. Clinical success at the end of therapy was 93% in the ciprofloxacin, 95% in the trimethoprim/sulfamethoxazole, and 96% in the ofloxacin treatment groups. The frequency of all adverse events was 31% for ciprofloxacin, 41% for trimethoprim/sulfamethoxazole, and 39% for ofloxacin-treated patients (P = 0.03). Premature discontinuation of study drug due to an adverse event was more common in trimethoprim/sulfamethoxazole-treated patients (n = 9) compared with those given ciprofloxacin (n = 2) or ofloxacin (n = 1; P = 0.02).

CONCLUSION

Ciprofloxacin, ofloxacin, and trimethoprim/sulfamethoxazole had similar efficacy when given for 3 days to treat acute, symptomatic, uncomplicated lower urinary tract infection in women.

Development of intralesional therapy with fluorouracil/adrenaline injectable gel for management of condylomata acuminata: two phase II clinical studies

OBJECTIVES

To evaluate a sustained release chemotherapy for treating condylomata acuminata with an injectable gel containing fluorouracil and adrenaline (5-FU/adrenaline gel). Study 1-- To assess contributions of the components of 5-FU/adrenaline gel to efficacy. Study 2--To assess therapeutic contribution of adrenaline and safety and efficacy of the formulations.

DESIGN

Randomised, double blind, placebo controlled studies.

SETTING

Private practices and university clinics in the United States.

PATIENTS

Men and women with new, recurrent, or refractory external condylomata acuminata.

INTERVENTION

Six injections over 8 weeks; follow up visits at weeks 1, 4, 8, and 12.

MAIN OUTCOME MEASURES

EFFICACY

patient/wart response, times to complete response, recurrence rates.

SAFETY

injection reactions, tissue conditions, other adverse events, laboratory studies.

RESULTS

Study 1: 132 evaluable patients. Complete response (CR) rate was highest for the 5-FU/adrenaline gel group, followed by the 5-FU/adrenaline solution group, then the 5-FU gel group. 5-FU, adrenaline, and the collagen gel vehicle (in the presence of 5-FU) significantly affected CR and strongly influenced time to CR. The effects of 5-FU and adrenaline were statistically significant. Cutaneous reactions were mild to moderate. Study 2: 187 evaluable patients. Patients treated with 5-FU/adrenaline gel had a significantly higher CR rate and lower cumulative 90 day recurrence rate than those treated with 5-FU gel without adrenaline. Treatments were generally well tolerated, with only three treatment related, serious adverse events.

CONCLUSION

5-FU/adrenaline gel is safe and efficacious for treatment of condylomata acuminata, and when compared with individual or various combinations of components, this formulation provided the greatest therapeutic advantage.

Intralesional fluorouracil/epinephrine injectable gel for treatment of condylomata acuminata. A phase 3 clinical study

BACKGROUND AND DESIGN

A new intralesional sustained-release chemotherapy is under development as a treatment for condylomata acuminata; it is administered as an injectable gel that consists of fluorouracil and epinephrine with a purified bovine collagen as the gellant (fluorouracil/epinephrine gel). In this randomized, double-blind study, we evaluated the safety and efficacy of this intralesional treatment in 401 patients, using 2 active drug formulations (fluorouracil/epinephrine gel and fluorouracil gel alone) and a placebo. Each lesion was injected once a week for up to 6 weeks, and patients were followed up for 3 months.

RESULTS

A total of 359 patients with 1926 condylomata underwent evaluation. For all lesions treated with fluorouracil/epinephrine gel, the complete response (CR) rate was 77%. For all patients treated with fluorouracil/epinephrine gel, the CR rate was 61%. The fluorouracil/epinephrine gel was significantly more effective (P < .002) in treating condylomata than the fluorouracil gel without epinephrine (CR rate, 43%); both were superior to placebo (CR rate, 5%). At 3 months after completion of treatment, recurrence rates in patients with CRs were as follows: fluorouracil/epinephrine gel group, 50%; fluorouracil gel group, 58%. No clinically significant drug-related systemic reactions occurred. Finally, the type and severity of local tissue reactions of patients with a positive pretreatment collagen skin test result (6/401 [1.5%]) were similar to those of patients with a negative collagen skin test result.

CONCLUSION

The fluorouracil/epinephrine injectable gel is a safe and effective treatment for condylomata acuminata.

Penetration of clarithromycin into middle ear fluid of children with acute otitis media

OBJECTIVE

To determine the steady state plasma and middle ear fluid concentrations of clarithromycin and its metabolite, 14(R)-hydroxyclarithromycin in 32 pediatric patients with acute otitis media.

METHODS

After the sixth dose of a 7.5-mg/kg every-12-h regimen of clarithromycin suspension, tympanocentesis was performed at 2, 4, 8 or 12 hours postdose. Plasma and middle ear fluid samples were assayed for concentrations of clarithromycin and its 14-hydroxy metabolite.

RESULTS

Mean middle ear fluid concentrations ranged from 3.0 to 8.3 micrograms/g during the dosing interval for clarithromycin and from 1.5 to 3.8 micrograms/g for 14(R)-hydroxyclarithromycin. The mean middle ear fluid concentrations were consistently greater than corresponding mean plasma concentrations, which ranged from 0.7 to 3.4 micrograms/ml for clarithromycin and from 0.8 to 1.8 micrograms/ml for 14(R)-hydroxyclarithromycin. The ratios of middle ear fluid to plasma concentration appeared to increase during the dosing interval and were 8.8 and 3.8 for clarithromycin and 14(R)-hydroxyclarithromycin, respectively, 12 h after dosing.

CONCLUSIONS

Multiple oral doses of clarithromycin suspension produced sustained middle ear fluid concentrations of clarithromycin and 14(R)-hydroxyclarithromycin which exceed the minimum inhibitory concentrations of most otic pathogens.

Murine thrombopoietin mRNA levels are modulated by platelet count

The activity of the c-Mpl ligand hematopoietic progenitors meets criteria expected for thrombopoietin (TPO). Bio-assays have shown that blood TPO levels are inversely related to platelet mass. We sought to identify the molecular basis for this regulation. To determine if TPO mRNA levels respond to platelet demand, RNA from selected organs of mice with high, normal or low platelet counts was subjected to semiquantitative reverse transcriptase-polymerase chain reaction. Although no differences in TPO mRNA levels between control and treated mice could be detected in liver or kidney, TPO-specific bands were more intense after 25 to 30 polymerase chain reaction cycles in marrow-derived mRNA from thrombocytopenic mice. The TPO-specific bands were less intense in thrombocytotic mouse marrow and spleen than control mouse marrow and spleen after 30 cycles. These data support the hypothesis that TPO levels are regulated, at least in part, by modulating mRNA levels in response to platelet demand.

Interleukin-4 induces endothelial vascular cell adhesion molecule-1 (VCAM-1) by an NF-kappa b-independent mechanism

While all features of the inflammatory response induced by IL-1 are not observed following IL-4 stimulation, suboptimal concentrations both cytokines result in synergistic VCAM-1 expression in HUVEC. We have shown that, while IL-1 stimulated HUVEC express GM-CSF, tissue factor and VCAM-1, only VCAM-1 is detectable after exposure to IL-4. While kB was found essential for both basal and IL-1-mediated activity of VCAM-1, IL-4 induction was kB-independent. Inducible kB-binding proteins were identified in IL-1-, but not IL-4-stimulated nuclear extracts. Our results indicate that IL-4 exerts its transcriptional effects on the VCAM-1 gene through element(s) which do not require kB.

Comparative efficacy and safety of cefprozil versus penicillin, cefaclor and erythromycin in the treatment of streptococcal pharyngitis and tonsillitis

Cefprozil is a new oral cephalosporin with an enhanced in vitro spectrum of activity that includes group A beta-hemolytic streptococci (GABHS). Four multicenter randomized clinical trials were conducted to compare the clinical efficacy and safety of cefprozil administered once or twice a day for the treatment of mild to moderate GABHS tonsillitis and pharyngitis. A total of 1597 patients were enrolled in the trials. Patient demographics and severity of infection were similar for all treatment groups. In Study 1, cefprozil administered at 20 mg/kg once daily was clinically, in 68 of 76 patients (89%) and bacteriologically, in 66 of 74 patients (89%) superior to penicillin -51 of 69 (74%) and 46 of 69 (67%)--administered three times a day in patients of two to 12 years of age. In Study 2, the patients enrolled were 13 years of age and older, and cefprozil administered at 20 mg/kg once a day had similar clinical (93% vs. 90%) and bacteriological (95% vs. 94%) response rates as cefaclor administered three times a day. Study 3 demonstrated that cefprozil administered twice daily was similar to penicillin given three times a day, the clinical satisfactory response being 164 of 175 (94%) for cefprozil and 146 of 165 (88%) for penicillin. In Study 4, identical clinical and bacteriologic responses (95%) were observed for cefprozil administered once a day and erythromycin ethylsuccinate administered four times a day in children over two years of age. There were no significant differences in the incidence or severity of drug-related adverse events, which, when reported, were mild and transient.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory epithelial cell expression of human transforming growth factor-alpha induces lung fibrosis in transgenic mice

Increased production of EGF or TGF-alpha by the respiratory epithelial cells has been associated with the pathogenesis of various forms of lung injury. Growth factors and cytokines are thought to act locally, via paracrine and autocrine mechanisms, to stimulate cell proliferation and matrix deposition by interstitial lung cells resulting in pulmonary fibrosis. To test whether TGF-alpha mediates pulmonary fibrotic responses, we have generated transgenic mice expressing human TGF-alpha under control of regulatory regions of the human surfactant protein C (SP-C) gene. Human TGF-alpha mRNA was expressed in pulmonary epithelial cells in the lungs of the transgenic mice. Adult mice bearing the SP-C-TGF-alpha transgene developed severe pulmonary fibrosis. Fibrotic lesions were observed in peribronchial, peribronchiolar, and perivascular regions, as well as subjacent to pleural surfaces. Lesions consisted of fibrous tissue that included groups of epithelial cells expressing endogenous SP-C mRNA, consistent with their identification as distal respiratory epithelial cells. Peripheral fibrotic regions consisted of thickened pleura associated with extensive collagen deposition. Alveolar architecture was disrupted in the transgenic mice with loss of alveoli in the lung parenchyma. Pulmonary epithelial cell expression of TGF-alpha in transgenic mice disrupts alveolar morphogenesis and produces fibrotic lesions mediated by paracrine signaling between respiratory epithelial and interstitial cells of the lung.