Infectious complications after allogeneic stem cell transplantation: incidence in matched-related and matched-unrelated transplant settings

BACKGROUND

Bacterial, viral, and fungal pathogens frequently cause severe, life-threatening infections in immunocompromised patients after allogeneic hematopoietic stem cell transplantation (SCT).

OBJECTIVE

To compare the frequency of infections in patients with matched-related (Group A) or with human leukocyte antigen (HLA)-matched-unrelated donors (Group B).

PATIENTS AND METHODS

Patients treated at our transplantation unit between April 2004 and April 2005 were enrolled into this analysis. Documentation comprised demographic data, conditioning treatment, stem cell source, clinical course, as well as microbiological and clinical data and mortality.

RESULTS

We analyzed 59 patients, 22 in Group A and 37 in Group B. Both groups were well balanced regarding demographic data. Diagnoses were acute myeloid leukemia (30 of 59 patients, 50.8%), multiple myeloma (15.2%), acute lymphoblastic leukemia (11.9%), and chronic myeloid leukemia (10.2%). Patients in Group A developed infections in 95.5% of the cases compared with 97.3% in patients in Group B. Most frequently detected pathogens were Staphylococcus species, human herpesvirus-6, and Epstein-Barr virus. Three proven fungal infections were detected in Group A compared with 9 proven fungal infections in Group B. Lung infiltrations were observed in equivalent incidence in both groups. Two years after transplantation, 55.9% of patients were alive (Group A: 68.2%; Group B: 48.6%, not significant).

CONCLUSION

Allogeneic SCT from HLA-matched-unrelated donors does not have a higher infection risk than patients transplanted from matched-related donors.

Pregnancy associated smoking behavior and six year postpartum recall

BACKGROUND

This study examined predictors and behaviors of pregnancy-related smoking among women who belonged to a private health maintenance organization and the recall accuracy of pregnancy-related smoking behaviors after 6-years.

METHODS

A cohort of 725 pregnant women was followed for six years. Major predictors for smoking behavior before, during, and one-year following pregnancy were determined. In addition, accuracy of recall six years postpartum of smoking behavior at the time of pregnancy and one-year postpartum was tested.

RESULTS

Mother's education, asthma status, amount of pre-pregnancy smoking, gravidity, and father's smoking status were important in the prediction of pregnancy associated smoking. Agreement for recall of smoking behavior during pregnancy (6 year recall) and one-year postpartum (5 year recall) were 90% and 91%, respectively.

CONCLUSIONS

Despite potentially adverse outcomes, a proportion of women continue to smoke throughout pregnancy. A number of variables proved to be important predictors of pregnancy associated smoking behavior. These factors should be considered by smoking cessation programs targeting women of reproductive age. Additionally, there was substantial agreement for maternal recall at six years postpartum of smoking behavior at the time of pregnancy and one-year postpartum. This should be considered in retrospective study designs that are primarily based on maternal recall of smoking behaviors before, during, and following pregnancy.

PET FES measures in vivo pharmacodynamics of endocrine therapy

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Background: Many clinical options are available for management of hormone sensitive breast cancer, including agents which lower estrogen levels such as aromatase inhibitors (AIs) and agents with block ligand binding to receptor such as tamoxifen (TAM) or fulvestrant (FUL). Estrogen receptor (ER) function is essential for sensitivity to hormonal manipulation in breast cancer treatment. We and others have previously shown that functional ER imaging using PET FES predicts response to hormonal therapy using a quantitative threshold of SUV >1.5. Herein we report that FES PET provides a unique insight into in vivo pharmacodynamics of ER therapy. We hypothesized that the impact of therapy on estradiol binding to ER, measured by FES PET, differs between AIs and ER antagonists, and that early changes in receptor expression/occupancy show efficacy of drug at the tumor target. Methods: Patients undergoing treatment with AI, TAM, or FUL underwent baseline PET FDG and FES, and follow-up PET FES imaging at 2–8 weeks post initiation of therapy. Results: We observed the following changes in FES uptake on hormonal therapy: Mean percent change in FES SUV were 54% decline for TAM and FUL vs. 14% decline for AI treated patients (p<.001). Patients on TAM showed complete blockade of tumor FES uptake on therapy (5/5 with residual SUV <1.5), whereas patients on FUL had variable uptake and incomplete blockade at tumor sites in most patients (4/11 with residual SUV <1.5) (p < .05 FUL vs. TAM), despite consistent blockade of uterine FES uptake in patients where the uterus was visualized pre-FUL. Patients on AI therapy (n=14) had variable tumor uptake following treatment initiation. Conclusions: PET FES effectively monitors the in vivo activity of therapy. Estrogen blocking therapies result in a greater change in tumoral estradiol binding than in ligand depletion. TAM effectively blocks uptake of FES as would be predicted by the mechanism of action of this agent. However, FUL (while blocking uterine uptake) incompletely blocks tumor uptake, providing a mechanism to explain reduced activity of this agent in some patients. Ongoing analysis is designed to assess whether early changes in FES predict response or clinical benefit.

No significant financial relationships to disclose.

Correlation between immunohistochemical biomarker expression and in vitro drug response factors in stage III-IV ovarian cancer

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Background: The reliability of molecular biomarkers as predictors of treatment outcome remains unclear and, in relation to drug resistance even less is known. Immunohistochemical (IHC) expression of biomarkers and in vitro drug resistance (IVDR) relative to clinical outcome were evaluated in patients with stage III-IV epithelial ovarian cancer (OC) who received combination carboplatin (CAR) plus paclitaxel (TAX) chemotherapy. Methods: We correlated clinical outcome with histopathology and biomarker expression of MIB-1, p53, BCL2, EGFR, ER and PR in 98 OC patients with tumors tested for IVDR by extreme drug resistance (EDR) assay. IVDR was determined following exposures to single agents CAR, cisplatin (CP), TAX, taxotere (TXT), gemcitabine (GCB), topotecan (TP), liposomil doxorubicin, and cytoxan (CT). Percentage cell growth inhibition (PCI) for each drug was compared with PCI from untreated control cultures. Results: Tumors with prior chemotherapy (n=29) were more resistant to CAR (unpaired t-test, p=0.046), and CT (p=0.038), and more sensitive to liposomil doxorubicin (p=0.009), compared to treatment naive tumors (n=53). For 65 tumors, there was a positive relationship between MIB-1 vs p53 (r=0.419; p=0.001), and between ER vs PR (r=0.339; p=0.011). Correlation between biomarkers and drug response showed a significantly inverse relationship between MIB-1 vs liposomil doxorubicin, p53 vs liposomil doxorubicin, EGFR vs CAR, CP, GCB and TAX; and between ER vs TXT and CT, and PR vs CT and TP. With a 53% (33/61) response rate to CAR+TAX, time to progression (TTP) for responders (R) with EGFR+ tumors was longer (median TTP 15.6 mo); and shorter for R with EGFR- tumors (p=0.008). For R and non-R, BCL2+ tumors had longer overall survival (OS) (median OS 23.3 mo; p=0.006). No other significant correlations were seen. Conclusion: Prior chemotherapy increased IVDR to CAR and CT, and increased sensitivity to liposomil doxorubicin. Increased expression of proliferation biomarkers, particularly EGFR, correlated with resistance to several chemotherapeutic agents. EGFR expression in responders was associated with longer TTP. The significance of in vitro correlates of prognostic biomarker expression and IVDR for predicting chemoresistance warrants prospective studies to assess its value in clinical settings.

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Immature porcine knee cartilage lesions show good healing with or without autologous chondrocyte transplantation

OBJECTIVE

The purpose of this study was to find out how deep chondral lesions heal in growing animals spontaneously and after autologous chondrocyte transplantation.

METHODS

A 6mm deep chondral lesion was created in the knee joints of 57 immature pigs and repaired with autologous chondrocyte transplantation covered with periosteum or muscle fascia, with periosteum only, or left untreated. After 3 and 12 months, the repair tissue was evaluated with International Cartilage Repair Society (ICRS) macroscopic grading, modified O'Driscoll histological scoring, and staining for collagen type II and hyaluronan, and with toluidine blue and safranin-O staining for glycosaminoglycans. The repair tissue structure was also examined with quantitative polarized light microscopy and indentation analysis of the cartilage stiffness.

RESULTS

The ICRS grading indicated nearly normal repair tissue in 65% (10/17) after the autologous chondrocyte transplantation and 86% (7/8) after no repair at 3 months. At 1 year, the repair tissue was nearly normal in all cases in the spontaneous repair group and in 38% (3/8) in the chondrocyte transplantation group. In most cases, the cartilage repair tissue stained intensely for glycosaminoglycans and collagen type II indicating repair tissue with true constituents of articular cartilage. There was a statistical difference in the total histological scores at 3 months (P=0.028) with the best repair in the spontaneous repair group. A marked subchondral bone reaction, staining with toluidine blue and collagen type II, was seen in 65% of all animals.

CONCLUSIONS

The spontaneous repair ability of full thickness cartilage defects of immature pigs is significant and periosteum or autologous chondrocytes do not bring any additional benefits to the repair.

Cyclosporine inhibits the development of green fluorescent protein (GFP)-specific immune responses after transplantation of GFP-expressing hematopoietic repopulating cells in dogs

Green fluorescent proteins (GFPs) have been widely used to monitor gene transfer and expression after lentiviral and oncoretroviral transduction of hematopoietic cells. Studies have shown a complete disappearance of GFP-containing cells after transplantation of GFP-transduced repopulating cells in nonhuman primates that was further shown to be mediated by transgene-specific immune responses. We wished to evaluate whether cyclosporine could prevent immune responses to GFP. We first determined whether an immune response to GFP was responsible for the disappearance of gene-modified cells in dogs. We performed immune assays in two dogs transplanted with lentivirally transduced CD34+ cells. Blood samples were obtained twice per week for up to 800 days and the GFP transgene product was measured by flow cytometry in blood leukocytes. Peripheral blood leukocytes were stimulated in vitro for 5 days, using a panel of GFP peptides. Intracellular levels of tumor necrosis factor alpha (TNF-alpha), measured by flow cytometry, and T cell proliferation after GFP peptide stimulation were measured. Dogs that exhibited a decrease in GFP marking developed potent immune responses in vitro to the transgene product GFP as shown by an increase in GFP-specific TNF-alpha production (p < 0.05) when compared with nontransplanted controls. T cells from dogs with low GFP marking exhibited a significant increase in proliferation in response to GFP peptide stimulation in vitro (p < 0.05). To study whether cyclosporine could inhibit the development of GFP-specific immune responses, we treated five dogs with cyclosporine after transplantation of GFP-transduced hematopoietic cells. Dogs treated with cyclosporine after hematopoietic stem cell transplantation showed stable GFP marking in blood leukocytes over 800 days. Our data suggest that cyclosporine prevents immunoactivation against transgene products after transplantation of GFP-transduced hematopoietic stem cells as indicated by stable GFP marking.

Clonal growth of human articular cartilage and the functional role of the periosteum in chondrogenesis

OBJECTIVE

Clinical cartilage repair with transplantation of cultured chondrocytes, the first described technique introduced in 1994, includes a periosteal membrane but today cells are also implanted without the periosteal combination. The aim of this study was to see if the periosteum had more than a biomechanical function and if the periosteum had a biological effect on the seeded cells tested in an agarose system in which the clonal growth in agarose and the external growth stimulation could be analysed.

METHODS

Four different experiments were used to study the growth of human chondrocytes in agarose and the periosteal influence. Human chondrocytes were isolated and transferred to either primary or secondary agarose culture. After 4 weeks, the total number of clones >50 microm was counted. Cocultures of chondrocytes and periosteal tissue, cultures of chondrocytes with conditioned medium from chondrocytes, periosteal cells and fibroblast were used to study a potential stimulatory effect on growth and different cytokines and growth factors were analysed.

RESULTS

It was found that the human chondrocytes had different growth properties in agarose with the formation of four different types of clones: a homogenous clone without matrix production, a homogenous clone with matrix production, a differentiated clone with matrix production and finally a differentiated clone without matrix production. The periosteum exerted a paracrine effect on cultured chondrocytes in agarose resulting in a higher degree of cloning. The chondrocytes produced significant amounts of interleukin (IL)-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor (TGF)-beta. The periosteum produced significant amounts of IL-6, IL-8 and TGF-beta. Cocultures of chondrocytes and periosteum demonstrated a potentiation of IL-6 and IL-8 release but not of TGF-beta and GM-CSF.

CONCLUSION

Articular chondrocytes are able to form clones of different properties in agarose and the periosteum has a capacity of stimulating chondrocyte clonal growth and differentiation and secretes significant amounts of IL-6, IL-8, GM-CSF and TGF-beta. It may be that the repair of cartilage defects with seeded chondrocytes could benefit from the combination with a periosteal graft. The production of TGF-beta by implanted chondrocytes could influence the chondrogenic cells in the periosteum to start a periosteal chondrogenesis and together with the matrix from implanted chondrocyte production, a repair of cartilaginous appearance may develop; a dual chondrogenic response is possible.

Subchondral bone reaction associated with chondral defect and attempted cartilage repair in goats

Repair of cartilage damage with autologous chondrocyte transplantation (ACT) has become popular in clinical use during the past few years. Although clinical results have mostly been successful, several unanswered questions remain regarding the biological mechanism of the repair process. The aim of this study was to develop a goat model for ACT. The repair was not successful due to the graft delamination, but we characterize the subchondral changes seen after the procedure. A chondral lesion was created in 14 goat knees, operated on 1 month later with ACT, and covered with periosteum or a bioabsorbable poly-L/D-lactide scaffold. After 3 months, only two of the five lesions repaired with ACT showed partly hyaline-like repair tissue, and all lesions (n = 4) with the scaffold failed. Even though the lesions did not extend through the calcified cartilage, the bone volume and collagen organization of bone structure were decreased when assessed by quantitative polarized light microscopy. There was a significant loss of bone matrix and distortion of the trabecular structure of subchondral bone, which extended several millimeters into the bone. The subchondral bone demonstrated strong hyaluronan staining in the bone marrow and cartilaginous areas with signs of endochondral ossification, suggesting structural remodeling of the bone. The goat model used here proved not to be an optimal model for ACT. The changes in subchondral bone may alter the biomechanical properties of the subchondral plate and thus the long-term survival of the repair tissue after ACT.

Health economics benefits following autologous chondrocyte transplantation for patients with focal chondral lesions of the knee

Autologous chondrocyte transplantation (ACT) for the treatment of cartilage injuries has been in clinical use for several years. Since this new technique is potentially more costly and invasive than traditional conservative therapies, we evaluated the effect of ACT on clinical outcome, absenteeism, disability status, and total direct economic burden in 57 patients with full-thickness chondral lesions of the knee treated between 1987 and 1996. Patients graded good or excellent following ACT in the treatments groups were: femoral condyles (28/33), femoral condyles with anterior cruciate ligament (ACL) repair (5/5), osteochondritis dissecans (7/8), and patellar lesions (9/11). Pre-ACT, 57/57 patients were disabled and post-ACT (mean follow-up 7.3 years) 44/57 had no sickness, 10/57 had minor disability, and 1/57 was disabled. Two of the 57 patients suffered re-injury during the follow-up time. In the 10-year period prior to ACT, the average cost of absenteeism and surgery was SEK 982,457 ($ 122,807) and SEK 47,000 ($ 5,875), respectively, compared to the post-ACT period where both absenteeism and medical costs were dramatically reduced: SEK 9,508 ($ 1,189) and SEK 7,050 ($ 881), respectively. In conclusion, 49 of the 57 patients improved clinically as a result of the ACT treatment. A dramatic cost-saving effect was demonstrated over a projected 10-year period due to reduced absenteeism and disability.

Sustained multilineage gene persistence and expression in dogs transplanted with CD34(+) marrow cells transduced by RD114-pseudotype oncoretrovirus vectors

Previous studies have shown that the choice of envelope protein (pseudotype) can have a significant effect on the efficiency of retroviral gene transfer into hematopoietic stem cells. This study used a competitive repopulation assay in the dog model to evaluate oncoretroviral vectors carrying the envelope protein of the endogenous feline virus, RD114. CD34-enriched marrow cells were divided into equal aliquots and transduced with vectors produced by the RD114-pseudotype packaging cells FLYRD (LgGLSN and LNX) or by the gibbon ape leukemia virus (GALV)-pseudotype packaging cells PG13 (LNY). A total of 5 dogs were studied. One dog died because of infection before sustained engraftment could be achieved, and monitoring was discontinued after 9 months in another animal that had very low overall gene-marking levels. The 3 remaining animals are alive with follow-ups at 11, 22, and 23 months. Analyses of gene marking frequencies in peripheral blood and marrow by polymerase chain reaction revealed no significant differences between the RD114 and GALV-pseudotype vectors. The LgGLSN vector also contained the enhanced green fluorescent protein (GFP), enabling us to monitor proviral expression by flow cytometry. Up to 10% of peripheral blood cells expressed GFP shortly after transplantation and approximately 6% after the longest follow-up of 23 months. Flow cytometric analysis of hematopoietic subpopulations showed that most of the GFP-expressing cells were granulocytes, although GFP-positive lymphocytes and monocytes were also detected. In summary, these results show that RD114-pseudotype oncoretroviral vectors are able to transduce hematopoietic long-term repopulating cells and, thus, may be useful for human stem cell gene therapy.

Autologous chondrocytes used for articular cartilage repair: an update

Articular cartilage in adults has a poor ability to self-repair after a substantial injury; however, it is not known whether there is a cartilage resurfacing technique superior to the existing techniques. It is not satisfactory that at the beginning of the new millennium, there still is a lack of randomized studies comparing different cartilage repair techniques and there still is little knowledge of the natural course of a cartilaginous lesion. To date, various articular cartilage resurfacing techniques have the potential to improve the repair of cartilage defects and reduce the patient's disability. One such cartilage repair technique is autologous chondrocyte transplantation combined with a periosteal graft. Since the first patient was operated on in 1987, much interest in cartilage repair and cell engineering has emerged. The experience with autologous chondrocyte transplantation during the past 13 years with in vitro chondrocyte expansion, cartilage harvest, and postoperative biopsy technique is discussed, and the latest followup of 213 consecutive patients in different subgroups with 2 to 10 years followup is presented. The technique gives stable long-term results with a high percentage of good to excellent results (84%-90%) in patients with different types of single femoral condyle lesions, whereas patients with other types of lesions have a lower degree of success (mean, 74%).

Maternal use of baby walkers with young children: recent trends and possible alternatives

OBJECTIVES

To examine recent trends in baby walker and exersaucer use, and to assess maternal motivations for choosing to use or not use these devices with children.

SETTING

Small, Midwestern city in the United States.

METHODS

Retrospective telephone survey with a sample of 329 mothers who provided information about their use of walkers and exersaucers with 463 children born in Columbia, Missouri between January 1994 and April 1999.

RESULTS

Baby walker use in the sample declined fairly steadily from 1994 to 1999, whereas exersaucer use increased during the same period. Altogether 88% of mothers were aware of the injury risks associated with walkers, and this knowledge was the most commonly reported reason for abstaining from walker use. Remarkably, 38% of participants with knowledge of walker risks nevertheless used these devices. Participants reported many reasons for using walkers and exersaucers, including child entertainment, perceived developmental benefit, easy availability, and improved safety of exersaucers.

CONCLUSIONS

Public knowledge of the hazards of walkers seems to be high, and this awareness is a likely factor in many caregivers' decisions not to use them. Future interventions should focus particular attention on those caregivers who continue to use walkers despite knowledge of the associated risks. In addition to persuasive interventions, alternatives to walkers should be encouraged. Exersaucers represent one viable alternative, and should be promoted as such by the media, pediatricians, and other child care professionals.