Carboplatin dose calculations for patients with lung cancer: significant dose differences found depending on dosing equation choice.

BACKGROUND: Carboplatin is the backbone cytotoxic agent for many chemotherapy regimens for lung cancer. Dosing of carboplatin is complicated due to its relationship to renal function and narrow therapeutic index. Overestimation of renal function may lead to supratherapeutic dosing and toxicity, while underestimation may lead to underdosing and therapeutic failure. Although the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations have higher accuracy in estimating glomerular filtration rate (eGFR), the Cockcroft Gault (CG) formula has been historically used for carboplatin dosing internationally. METHODS: We compared these formulae to identify patient profiles that were associated with significant carboplatin dose variation by retrospectively analysing the carboplatin dosing of 96 patients with lung cancer. Carboplatin doses were calculated using eGFR generated by MDRD, CKD-EPI 2009 and CKD-EPI 2021 equations. These three hypothetical doses were compared to actual CG-based doses prescribed. RESULTS: MDRD and CKD-EPI equations resulted in comparable carboplatin doses; however, CG doses diverged markedly with up to 17% of the patients receiving a carboplatin dose that was at least 20% higher than a non-CG formula would have predicted, and 20% received a dose that was at least 20% lower than a non-CG formula would have predicted. Our data suggest CG use overestimates kidney function in patients with a higher bodyweight and body surface area (BSA) while underestimating it in patients with a lower bodyweight and BSA. Importantly, we demonstrate potential real-world benefit as CKD-EPI predicted lower doses for patients whose (CG-derived) carboplatin dose was later reduced following clinical assessment prior to infusion. CONCLUSIONS: We have therefore confirmed significant differences in carboplatin dosing depending on the equation used in our modern patient population and suggest that use of CKD-EPI provides the most clinically appropriate carboplatin dosing and should be implemented as the new standard of care internationally.

Referral rates to multidisciplinary team meetings: Is there disparity between tumour streams?

INTRODUCTION: The multidisciplinary team meeting (MDTM) approach is accepted as standard of care to optimise treatment for patients diagnosed with cancer. This retrospective audit reviews the proportion of patients whose care is being discussed at cancer MDTMs within the Sunshine Coast Hospital and Health Service (SCHHS). METHODS: Patients included were those diagnosed with cancer within the SCHHS between 2010 and 2015, and subsequently referred to a public MDTM for discussion. Data were extracted from the Queensland Cancer Control Analysis Team (QCCAT) database regarding the incidence of breast, lung, upper gastrointestinal (GI), colorectal, genitourinary and malignant haematological cancers and the number of patients referred to the corresponding MDTM. RESULTS: Data from 2015 show referral rates to MDTMs as follows: lung 100%, upper gastrointestinal 100%, colorectal 64%, breast 60%, malignant haematology 40% and genitourinary 28%. Of the genitourinary presentations, 70% were prostate cases and 14% bladder cases. Review of genitourinary MDTM outcomes found that, of the patients with prostate cancer discussed, 30% were metastatic, 19% were poor surgical candidates and 15% had biochemical recurrence. CONCLUSION: This audit demonstrates variable utilisation of MDTMs between tumour streams. Our study shows a high and increasing referral rate to all tumour stream MDTMs except for genitourinary. This suggests a possible underutilisation of genitourinary MDTMs to discuss treatment options for patients with genitourinary cancer. Collaborative research is warranted to further investigate whether this is a local or widespread issue.

Effects of astrocyte-targeted production of interleukin-6 in the mouse on the host response to nerve injury.

Interleukin-6 (IL-6) is a pleiotropic cytokine with a key role in the control of inflammatory/immune responses. In the central nervous system (CNS), an increase in IL-6 occurs in a wide range of pathological conditions such as excitotoxicity and traumatic brain injury. We evaluated the effects of astrocyte-targeted production of IL-6 in the CNS in the sterile-nerve injury model of facial nerve axotomy. To accomplish this, facial nerve transection was performed in transgenic mice (glial fibrillary acidic protein [GFAP]-IL6Tg) with IL-6 production under the GFAP promoter. Neuronal death, glial activation, lymphocyte recruitment, and integrin expression were evaluated by immunohistochemistry and flow cytometry from 3 to 28 days postinjury. Our findings revealed an increase in motor neuron cell death in GFAP-IL6Tg mice correlating with changes in the microglial activation pattern, characterized principally by less attachment to neurons and reduced expression of both CD11b and CD18. We also found a higher CD4(+) T-lymphocyte recruitment in GFAP-IL6Tg mice. In addition, changes in the expression pattern of different integrins and their receptors were observed in transgenic animals. Specifically, alterations in osteopontin expression in motor neurons and its receptors CD44 and CD49e in lymphocytes and microglia, respectively, which may account for the variations related to glial reactivity and lymphocyte infiltration. In conclusion, our results indicated that forced local production of IL-6 has a direct impact on the outcome of nerve injury in the CNS inducing an increase in neurodegeneration, changes in glial response, and lymphocyte recruitment as well as in the expression of different integrins and their receptors.

Interferon regulatory factor 7 (IRF7) is required for the optimal initial control but not subsequent clearance of lymphocytic choriomeningitis virus infection in mice.

The role of IRF7 in the host response to lymphocytic choriomeningitis virus (LCMV) Armstrong 53b infection of mice was investigated. Intracranial infection of IRF7 KO mice was associated with delayed onset of LCM, increased survival and significantly reduced expression of the Ifng gene in the brain but not in the periphery. IRF7 KO mice showed impaired control of LCMV replication and delayed clearance of LCMV. Similar numbers of activated anti-LCMV-GP(33-41) CD8+ T cells were present in the brain and spleens of infected WT and IRF7 KO mice. While plasma IFN-ß was increased to similar levels, IFN-α was markedly reduced in IRF7 KO compared with WT mice. Compared with IFN-ß, IFN-α was a less potent inhibitor of LCMV infection in vitro. In conclusion, IRF7 (1) is required for the early innate control of LCMV infection, likely through the regulation of the appropriate type I IFN response, and (2) is not required for the antiviral CD8+ T cell-dependent clearance of LCMV from infected tissues.

Mice deficient in STAT1 but not STAT2 or IRF9 develop a lethal CD4+ T-cell-mediated disease following infection with lymphocytic choriomeningitis virus.

Interferon (IFN) signaling is crucial for antiviral immunity. While type I IFN signaling is mediated by STAT1, STAT2, and IRF9, type II IFN signaling requires only STAT1. Here, we studied the roles of these signaling factors in the host response to systemic infection with lymphocytic choriomeningitis virus (LCMV). In wild-type (WT) mice and mice lacking either STAT2 or IRF9, LCMV infection was nonlethal, and the virus either was cleared (WT) or established persistence (STAT2 knockout [KO] and IRF9 KO). However, in the case of STAT1 KO mice, LCMV infection was lethal and accompanied by severe multiorgan immune pathology, elevated expression of various cytokine genes in tissues, and cytokines in the serum. This lethal phenotype was unaltered by the coabsence of the gamma interferon (IFN-γ) receptor and hence was not dependent on IFN-γ. Equally, the disease was not due to a combined defect in type I and type II IFN signaling, as IRF9 KO mice lacking the IFN-γ receptor survived infection with LCMV. Clearance of LCMV is mediated normally by CD8(+) T cells. However, the depletion of these cells in LCMV-infected STAT1 KO mice was delayed, but did not prevent, lethality. In contrast, depletion of CD4(+) T cells prevented lethality in LCMV-infected STAT1 KO mice and was associated with a reduction in tissue immune pathology. These studies highlight a fundamental difference in the role of STAT1 versus STAT2 and IRF9. While all three factors are required to limit viral replication and spread, only STAT1 has the unique function of preventing the emergence of a lethal antiviral CD4(+) T-cell response.

The cell-specific induction of CXC chemokine ligand 9 mediated by IFN-gamma in microglia of the central nervous system is determined by the myeloid transcription factor PU.1.

The IFN-gamma-inducible chemokines CXCL9 and CXCL10 are implicated in the pathogenesis of T cell-mediated immunity in the CNS. However, in various CNS immune pathologies the cellular localization of these chemokines differs, with CXCL9 produced by macrophage/microglia whereas CXCL10 is produced by both macrophage/microglia and astrocytes. In this study, we determined the mechanism for the microglial cell-restricted expression of the Cxcl9 gene induced by IFN-gamma. In cultured glial cells, the induction of the CXCL9 (in microglia) and CXCL10 (in microglia and astrocytes) mRNAs by IFN-gamma was not inhibited by cycloheximide. Of various transcription factors involved with IFN-gamma-mediated gene regulation, PU.1 was identified as a constitutively expressed NF in microglia but not in astrocytes. STAT1 and PU.1 bound constitutively to the Cxcl9 gene promoter in microglia, and this increased significantly following IFN-gamma treatment with IFN regulatory factor-8 identified as an additional late binding factor. However, in astrocytes, STAT1 alone bound to the Cxcl9 gene promoter. STAT1 was critical for IFN-gamma induction of both the Cxcl9 and Cxcl10 genes in microglia and in microglia and astrocytes, respectively. The small interfering RNA-mediated knockdown of PU.1 in microglia markedly impaired IFN-gamma-induced CXCL9 but not STAT1 or IFN regulatory factor-8. Cells of the D1A astrocyte line showed partial reprogramming to a myeloid-like phenotype posttransduction with PU.1 and, in addition to the expression of CD11b, acquired the ability to produce CXCL9 in response to IFN-gamma. Thus, PU.1 not only is crucial for the induction of CXCL9 by IFN-gamma in microglia but also is a key determinant factor for the cell-specific expression of this chemokine by these myeloid cells.

Chemokine gene expression during fatal murine cerebral malaria and protection due to CXCR3 deficiency.

Cerebral malaria (CM) can be a fatal manifestation of Plasmodium falciparum infection. Using murine models of malaria, we found much greater up-regulation of a number of chemokine mRNAs, including those for CXCR3 and its ligands, in the brain during fatal murine CM (FMCM) than in a model of non-CM. Expression of CXCL9 and CXCL10 RNA was localized predominantly to the cerebral microvessels and in adjacent glial cells, while expression of CCL5 was restricted mainly to infiltrating lymphocytes. The majority of mice deficient in CXCR3 were found to be protected from FMCM, and this protection was associated with a reduction in the number of CD8+ T cells in brain vessels as well as reduced expression of perforin and FasL mRNA. Adoptive transfer of CD8+ cells from C57BL/6 mice with FMCM abrogated this protection in CXCR3-/- mice. Moreover, there were decreased mRNA levels for the proinflammatory cytokines IFN-gamma and lymphotoxin-alpha in the brains of mice protected from FMCM. These data suggest a role for CXCR3 in the pathogenesis of FMCM through the recruitment and activation of pathogenic CD8+ T cells.

Induction of the genes for Cxcl9 and Cxcl10 is dependent on IFN-gamma but shows differential cellular expression in experimental autoimmune encephalomyelitis and by astrocytes and microglia in vitro.

The chemokines CXCL9 and CXCL10 bind to the common receptor CXCR3 and are implicated in the pathogenesis of T-cell-mediated immunity in the central nervous system (CNS). Here we examined the temporal and spatial regulation of the Cxcl9 and Cxcl10 genes in the CNS of mice with myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) and by glial cells in vitro. During peak disease the levels of CXCL9 and CXCL10 mRNA and protein were increased significantly in the cerebellum and spinal cord but were reduced during the recovery phase. Expression of these genes in the CNS was abolished in IFN-gamma-receptor deficient mice with MOG-EAE. In wild-type mice, CXCL9 RNA was localized mainly to infiltrating mononuclear cells including lesion and perilesional microglia, while CXCL10 RNA was seen primarily in more distal astrocytes that surrounded the inflammatory lesions. Examination of cultured glia following treatment with IFN-gamma revealed that while both CXCL9 and CXCL10 mRNA transcripts were induced in microglia, only CXCL10 mRNA was induced in astrocytes. Thus, although IFN-gamma is the pivotal mediator of both Cxcl10 and Cxcl9 gene expression in EAE, this cytokine differentially regulates the expression of these genes by astrocytes and microglia. The differential glial localization of these chemokines in EAE suggests CXCL9 and CXCL10 have specialized functions.

CXCR3 signaling reduces the severity of experimental autoimmune encephalomyelitis by controlling the parenchymal distribution of effector and regulatory T cells in the central nervous system.

The chemokine receptor CXCR3 promotes the trafficking of activated T and NK cells in response to three ligands, CXCL9, CXCL10, and CXCL11. Although these chemokines are produced in the CNS in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE), their role in the pathogenesis of CNS autoimmunity is unresolved. We examined the function of CXCR3 signaling in EAE using mice that were deficient for CXCR3 (CXCR3(-/-)). The time to onset and peak disease severity were similar for CXCR3(-/-) and wild-type (WT) animals; however, CXCR3(-/-) mice had more severe chronic disease with increased demyelination and axonal damage. The inflammatory lesions in WT mice consisted of well-demarcated perivascular mononuclear cell infiltrates, mainly in the spinal cord and cerebellum. In CXCR3(-/-) mice, these lesions were more widespread throughout the CNS and were diffused and poorly organized, with T cells and highly activated microglia/macrophages scattered throughout the white matter. Although the number of CD4(+) and CD8(+) T cells infiltrating the CNS were similar in CXCR3(-/-) and WT mice, Foxp3(+) regulatory T cells were significantly reduced in number and dispersed in CXCR3(-/-) mice. The expression of various chemokine and cytokine genes in the CNS was similar in CXCR3(-/-) and WT mice. The genes for the CXCR3 ligands were expressed predominantly in and/or immediately surrounding the mononuclear cell infiltrates. We conclude that in EAE, CXCR3 signaling constrains T cells to the perivascular space in the CNS and augments regulatory T cell recruitment and effector T cell interaction, thus limiting autoimmune-mediated tissue damage.

A meta-analysis of clinical studies to estimate the 4.5-year survival rate of implants placed with the osteotome technique.

PURPOSE: To estimate the survival rate of implants placed with the osteotome technique by means of a systematic review. MATERIALS AND METHODS: The literature was searched using Medline; the search was limited to the years 1953 to 2005. Inclusion criteria were: (1) clinical studies or clinical reports investigating the osteotome technique for dental implantation and (2) control or test group(s) from clinical studies or clinical reports, even if they did not fit with other criteria. By pooling the data of the included studies, overall Kaplan-Meier survival curves were constructed for the periods before and after loading. RESULTS: The initial literature search yielded 164 studies. After selection criteria were applied, 5 studies were considered suitable for inclusion. The combined data of 349 implants revealed survival probabilities of 98% (confidence interval [CI], 97.2% to 100%) until loading and 99% (CI, 94% to 100%) after 56 months of loading. At the end of the observation period 41 implants in 18 patients were still at risk. CONCLUSION: The outcome of dental implantation using the osteotome technique in terms of implant survival seems to be similar to that of implants placed by means of the conventional implantation technique.

Bone response adjacent to calcium phosphate electrostatic spray deposition coated implants: an experimental study in goats.

BACKGROUND: A new technique to deposit calcium phosphate (CaP) coatings onto titanium substrates has been developed recently. This electrostatic spray deposition (ESD) technique seems to be very promising. It appears to have clinical advantages such as an inexpensive and simple set-up, high deposition efficiency and the possibility to synthesize layers with a defined surface morphology. OBJECTIVE: The aim of this study was to examine biological properties and osteoconductivity of ESD CaP coatings when inserted into the femoral condyle of a goat. MATERIAL AND METHODS: Twenty-four implants with two gaps, i.e. 1 or 2 mm, were inserted into the femoral condyles of six goats. The implants were coated on one side with either a commercially available plasma-sprayed hydroxyapatite (HAPS) coating or an ESD carbonate apatite (CAESD) coating. The other side of the implant was always left uncoated (Ti). Twelve weeks after implantation the animals were sacrificed and the characteristics of bone ingrowth and bone contact were evaluated. RESULTS: At 3 months, histological and quantitative histomorphometrical measurements demonstrated more bone ingrowth and bone contact for coated sites as compared with uncoated sites. Statistical testing revealed that for both the 1 and 2 mm gaps HAPS (plasma-sprayed hydroxyapatite) as well as CAESD (ESD carbonate apatite) -coated surfaces always had a significantly higher (P<0.05) amount of bone contact than uncoated Ti surfaces. On HAPS surfaces always significantly more bone was present than on CAESD surfaces. Further statistical testing revealed a significant difference in bone ingrowth between the HAPS as well as CAESD and Ti 1+2 mm gap specimens (P<0.05). Further, HAPS 1 mm gaps showed more bone ingrowth than CAESD 1 mm gaps. No significant difference existed between HAPS and CAESD 2 mm gaps. CONCLUSION: On the basis of our observations, we conclude that the used ESD technique is a promising new method to deposit CaP coatings onto titanium substrates. On the other hand, plasma-spray HA-coated implants have a still more favourable effect on the bone response.

BCL6b mediates the enhanced magnitude of the secondary response of memory CD8+ T lymphocytes.

A characteristic of the secondary response of CD8(+) T cells that distinguishes it from the primary response is the generation of greater numbers of effector cells. Because effector CD8(+) T cells are derived from a pool of less differentiated, replicating cells in secondary lymphoid organs, and because IL-2 mediates effector differentiation, the enhanced secondary response may reflect the enlargement of this generative pool by the transient repression of IL-2-mediated differentiation. We have examined for this function the transcriptional repressor BCL6b, a homologue of BCL6 that represses IL-2-induced B cell differentiation. BCL6b is expressed in a small subset of antigen-experienced CD8(+) T cells. Ectopic expression of BCL6b in CD8(+) T cells diminishes their growth in response to IL-2 in vitro. Female mice in which the BCL6b gene has been interrupted have normal primary responses of CD8(+) T cells to infection with vaccinia expressing the H-Y epitope, Uty, but Uty-specific, BCL6b(-/-), memory CD8(+) T cells have diminished recall proliferative responses to this epitope in vitro. BCL6b(-/-) mice also have normal primary CD8(+) T cell responses to influenza infection, but nucleoprotein peptide-specific, BCL6b(-/-), memory CD8(+) T cells have a cell autonomous defect in the number of effector cells generated in response to reinfection. Therefore, BCL6b is required for the enhanced magnitude of the secondary response of memory CD8(+) T cells.