Association of CYP2D6 genotype predicted phenotypes with oxycodone requirements and side effects in children undergoing surgery.

Background: Oxycodone is a commonly used oral opioid in children for treating postoperative pain. Highly polymorphic gene CYP2D6 metabolizes oxycodone into its more potent metabolite, oxymorphone. We hypothesized that altered activity due to CYP2D6 polymorphisms will influence oxycodone requirements {relative oxycodone use [oxycodone morphine equivalents (MEq)/total MEq] to maintain analgesia} (primary outcome) and risk for oxycodone induced side-effects such as respiratory depression (RD) and emesis (secondary outcomes). We also explored the influence of genotype availability and provider guidance on oral opioid prescription patterns. Methods: Patients who underwent Nuss procedure and spine fusion with CYP2D6 genotyping results available preoperatively were included. Data on demographics, genotypes, oral opioids, pain scores, RD and emesis were collected. Univariate and multivariable regression for comparison of CYP2D6 genotype predicted poor, ultrarapid, intermediate metabolizers (PM, UM and IM) phenotype with normal metabolizers (NM) for outcomes were performed. Stratified logistic regression was conducted in low (oxycodone/total MEq <0.5) and high (and oxycodone/total MEq >0.5) oxycodone use groups for RD and emesis, with application of firth correction due to quasi-complete separations. Breslow-Day test was used to evaluate odds ratios for prescribing genotype directed opioid between control group (2012-15) (where providers were alerted to genotyping results availability but not directed to use them while prescribing) and genotype directed groups (2016-18) (where providers were directed to use the genotyping results available to them while prescribing oxycodone after surgery). Results: Of 193 subjects (age 15.9±0.25 years, 28.5% female, 93.78% White; 101 NM, 76 IM, 10 PM and 6 UM), 77.72% underwent pectus surgery. CYP2D6 phenotype was associated with oxycodone MEq/total MEq requirements (P<0.001). Both PM and UM phenotypes had lower oxycodone requirements compared to NM [-0.316 (SE 0.098), P=0.005 and -0.432 (SE 0.113), P<0.001 respectively]. CYP2D6 phenotype was associated with RD in high use oxycodone group (P=0.018) but not low use oxycodone groups (P=0.634). No phenotype association was found for emesis. Oxycodone was prescribed to 91.24% of NM/IM vs. 66.67% of PM/UM (P=0.129) in control group and 94.64% of NM/IM vs. 28.57% of PM/UM (P<0.001) in the genotype-directed group. PM/UM phenotypes in genotype directed group had a lower chance of being prescribed oxycodone (effect size =-2.775; SE 1.566; P=0.076). Conclusions: Our findings suggest CYP2D6 genotypes are associated with oxycodone requirements for analgesia and may influence risk for RD. Genotype availability and guidance likely influence oral opioid prescription pattern after surgery. Our findings are limited by small sample size for UM/PM groups.

Postoperative Pain Management in Pediatric Spinal Fusion Surgery for Idiopathic Scoliosis.

This article reviews and summarizes current evidence and knowledge gaps regarding postoperative analgesia after pediatric posterior spine fusion for adolescent idiopathic scoliosis, a common procedure that results in severe acute postoperative pain. Inadequate analgesia may delay recovery, cause patient dissatisfaction, and increase chronic pain risk. Despite significant adverse effects, opioids are the analgesic mainstay after scoliosis surgery. However, growing emphasis on opioid minimization and enhanced recovery has increased adoption of multimodal analgesia (MMA) regimens. While opioid adverse effects remain a concern, MMA protocols must also consider risks and benefits of adjunct medications. We discuss use of opioids via different administration routes and elaborate on the effect of MMA components on opioid/pain and recovery outcomes including upcoming regional analgesia. We also discuss risk for prolonged opioid use after surgery and chronic post-surgical pain risk in this population. Evidence supports use of neuraxial opioids at safe doses, low-dose ketorolac, and methadone for postoperative analgesia. There may be a role for low-dose ketamine in those who are opioid-tolerant or have chronic pain, but the evidence for preoperative gabapentinoids and intravenous lidocaine is currently insufficient. There is a need for further studies to evaluate pediatric-specific optimal MMA dosing regimens after scoliosis surgery. Questions remain regarding how best to prevent acute opioid tolerance, opioid-induced hyperalgesia, and chronic postsurgical pain. We anticipate that this timely update will enable clinicians to develop efficient pain regimens and provide impetus for future research to optimize recovery outcomes after spine fusion.

Upregulation of genes for C-reactive protein and related pentraxin/complement proteins in photodynamic therapy-treated human tumor cells: enrolment of PI3K/Akt and AP-1.

Treatment of mouse tumors by photodynamic therapy (PDT) was reported to trigger the production of serum amyloid P component (SAP), a prototypic acute phase reactant in the mouse, that occurs in the targeted tumor as well as distant sites dominated by host's liver. It was also shown that the SAP gene becomes upregulated and protein produced in mouse tumor cells treated by PDT in vitro. Present study revealed that, in addition to SAP, increased expression of genes encoding related pentraxin and complement proteins, including PTX3, C1q and ficolin B, can be found in mouse LLC tumor cells treated by PDT. Since in humans C-reactive protein (CRP) is more important acute phase reactant than SAP, the expression of gene encoding this pentraxin protein was examined in human lung tumor A549 cells treated by PDT. The results demonstrated a PDT dose-dependent upregulation of CRP gene, as well as of PTX3 and ficolin 1 genes in these cells. Investigation into the signal transduction process underlying PDT-induced human CRP gene upregulation using specific inhibitors of critical signaling elements revealed critical role played by PI3K/Akt pathway. Downstream DNA transcription factor largely responsible for this increased CRP gene expression is AP-1 with possible cooperation of HIF-1. It was suggested that cells sensing to have sustained a mortal injury from PDT can turn on molecular programs ensuring that the disposal of their corpses (facilitated by CRP and related pentraxin and complement components) is swift and efficient.

Photodynamic therapy-generated cancer vaccine elicits acute phase and hormonal response in treated mice.

Photodynamic therapy (PDT)-generated cancer vaccines have shown promising results in preclinical studies and are being introduced in the clinics. Using an SCCVII mouse squamous cell carcinoma-based whole-cell autologous PDT vaccine model developed in our previous work, we have examined systemic effects in vaccinated mice that could be related to the induction of acute phase response. The upregulation of gene encoding serum amyloid P component (prototypic mouse acute phase reactant) was detected in the liver and to a lesser degree in the tumor of vaccinated mice at 24 h post-PDT vaccine treatment. A strong upregulation of gene for heat shock protein 70 was found in both the liver and tumor of mice at 4 h after their PDT vaccine treatment. Changes in the expression of genes for glucocorticoid-induced leucine zipper and serum- and glucocorticoid-regulated kinase 1 that are highly responsive to glucocorticoid modulation were uncovered in both the tumor and liver of vaccinated mice. A rise in the levels of serum corticosterone was detected in mice at 24 h after PDT vaccine treatment. The results indicate that a sudden appearance of a large number of PDT vaccine cells elicits host responses for securing their optimized clearance, which in addition to producing seminal acute phase reactants includes the engagement of glucocorticoid hormones. It is becoming increasingly clear that a consummate execution of this process of PDT vaccine cell removal is critical for tumor antigen recognition and the attainment of potent antitumor immune response.

Involvement of damage-associated molecular patterns in tumor response to photodynamic therapy: surface expression of calreticulin and high-mobility group box-1 release.

Damage-associated molecular patterns (DAMPs), danger signal molecules expressed after injury or infection, have become recognized as prerequisite for orchestrating effective anti-tumor host response. The expression of two prototypical DAMPs, calreticulin and high-mobility group box-1 (HMGB1) protein, was examined following Photofrin-photodynamic therapy (PDT) of Lewis lung carcinoma (LLC) cells in vitro and LLC tumors growing in syngeneic mice. Cell surface expression of calreticulin was found to be highly increased at 1 h after PDT treatment both in vitro and in vivo. Increased exposure of calreticulin was also detected on the surface of macrophages from PDT-treated LLC tumors. At the same time interval, a rise in serum HMGB1 was detected in host mice. Intracellular staining of macrophages co-incubated for 16 h with PDT-treated LLC cells revealed elevated levels of HMGB1 in these cells. The knowledge of the involvement of these DAMPs uncovers important mechanistic insights into the development of host response induced by PDT.

Heat shock protein 70 is acute phase reactant: response elicited by tumor treatment with photodynamic therapy.

Oxidative stress in photodynamic therapy (PDT)-treated tumor cells is known to instigate a strong upregulation of the expression of heat shock proteins. However, the treatment of mouse Lewis lung carcinoma (LLC) cells with Photofrin™ PDT resulted in the upregulation of heat shock protein 70 (Hsp70) gene not only in these cells but also in co-incubated untreated Hepa 1-6 cells. To investigate whether this phenomenon extends in vivo, LLC tumors growing in C57BL/6 mice were treated with Photofrin™ PDT. The tumors and the livers from the mice were collected at 4, 8, or 24 h after therapy for quantitative reverse transcriptase polymerase chain reaction-based analysis of Hsp70 gene expression. Increased Hsp70 gene expression was detected in both the tumor and liver tissues and was most pronounced at 4 h after PDT. This effect was inhibited by treatment of host mice with glucocorticoid synthesis inhibitor metyrapone. Hsp70 protein levels in the livers of mice bearing PDT-treated tumors gradually decreased after therapy while serum levels increased at 4 h after therapy and then continually decreased. The exposure of in vitro PDT-treated LLC cells to Hsp70 and subsequent flow cytometry analysis revealed binding of this protein to cells that was dependent on PDT dose and more pronounced with dying than viable cells. Thus, following the induction of tumor injury by PDT, Hsp70 can be produced in the liver and spleen as acute phase reactant and released into circulation, from where it can be rapidly sequestered to damaged tumor tissue to facilitate the disposal of dying cells.

Expression of complement and pentraxin proteins in acute phase response elicited by tumor photodynamic therapy: the engagement of adrenal hormones.

Treatment of solid tumors by photodynamic therapy (PDT) was recently shown to trigger a strong acute phase response. Using the mouse Lewis lung carcinoma (LLC) model, the present study examined complement and pentraxin proteins as PDT-induced acute phase reactants. The results show a distinct pattern of changes in the expression of genes encoding these proteins in the tumor, as well as host liver and spleen, following PDT mediated by photosensitizer Photofrin™. These changes were influenced by glucocorticoid hormones, as evidenced by transcriptional activation of glucocorticoid receptor and the upregulation of gene encoding this receptor. The expression of gene for glucocorticoid-induced zipper (GILZ) protein, whose activity is particularly susceptible to glucocorticoid regulation, was also changed in PDT-treated tumors. A direct demonstration that tumor PDT induces glucocorticoid hormone upregulation is provided by documenting elevated levels of serum corticosterone in mice bearing PDT-treated LLC tumors. Tumor response to PDT was negatively affected by blocking glucocorticoid receptor activity, which suggests that glucocorticoid hormones have a positive impact on the therapeutic outcome with this therapy.

Exploitation of immune response-eliciting properties of hypocrellin photosensitizer SL052-based photodynamic therapy for eradication of malignant tumors.

A diaminophenyl derivative of hypocrellin B (SL052) has been developed as a photosensitizer for use in photodynamic therapy (PDT) of solid tumors. Testing SL052-PDT on mouse carcinoma and fibrosarcoma models revealed a typical response seen with clinically established photosensitizers featuring initial rapid tumor ablation with ensuing recurrence at rates dependent on photosensitizer/light doses. Elevated numbers of immune cells were found in lymph nodes draining SCCVII mouse squamous cell carcinomas treated by SL052-PDT (in particular T cells), and the accumulation of degranulating cytotoxic T cells was detected at the tumor-treated site. This indicates that a significant contribution to tumor cures is elicited by an antitumor adaptive immune response. Two different immunotherapy agents, gamma-interferon and antibody blocking inhibitory FcgammaRIIB receptor, were both found to be highly effective in potentiating the curative effect of SL052-PDT with SCCVII tumors. Combining SL052-PDT with FcgammaRIIB-blocking antibody treatment caused a further increase in the number of cells in tumor-draining lymph nodes and in degranulating CD8+ cells, suggesting the amplification of the immune response induced by PDT. Vaccines consisting of SCCVII cells treated with SL052-PDT in vitro were effective in reducing growth of established subcutaneous SCCVII tumors. In conclusion, PDT mediated by SL052 is suitable to be integrated with various immunotherapy protocols.

Acute phase response induction by cancer treatment with photodynamic therapy.

Inflammation and immunity development are well recognized as responses to tumor treatment by photodynamic therapy (PDT). To demonstrate that another major host response effector process, acute phase response, may be also induced by this cancer treatment modality, the expression of serum amyloid P component (SAP) acknowledged as a hallmark acute phase reactant in the mouse was investigated following PDT of murine FsaR fibrosarcomas. The results reveal almost 150-fold increase in the expression of SAP gene in the liver of mice bearing tumors treated by Photofrin-mediated PDT, while serum SAP levels increased around 50-fold at the peak interval about 24 hr post PDT. The same tumor treatment induced also the liver gene upregulation and serum levels elevation of another established acute phase reactant, mannose-binding lectin A (MBL-A). Both SAP and MBL-A were found to accumulate in PDT-treated tumors, but this includes local production because their genes in these tumor tissues were upregulated as well. Gene encoding C-reactive protein (CRP) was also upregulated almost 7-fold in the same tumor tissues, suggesting a rare example of CRP participation in host response of the mouse. Interleukin-6 and glucocorticoid hormones were identified as major mediators promoting tumor PDT-induced upregulation of liver SAP gene. Moreover, glucocorticoids were found to act as critical inducers of SAP gene upregulation in PDT-treated tumors. The study definitely proves the occurrence of a strong acute phase response following tumor PDT, and reveals that glucocorticoid hormones released during this development impact the expression of host response-relevant genes in PDT-treated tumors.

Dying cells program their expedient disposal: serum amyloid P component upregulation in vivo and in vitro induced by photodynamic therapy of cancer.

Serum amyloid P component (SAP) is known as a prototypic acute phase reactant in the mouse and the protein that binds to dying cells securing their swift disposal by phagocytes. Treatment of solid tumors by photodynamic therapy (PDT) triggers SAP production in the liver of host mice, its release in the circulation and accumulation in PDT-targeted lesions. In the present study, mouse Lewis lung carcinoma (LLC) cells treated in vitro by PDT are shown to upregulate their gene encoding SAP. This effect was manifested following PDT treatment mediated by various types of photosensitizers (Photofrin, BPD, mTHPC, ALA). Generated SAP protein was not detected in tissue supernatants but remained localized to producing PDT-treated cells. The upregulation of SAP gene was observed also in untreated IC-21 macrophages after they were co-incubated for 4 h with PDT-treated LLC cells. Based on these findings, SAP that accumulates in PDT-treated tumors may originate from both systemic sources (released from the liver as acute phase reactant) and local sources; the latter could include tumor cells directly sustaining PDT injury and macrophages invading the tumor that become stimulated by signals from these affected tumor cells. Since SAP gene upregulation in LLC cells increased with the lethality of PDT dose used for their treatment, we propose that cells sensing they are inflicted with mortal injury can turn on molecular programs insuring not only that they die an innocuous form of death (apoptosis) but also that once they are dead their elimination is (facilitated by SAP) swift and efficient.