Comparison between 5-aminolevulinic acid photodynamic diagnosis and narrow-band imaging for bladder cancer detection.

BACKGROUND: To compare 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) with narrow-band imaging (NBI) for cancer detection during transurethral resection of bladder tumour (TURBT). METHODS: Between June 2018 and October 2020, 114 patients and 282 lesions were included in the analysis. Patients were orally administered 5-ALA (20 mg/kg) 2 h before TURBT. The bladder was inspected with white light (WL), PDD, and NBI for each patient, and all areas positive by at least one method were resected or biopsied. The imaging data were then compared to the pathology results. RESULTS: The sensitivities of WL, PDD, and NBI for detecting urothelial carcinoma were 88.1%, 89.6%, and 76.2%, respectively. The specificity, positive predictive value, and negative predictive value for detecting urothelial carcinoma were 47.5%, 80.9%, and 61.3%, respectively, for WL; 22.5%, 74.5%, and 46.2%, respectively, for PDD; and 46.3%, 78.2%, and 43.5%, respectively, for NBI. PDD was significantly more sensitive than NBI for all lesions (p < 0.001) and carcinoma in situ (CIS) lesions (94.6% vs. 54.1%, p < 0.001). CONCLUSIONS: PDD can increase the detection rate of bladder cancer, compared to NBI, by greater than 10%. Therefore, 100% of CIS lesions can be detected by adding PDD to WL.

A single-arm, open-label, intervention study to investigate the improvement of glucose tolerance after administration of the 5-aminolevulinic acid (5-ALA) in the patients with mitochondrial diabetes mellitus.

BACKGROUND: Mitochondrial diabetes mellitus (MDM) is characterized by maternal inheritance, progressive neurosensory deafness, insulin secretory disorder, and progressive microvascular complications. Mitochondria are critical organelles that provide energy in the form of adenosine triphosphate (ATP). An impairment of ATP production in pancreatic ß cells is regarded as the main cause of the insulin secretory disorder in patients with MDM, and these patients require insulin replacement therapy early after the diagnosis. The amino acid 5-aminolevulinic acid (5-ALA), a precursor of heme metabolites, is a non-proteinogenic δ amino acid synthesized in mitochondria. An addition of ferrous iron to 5-ALA enhances heme biosynthesis and increases ATP production through an upregulation of the respiratory complex. Several studies have reported that the administration of 5-ALA and ferrous iron to existing treatment improved the glycemic control in both patients with prediabetes and those with type 2 diabetes mellitus. The additional administration of 5-ALA and ferrous iron to MDM patients on insulin therapy may improve their insulin secretory capacity and glycemic control by improving their mitochondrial function. The findings of this study are expected to provide new treatment options for MDM and improve the patients' glycemic control and prognosis. METHODS/DESIGN: This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of treatment with 5-ALA plus sodium ferrous citrate (SFC) to patients with MDM on their glucose tolerance. A total of 5 patients with MDM will be administered 5-ALA/SFC (200 mg/d) for 24 weeks. We will perform a 75-g oral glucose tolerance test before and at 24 weeks after the start of this 5-ALA/SFC treatment to evaluate glucose-dependent insulin responses. DISCUSSION: To the best of our knowledge, this study will be the first assessment of the effects of 5-ALA/SFC in patients with MDM. This study will obtain an evidence regarding the effectiveness and safety of 5-ALA/SFC for patients with MDM. TRIAL REGISTRATION: This study was registered with the University Hospital Medical Information Network (UMIN000040581) on July 1, 2020 and with the Japan Registry of Clinical Trials (jRCTs071200025) on August 3, 2020.

5-amino levulinic acid inhibits SARS-CoV-2 infection in vitro.

The current COVID-19 pandemic requires urgent development of effective therapeutics. 5-amino levulinic acid (5-ALA) is a naturally synthesized amino acid and has been used for multiple purposes including as an anticancer therapy and as a dietary supplement due to its high bioavailability. In this study, we demonstrated that 5-ALA treatment potently inhibited infection of SARS-CoV-2, a causative agent of COVID-19, in cell culture. The antiviral effects could be detected in both human and non-human cells, without significant cytotoxicity. Therefore, 5-ALA is worth to be further investigated as an antiviral drug candidate for COVID-19.

5-Aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) ameliorated liver injury in a murine acute graft-versus-host disease model by reducing inflammation responses through PGC1-α activation.

Acute graft-versus-host disease (aGvHD) remains lethal as a life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). Inflammatory responses play an important role in aGvHD. 5-Aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) has been widely reported to have a major effect on the anti-inflammatory response; however, these effects in aGvHD models have never been reported. In this study, a murine aGvHD model was developed by transferring spleen cells from donor B6/N (H-2kb) mice into recipient B6D2F1 (H-2kb/d) mice. In addition to evaluating manifestations in aGvHD mice, we analyzed the serum ALT/AST levels, liver pathological changes, infiltrating cells and mRNA expression of inflammation-related cytokines and chemokines. 5-ALA/SFC treatment significantly ameliorated liver injury due to aGvHD and decreased the population of liver-infiltrating T cells, resulting in a reduced expression of pro-inflammatory cytokines and chemokines. Furthermore, the mRNA expression proliferator-activated receptor-γcoactivator (PGC-1α) was enhanced, which might explain why 5-ALA/SFC treatment downregulates inflammatory signaling pathways. Our results indicated that 5-ALA/SFC can ameliorate liver injury induced by aGvHD through the activation of PGC-1α and modulation of the liver mRNA expression of inflammatory-related cytokines and chemokines. This may be a novel strategy for treating this disease.

Metronomic photodynamic therapy using an implantable LED device and orally administered 5-aminolevulinic acid.

Metronomic photodynamic therapy (mPDT) is a form of PDT that induces cancer cell death by intermittent continuous irradiation with a relatively weak power of light for a long duration (several days). We previously developed a wirelessly powered, fully implantable LED device and reported a significant anti-tumor effect of mPDT. Considering application in clinical practice, the method used for repeated administrations of photosensitizers required for mPDT should not have a high patient burden such as the burden of transvenous administration. Therefore, in this study, we selected 5-aminolevulinic acid (ALA), which can be administered orally, as a photosensitizer, and we studied the antitumor effects of mPDT. In mice with intradermal tumors that were orally administered ALA (200 mg/kg daily for 5 days), the tumor in each mouse was simultaneously irradiated (8 h/day for 5 days) using a wirelessly powered implantable green LED device (532 nm, 0.05 mW). Tumor growth in the mPDT-treated mice was suppressed by about half compared to that in untreated mice. The results showed that mPDT using the wirelessly powered implantable LED device exerted an antitumor effect even with the use of orally administered ALA, and this treatment scheme can reduce the burden of photosensitizer administration for a patient.

5-Aminolaevulinic acid patch photodynamic therapy for the treatment of actinic keratoses: preliminary results from an Italian study in the real-life setting.

BACKGROUND: Photodynamic therapy (PDT) is recommended for both lesion and field therapy of actinic keratoses (AKs). The 5-aminolaevulinic acid (5-ALA) patch PDT is indicated for the treatment of isolated mild AKs (≤1.8 cm) on the face and bald scalp. It was demonstrated to be effective and safe in clinical trials with a good tolerability profile. METHODS: In this retrospective multicenter real-life study, 33 patients with a total of 99 AKs of the scalp, face, ears, and/or hands and 2 actinic cheilitis were treated with one treatment session of 5-ALA patch PDT with a red light source (total dose of 37 J/cm2). RESULTS: Overall, 12 weeks after treatment, 68/99 (69%) lesions were completely cleared. Complete response was obtained in 82% of AKs on the ears, 78% on the face, 57% on the hands, and 56% on the scalp and in the two actinic cheilitis. The treatment was very effective on grade I AKs, cleared in 87% of the cases and less efficient on grade II-III lesions, cleared in 47% of the cases. 5-ALA patch PDT was well tolerated with a good to excellent cosmetic outcome in 97% of the patients and with 94% of the patients being satisfied or very satisfied with the treatment. CONCLUSIONS: Our results confirm that 5-ALA patch PDT is a good option for AK treatment in clinical practice, it is easy to use, effective and well tolerated even in difficult-to-treat-areas. Moreover, it has an excellent cosmetic outcome.

5-Aminolevulinic Acid-Guided Surgery for Recurrent Supratentorial Pediatric Neoplasms.

BACKGROUND: The use of 5-aminolevulinic acid (5-ALA) in pediatric neuro-oncology is considered off-label, and little data are available on its use in tumor recurrence surgery. Here we present our experience with 5-ALA fluorescence-guided surgery for recurrent supratentorial tumors in the pediatric population. METHODS: Eleven pediatric patients presenting with recurrence of a supratentorial high-grade malignancy (5 glioblastoma [GBM], 6 non-GBM) underwent 5-ALA-assisted surgery. Biopsy specimens were obtained from pathological and normal-appearing areas of the tumor margin. RESULTS: From the margin of the tumor displaying solid fluorescence, a total of 36 samples were obtained. All of these histological samples were found to harbor tumor cells. From areas of vague enhancement, a total of 49 histological samples were taken, of which 38 samples (77%) harbored tumor cells. There was no significant difference in the percentage of biopsy-positive vague fluorescent areas between the GBM cases (80%) and non-GBM cases (75%). A total of 59 biopsy specimens were taken from the tumor margin that appeared completely negative for fluorescence. On analysis, 24 (40.7%) of these specimens demonstrated tumor cells. There was no significant difference in the number of false-negative biopsies between the GBM group (40%) and the non-GBM group (41%). CONCLUSIONS: The positive predictive value of solid fluorescence is high in recurrent disease but is substantially lower in areas of vague fluorescence. The rate of false-negative fluorescence is high. 5-ALA should be considered as an adjuvant in revision surgery with the aforementioned caveats in mind.

5-aminolevulinic acid-based photodynamic therapy associated with Itraconazole successfully treated a case of chromoblastomycosis.

Chromoblastomycosis (CBM) is a prevalent implantation fungal infection. Patients with CBM show chronic granulomatous hyperplasia with ulcers and exudation. It may cause incapacity for labor in some severe clinical forms and it is often refractory to antifungal therapies. There is no optimal treatment. Here we report a case of a 71-year-old male farmer with refractory CBM who was successfully treated with 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) and Itraconazole in 2 months. Clinical cure was achieved with no obvious side effects.

Newly formulated 5% 5-aminolevulinic acid photodynamic therapy on Candida albicans.

BACKGROUND: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them. METHODS: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm. RESULTS AND CONCLUSION: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.

A New Method for Percutaneous Drug Delivery by Thermo-Mechanical Fractional Injury.

BACKGROUND AND OBJECTIVES: Percutaneous drug delivery (PDD) is a means of increasing the uptake of topically applied agents into the skin. Successful delivery of a photosensitizer into the skin is an important factor for effective photodynamic therapy. To evaluate the efficacy of pretreatment by thermomechanical fractional injury (TMFI) (Tixel®, Novoxel®, Israel) at low-energy settings in increasing the permeability of the skin to a known hydrophilic-photosensitizer medication, 5-amino-levulinic-acid hydrochloride (ALA) in compounded 20% ALA gel. To compare the effect of TMFI on ALA permeation into the skin in compounded gel to three commercial photosensitizing medications in different vehicles: ALA microemulsion gel, methyl-amino-levulinic-acid hydrochloride (MAL) cream, and ALA hydroalcoholic solution. STUDY DESIGN/MATERIALS AND METHODS: Five healthy subjects were treated in two separate experiments and on a total of 136 test sites, with four topical photosensitizer preparations as follows: compounded 20% ALA gel prepared in a good manufacturing practice (GMP)-certified pharmacy (Super-Pharm Professional, Israel), 10% ALA microemulsion gel (Ameluz®, Biofrontera Bioscience GmbH, Leverkusen, Germany), 16.8% MAL cream (Metvix®, Galderma, Lausanne, Switzerland), and 20% ALA hydroalcoholic solution (Levulan Kerastick®, DUSA Pharmaceuticals, Inc., Wilmington, MA, USA). The dermal sites were pretreated by Tixel® (Novoxel® Ltd., Israel) prior to topical drug application. One site was untreated to serve as control. Protoporphyrin IX (PpIX) fluorescence intensity readouts were taken immediately and 1, 2, 3, 4, and 5 hours posttreatment. RESULTS: The highest average PpIX fluorescence intensity measurements were obtained for the compounded 20% ALA gel following pre-treatment by TMFI at 6 milliseconds pulse duration. After 2 and 3 hours, TMFI-treated sites exhibited an increased hourly rate in readouts of FluoDerm units, which were 156-176% higher than the control rates (P ≤ 0.004). TMFI pre-treatment did not enhance the percutaneous permeation of either ALA or MAL following the microemulsion gel, hydroalcoholic solution, and cream applications. CONCLUSIONS: Pretreatment with low-energy TMFI at a pulse duration of 6 milliseconds increased the percutaneous permeation of ALA linearly over the first 5 hours from application when the compounded 20% ALA gel was used. Formulation characteristics have substantial influence on the ability of TMFI pretreatment to significantly increase the percutaneous permeation of ALA and MAL. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Characterization of plasma-derived protoporphyrin-IX-positive extracellular vesicles following 5-ALA use in patients with malignant glioma.

BACKGROUND: Malignant gliomas are rapidly progressive brain tumors with high mortality. Fluorescence guided surgery (FGS) with 5-aminolevulinic acid (5-ALA) provides fluorescent delineation of malignant tissue, which helps achieve maximum safe resection. 5-ALA-based fluorescence is due to preferential accumulation of the fluorophore protoporphyrin-IX (PpIX) in malignant glioma tissue. Additionally, gliomas cells release extracellular vesicles (EVs) which carry biomarkers of disease. Herein, we performed animal and human studies to investigate whether 5-ALA dosed glioma cells, in vitro and in vivo, release PpIX positive EVs in circulation which can be captured and analyzed. METHODS: We used imaging flow cytometry (IFC) to characterize PpIX-positive EVs released from 5-ALA-dosed glioma cells, glioma-bearing xenograft models, as well as patients with malignant glioma undergoing FGS. FINDINGS: We first show that glioma cells dosed with 5-ALA release 247-fold higher PpIX positive EVs compared to mock dosed glioma cells. Second, we demonstrate that the plasma of glioma-bearing mice (n = 2) dosed with 5-ALA contain significantly higher levels of circulating PpIX-positive EVs than their pre-dosing background (p = 0.004). Lastly, we also show that the plasma of patients with avidly fluorescent tumors (n = 4) undergoing FGS contain circulating PpIX-positive EVs at levels significantly higher than their pre-dosing background (p = 0.00009) and this rise in signal correlates with enhancing tumor volumes (r 2  = 0.888). INTERPRETATION: Our findings highlight the potential of plasma-derived PpIX-positive EV-based diagnostics for malignant gliomas, offering a novel liquid biopsy platform for confirming and monitoring tumor status.

A case series pilot study on the combination of 5-aminolevulinic acid and photodynamic therapy (ALA-PDT) for treatment of vitiligo

Abstract: Background: To study the effective therapeutic concentration, drug application duration, irradiation duration and irradiation dosage of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for treating vitiligo and observe its clinical efficacy. Objective: To assess the clinical efficacy of ALA-PDT for treating vitiligo. Methods: ALA with different drug concentrations, drug application durations, irradiation durations and irradiation dosages were adopted to treat skin lesions caused by vitiligo to determine the effective drug concentration, drug application duration, irradiation duration and irradiation dosage for treating three vitiligo volunteers and observe the therapeutic results. Results: The clinical trial suggested that ALA at a drug concentration of 1.5%, drug application duration for 3 hours, irradiation dosage of 80mw/cm2 and irradiation duration for 20 min was effective in treating vitiligo. Under these parameters, ALA-PDT was effective to the three vitiligo volunteers, with mild pain and feeling of burning but no other adverse reaction during treatment. Study limitations: Due to the small sample size in this study for the effectiveness of PDT in treating vitiligo and the potential variations in the efficacy for treating the disease at different areas, further studies shall be conducted for confirmation. Conclusions: ALA with a drug concentration at 1.5%, drug application duration for 3 hours, irradiation dosage of 80 mw/cm2 and irradiation duration for 20 min is effective in treating vitiligo. Therefore, ALA-PDT is safe and effective in treating the disease, with minor adverse events, providing a new method for treating vitiligo in the future.

Tumor-targeting core-shell structured nanoparticles for drug procedural controlled release and cancer sonodynamic combined therapy.

Combination therapy with multiple drugs or/and multiple assistant treatments has become a hot spot in cancer therapy. In this study, a new type of core-shell structured dual-drug delivery system based on poly (lactic-co-glycolic acid) (PLGA, inner cores) and hyaluronic acid (HA, outer shells) was constructed. Firstly, HA was conjugated to PLGA for preparation of HA-PLGA block copolymer. Secondly, 5-amino levulinic acid (ALA) was connected to PLGA through a pH-sensitive hydrazone bond for synthesization of PLGA-HBA-ALA. Finally, the core-shell structured nanoparticles (HA-PLGA@ART/ALA NPs) were constructed by self-assembled method for artemisinin (ART) loading in PLGA cores. In this co-delivery system, ALA and ART can be released in a manner of procedural controlled release. ALA was released from the NPs at first though the pH sensitive hydrazone bond cleavage in order to generate protoporphyrin IX (PpIX) for heme formation. And the increase of heme can effectively improve the curative effect of the subsequent released ART. Furthermore, this system has also shown obvious sonodynaimc activity which can be used for cancer sonodynamic combination therapy. The in vitro and in vivo anticancer results demonstrate that HA-PLGA@ART/ALA delivery system could provide a prospective comprehensive treatment strategy for cancer therapy.

Topical formulations of delta-aminolevulinic acid for the treatment of actinic keratosis: Characterization and efficacy evaluation.

Actinic keratosis (AK) is a pre-cancerous disease, with worldwide increasing incidence, which consists in squamous cutaneous lesion caused by excessive exposure to ultraviolet radiation. An established treatment option is photodynamic therapy (PDT), based on light, oxygen and a photosensitizer. The most widely used is 5-aminolevulinic acid (ALA) which however, being a hydrophilic molecule, has difficultly penetrating the skin to achieve the desired therapeutic effect. To solve this limit, the present study provides for the development of three galenic gel formulations (Natrosol, Sepigel and Carbopol) containing 10% w/w of ALA for the treatment of AK with PDT and their comparison with a lipophilic cream used in the Hospital. The aim of this study is to offer an appealing topical treatment that improves patients' observance and compliance. Formulations were characterized in terms of chemical, physical and microbiological stability, viscosity and pH. An HPLC-DAD analytical method was also developed and validated. Sepigel gel resulted the best gel formulation in terms of technological characteristics and stability. A comparative study between this gel and the lipophilic cream was assessed, by evaluating the therapeutic efficacy and the compliance of the patients.

The Invasive Region of Glioblastoma Defined by 5ALA Guided Surgery Has an Altered Cancer Stem Cell Marker Profile Compared to Central Tumour.

Glioblastoma, a WHO grade IV astrocytoma, is a highly aggressive and heterogeneous tumour that infiltrates deeply into surrounding brain parenchyma, making complete surgical resection impossible. Despite chemo-radiotherapy, the residual cell population within brain parenchyma post-surgery causes inevitable recurrence. Previously, the tumour core has been the focus of research and the basis for targeted therapeutic regimes, which have failed to improve survival in clinical trials. Here, we focus on the invasive margin as defined by the region with 5-aminolevulinic acid (5ALA) (GliolanTM) fluorescence at surgery beyond the T1 enhancing region on magnetic resonance imaging (MRI). This area is hypothesized to constitute unique microenvironmental pressures, and consequently be molecularly distinct to tumour core and enhancing rim regions. We conducted hematoxylin and eosin (H&E), array real time polymerase chain reaction (PCR), and immunohistochemistry staining on various intra-tumour regions of glioblastoma to determine molecular heterogeneity between regions. We analyzed 73 tumour samples from 21 patients and compared cellular density, cell proliferation, and the degree of vascularity. There is a statistically significant difference between the core, invasive margin and other regions for cell density (p < 0.001), cell proliferation (p = 0.029), and vascularity (p = 0.007). Aldehyde dehydrogenase 1 (ALDH1) and Nestin immunohistochemistry were used as a measure of stem-like properties, showing significantly decreased Nestin expression (p < 0.0001) in the invasive margin. Array PCR of the core, rim, and invasive regions showed significantly increased fibroblast growth factor (FGF) and ALDH1 expression in the invasive zone, with elevated hypoxia inducing factor 1-alpha (HIF1α) in the rim region, adjacent to the hypoxic core. The influence of varying microenvironments in the intra-tumour regions is a major key to understanding intra-tumour heterogeneity. This study confirms the distinct molecular composition of the heterogeneous invasive margin and cautions against purported therapy strategies that target candidate glioblastoma stem-like genes that are predominantly expressed in the tumour core. Full characterization of tumour cells in the invasive margin is critical, as these cells may more closely resemble the residual cell population responsible for tumour recurrence. Their unique nature should be considered when developing targeted agents for residual glioblastoma multiforme (GBM).

Glutaminase 2 expression is associated with regional heterogeneity of 5-aminolevulinic acid fluorescence in glioblastoma.

Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) is now a widely-used modality for glioblastoma (GBM) treatment. However, intratumoral heterogeneity of fluorescence intensity may reflect different onco-metabolic programs. Here, we investigated the metabolic mechanism underlying the heterogeneity of 5-ALA fluorescence in GBM. Using an in-house developed fluorescence quantification system for tumor tissues, we collected 3 types of GBM tissues on the basis of their fluorescence intensity, which was characterized as strong, weak, and none. Expression profiling by RNA-sequencing revealed 77 genes with a proportional relationship and 509 genes with an inverse relationship between gene expression and fluorescence intensity. Functional analysis and in vitro experiments confirmed glutaminase 2 (GLS2) as a key gene associated with the fluorescence heterogeneity. Subsequent metabolite profiling discovered that insufficient NADPH due to GLS2 underexpression was responsible for the delayed metabolism of 5-ALA and accumulation of protoporphyrin IX (PpIX) in the high fluorescence area. The expression level of GLS2 and related NADPH production capacity is associated with the regional heterogeneity of 5-ALA fluorescence in GBM.

Photodynamic diagnosis of visceral pleural invasion of lung cancer with a combination of 5-aminolevulinic acid and autofluorescence observation systems.

BACKGROUND: Visceral pleural invasion (PL) is a prognostic factor in lung cancer. In the lung, lymph flows along the pleura, in addition to the flow toward the pulmonary hilum just as the pulmonary arteries and veins run toward it. Even with the same tumor diameter, a PL1 or higher level of pleural invasion is indicative of a more advanced disease stage. Final diagnosis based on the PL level is made by pathological examination of excised specimens. However, if an intraoperative diagnosis can be established, proper selection of the surgical procedure can be made, and unnecessary surgeries for disseminated lesions can be avoided. We investigated optical diagnostic techniques for identifying the presence or absence of visceral pleural invasion in lung cancer by capitalizing on the phenomenon of 5-amino-levulinic acid (5-ALA) being metabolized to a photosensitizing substance or protoporphyrin IX within malignant tumors, generating red luminescence in response to excitation light. METHOD: This study included 38 patients with primary lung cancer who underwent surgery. They received 5-ALA (20mg/kg) orally 4h before surgery and then we assessed the presence or absence of pleural invasion using an autofluorescence observation system. At visceral pleural invasion sites, we were able to confirm tumor sites visualized in red with a clear border in contrast to the green autofluorescence generated in normal tissues. RESULT: Red luminescence could be confirmed in 100% of PL1-PL3 patients (14/14) and 41.6% of PL0 patients (10/24) with primary lung cancer. PL0 patients in whom visualization was possible were preoperatively diagnosed as having PL1 and many of them showed vascular channel invasion. The sensitivity, specificity, positive predictive value, and negative predictive value of this diagnostic technique were 100%, 58.0%, 63.1%, and 100%, respectively. Red fluorescence emission was observed significantly more often in pleural invasion cases. CONCLUSION: Accurate intraoperative diagnosis for visceral pleural invasion in lung cancer may contribute to determining the indications for limited operations such as segmental resection. In addition, accurate local diagnosis has the possibility of being applicable to photodynamic therapy.

Expression of coproporphyrinogen oxidase is associated with detection of upper gastrointestinal carcinomas by 5-aminolevulinic acid-mediated photodynamic diagnosis.

BACKGROUND: 5-Aminolevulinic acid is a precursor of photosensitizing protoporphyrin IX and has been applied for photodynamic diagnosis of brain and bladder tumors with few side effects. Although most upper gastrointestinal tumors can be detected during photodynamic diagnosis, some tumors containing signet-ring cells cannot be visualized. Here, we aimed to assess whether proteins involved in the absorbance, activation, and turnover of protoporphyrin IX altered the fluorescence signal in gastric cancer. METHODS: Aminolevulinic acid-mediated photodynamic diagnosis was performed in 23 lesions from 20 patients using an endoscope equipped with a blue laser light that caused red fluorescence emission of photosensitizing protoporphyrin IX. Red fluorescence signal and intensity was assessed during photodynamic diagnosis procedures. Lesions were resected by endoscopic and/or laparoscopic surgery, and specimens were immunostained and assessed for the expression of ATP-binding cassette sub-family G member 2, oligopeptide transporter-1, and coproporphyrinogen oxidase. RESULTS: Photodynamic diagnosis was negative in four cases (17.4%). Three cases of photodynamic diagnosis-negative lesions were signet-ring cell carcinomas, and only one case was differentiated adenocarcinoma (intestinal type). Twenty intestinal type, photodynamic diagnosis-positive lesions showed high expression of coproporphyrinogen oxidase, whereas signet-ring cell carcinomas were all negative. Oligopeptide transporter-1 immunoreactivity was significantly higher in tumors of intestinal type. ATP-binding cassette sub-family G member 2 expression tended to be higher in luminal surface tumors than in intestinal type tumors. CONCLUSION: Aminolevulinic acid-mediated photodynamic diagnosis provided good detection of upper gastrointestinal tumors of intestinal type but not diffuse type tumors, such as signet-ring cell carcinomas, possibly owing to coproporphyrinogen oxidase expression.