Real Clinical Practice of Combined Atezolizumab Plus Chemotherapy in Patients With Small Cell Lung Cancer

BACKGROUND/AIM

Atezolizumab, an anti-PD-L1 antibody, has been increasingly administered in combination with chemotherapy to patients with small cell lung cancer (SCLC). This study aimed to determine how patients with extensive disease (ED) -SCLC responded to atezolizumab with chemotherapy and found factors affecting long-term response and survival.

PATIENTS AND METHODS

This study focused on patients with SCLC who were treated with a combination of atezolizumab and chemotherapy in Japan between 2019 and 2023. Patient information and tumor response were analyzed, along with adverse events. We compared data and estimated survival probabilities.

RESULTS

In our clinical trial, 95 patients with SCLC who received this treatment had a median progression-free survival of 6.0 months and a median overall survival of 15.0 months. Immune-related adverse events were observed in 13.7% of the patients, with grade 3 or higher in 5.3%. The efficacy and immune-related adverse events associated with this treatment regimen were comparable to those reported in previous clinical trials. Progression-free survival >2 years was observed in a small number of patients (5.3%).

CONCLUSION

Our research will offer important insights for the future care of patients with extensive-stage SCLC by utilizing atezolizumab in combination with chemotherapy. Accumulation and confirmation of clinical practice results will have important implications for the future implementation of this therapy.

Inflammatory myofibroblastic tumor directly invading the right first rib treated with oral steroids: a case report

BACKGROUND

We present a case of an inflammatory myofibroblastic tumor cured with a short period of steroid administration, a treatment previously unreported for such cases.

CASE PRESENTATION

A 49-year-old man had a chief complaint of chest pain for more than 3 days. Computed tomography (CT) revealed a tumoral lesion suspected to have infiltrated into the right first rib and intercostal muscles, with changes in lung parenchymal density around the lesion. The maximal standardized uptake value on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography was high (16.73), consistent with tumor presence. CT-guided biopsy revealed an inflammatory myofibroblastic tumor with no distant metastases. Surgery was indicated based on the disease course. However, he had received an oral steroid before the preoperative contrast-enhanced CT scan due to a history of bronchial asthma, and subsequent CT showed that the tumor shrank in size after administration; he has been recurrence-free for more than a year.

CONCLUSIONS

Surgery is still the first choice for inflammatory myofibroblastic tumors, as the disease can metastasize and relapse; however, this condition can also be cured with a short period of steroid therapy.

Patient profiling to predict response to bronchial thermoplasty in patients with severe asthma

Bronchial thermoplasty is the only device-based nonpharmacological treatment approach for severe asthma. Current guidelines are cautious in recommending bronchial thermoplasty because of unknown patient response prediction. Recent research on bronchial thermoplasty includes up-to-date, state-of-the-art, and recent-advances reviews. However, these reviews provide a broad and general discussion on equipment, technique, patient selection, and patient management, with little evaluation of the predictors of a beneficial response. Predicting an optimal response to bronchial thermoplasty in patients with severe asthma remains elusive. The lack of reliable predictive markers means that bronchial thermoplasty remains a last-line treatment and makes profiling for predicting the response or efficacy a topic of study. Genetic changes are associated with airway remodeling. A gap in the literature exists regarding patient profiling to predict the response to bronchial thermoplasty in patients with severe asthma. Therefore, recently published omics data and genetic associations regarding the response to bronchial thermoplasty therapy should be reviewed. We present an up-to-date review of recent publications profiling the response to bronchial thermoplasty in patients with severe asthma.

Atezolizumab for EGFR-mutated Non-small Cell Lung Cancer Patients: An Observation Study in Ibaraki Group (ATTENTION-IBARAKI)

BACKGROUND/AIM

Atezolizumab, an anti-programed death-ligand 1 monoclonal antibody, targets programed death-ligand 1 expressed on cancer cells and antigen-presenting cells and is now commonly used in combination with chemotherapy. We conducted a study to clarify the efficacy of atezolizumab in epidermal growth factor receptor (EGFR)-mutated patients who are considered less responsive to immune checkpoint inhibitors.

PATIENTS AND METHODS

A retrospective review of patients with advanced non-small cell lung cancer (NSCLC) who received atezolizumab-containing therapy at 11 hospitals from April 2018 to March 2023 was performed.

RESULTS

Median progression-free survival and overall survival in 33 EGFR-mutated patients treated with atezolizumab monotherapy were 2.0 and 9.0 months, respectively, and those in 19 patients who received combined atezolizumab plus chemotherapy were 12.0 and 17.0 months, respectively. When comparing EGFR-mutated and EGFR-negative patients after propensity score matching, there were no significant differences in progression-free survival and overall survival between the two groups, whether atezolizumab monotherapy or combined atezolizumab plus chemotherapy. Among EGFR-mutated patients, being male was a significant favorable factor in both atezolizumab treatment groups. None of the EGFR-mutated patients had grade 5 immune-related adverse events.

CONCLUSION

Efficacy of atezolizumab in EGFR-mutated NSCLC patients could be comparable to that for EGFR-negative patients. To prolong the survival of EGFR-mutated NSCLC patients, appropriate selection and sequencing of EGFR for tyrosine kinase inhibitors, as well as immune checkpoint inhibitors, anti-tumor agents, and anti-angiogenic agents are important.

Atezolizumab Monotherapy for Non-small Cell Lung Cancer Patients: An Observational Study in Ibaraki Group (ATTENTION-IBARAKI)

BACKGROUND/AIM

Atezolizumab is a monoclonal antibody that targets programmed death-ligand 1 (PD-L1) expressed on cancer cells derived from various organs and antigen-presenting cells and is currently commonly used in combination with chemotherapy. We conducted a study to clarify the current status of response to atezolizumab monotherapy in clinical practice and clarify the factors that contribute to long-term response and survival.

PATIENTS AND METHODS

We conducted a retrospective review of patients with advanced non-small cell lung cancer (NSCLC) treated with atezolizumab monotherapy from April 2018 to March 2023 at 11 Hospitals.

RESULTS

The 147 patients evaluated had a progression-free survival (PFS) of 3.0 months and an overall survival of 7.0 months. Immune-related adverse events of any grade were observed in 13 patients (8.8%), grade 3 or higher in nine patients (6.1%), and grade 5 with pulmonary toxicity in one patient (0.7%). Favorable factors related to PFS were 'types of NSCLC other than adenocarcinoma'. Favorable factors for overall survival were 'performance status 0-1' and 'treatment lines up to 3'. There were 16 patients (10.9%) with PFS >1 year. No characteristic clinical findings were found in these 16 patients compared to the remaining 131 patients.

CONCLUSION

Efficacy and immune-related adverse events of NSCLC patients associated with atezolizumab monotherapy were comparable to those of previous clinical trial results. Knowledge of characteristics of patients who are most likely to benefit from atezolizumab monotherapy is a crucial step towards implementing appropriate prescribing.

A case of epidermal growth factor receptor tyrosine kinase inhibitor effectiveness in epidermal growth factor receptor mutation-positive squamous cell carcinoma

A 71-year-old non-smoker woman was admitted to our hospital because of left front chest pain. A computed tomography scan showed a large mass of >7.0 cm in the lower left part of the lung and multiple organ metastases in the liver, brain, bone, and left adrenal gland. Pathological analysis of a resected specimen obtained by bronchoscopy revealed keratinization. In addition, p40 was positive and thyroid transcription factor-1, synaptophysin, CD56, and chromogranin A were negative by immunohistochemistry. Programmed cell death ligand 1 expression was 1%-10%, and exon 19 deletion was detected. We diagnosed the patient with stage IVB lung squamous cell carcinoma and administered osimertinib. Osimertinib was later replaced with afatinib because of grade 3 skin rash. Overall, the size of the cancer was decreased. Furthermore, her symptoms, laboratory data, and computer tomographic findings markedly improved. In summary, we experienced a case of epidermal growth factor receptor-positive lung squamous cell carcinoma that was responsive to epidermal growth factor receptor tyrosine kinase inhibitors.

Investigation On Applicability of Subchannel Analysis Code Asfre to Thermal Hydraulics Analysis in Fuel Assembly with Inner Duct Structure of Sodium Cooled Fast Reactor

In the design study of an advanced sodium-cooled fast reactor (Advanced-SFR) in Japan Atomic Energy Agency (JAEA), the use of a specific fuel assembly (FA) with an inner duct structure called FAIDUS has been investigated to enhance safety of Advanced-SFR. Due to the asymmetric layout of fuel rods by the inner duct, it is necessary to estimate the temperature distribution to confirm feasibility of FAIDUS. In JAEA, an in-house subchannel analysis code named ASFRE has been developed as a FA design tool. For the typical FAs, the numerical results of ASFRE were validated by comparisons with experimental data. As for the FAIDUS, confirmation of validity of the numerical results by ASFRE was not enough because the reference data on the thermal hydraulics in FAIDUS have not been obtained by the mock-up experiment, yet. In this paper, therefore, the code-to-code comparisons with numerical results of ASFRE and those of an in-house CFD code named SPIRAL was applied making further discussion on applicability of ASFRE to the thermal hydraulics analysis in FAIDUS. Thermal hydraulic analyses of a typical FA and FAIDUS at high and low flow rate conditions were conducted. The applicability of ASFRE was indicated through the confirmation of the consistency of mechanism on appearance of the specific temperature distributions between the numerical results by ASFRE and those by SPIRAL. In addition, the necessity of modification on the empirical constants in numerical model of ASFRE to improve the predictive accuracy was indicated.

Prognostic Implication of PD-L1 Expression on Osimertinib Treatment for EGFR-mutated Non-small Cell Lung Cancer

BACKGROUND/AIM

Real-world data on the clinical outcomes of first-line osimertinib treatment for non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations is lacking. This study aimed to reveal the treatment outcomes and prognostic factors of osimertinib as first-line therapy in clinical practice settings.

PATIENTS AND METHODS

We retrospectively evaluated clinical outcomes of patients with EGFR-mutated NSCLC treated with osimertinib as first-line therapy across 12 institutions in Japan between August 2018 and March 2020.

RESULTS

Among 158 enrolled patients, the objective response rate (ORR) was 68%, and the estimated median progression-free survival (PFS) was 17.1 months [95% confidence interval (CI)=14.5-19.7]. Subgroup analysis showed that PFS in the group with high programmed death-ligand 1 (PD-L1) expression was significantly shorter than that in groups with low or no PD-L1 expression (10.1 vs. 16.1 vs. 19.0 months; p=0.03). Univariate and multivariate analyses demonstrated that high PD-L1 expression was the only independent adverse prognostic factor of osimertinib outcome related to PFS (hazard ratio=2.71; 95%CI=1.26-5.84; p=0.01). In terms of anti-tumor response, there was no statistically significant correlation between PD-L1 expression and the ORR (67% vs. 76% vs. 65%; p=0.51). No significant correlation was also found between PD-L1 and the incidence of de novo resistance to osimertinib (p=0.39).

CONCLUSION

Although PD-L1 expression was not associated with either the ORR or frequency of de novo resistance, high PD-L1 expression could be an independent adverse prognostic factor related to PFS in osimertinib treatment.

Influence of the MCT1-T1470A polymorphism (rs1049434) on repeated sprint ability and blood lactate accumulation in elite football players: a pilot study

PURPOSE

The aim of this study is to investigate the influence of the MCT1 T1470A polymorphism (rs1049434) on repeated sprint ability (RSA) and lactate accumulation after RSA testing.

METHODS

Twenty-six elite Italian male football players (age: 17.7 ± 0.78 years; height: 179.2 ± 7.40 cm; weight: 72.1 ± 5.38 kg) performed RSA testing (6 × 30-m sprints with an active recovery between sprints), and lactate measurements were obtained at 1, 3, 5, 7, and 10 min post-exercise. Genotyping for the MCT1 T1470A polymorphism was performed using PCR.

RESULTS

Genotype distributions were in Hardy-Weinberg equilibrium, being 42% wildtype (A/A), 46% heterozygotes (T/A), and 12% mutated homozygotes (T/T). Significant differences between genotypic groups were found in the two final sprint times of the RSA test. Under a dominant model, carriers of the major A-allele (Glu-490) in the dominant model showed a significantly lower sprint time compared to footballers with the T/T (Asp/Asp) genotype (5th Sprint time: A/A + T/A = 4.60 s vs TT = 4.97 s, 95% CI 0.07-0.67, p = 0.022; 6th Sprint: A/A + T/A = 4.56 s vs T/T = 4.87 s, 95% CI 0.05-0.57, p = 0.033).

CONCLUSIONS

The T1470A (Glu490Asp) polymorphism of MCT1 was associated with RSA. Our findings suggest that the presence of the major A-allele (Glu-490) is favourable for RSA in football players.

Prognostic impact of heart mate risk score among elderly heart failure patients with non-responder for cardiac resynchronization therapy

Background

For patients with severe heart failure (HF) who are not eligible for transplantation, there is destination therapy (DT) that uses a continuous flow left ventricular assist device (LVAD). Implantation of LVAD improves HF and can be expected to improve the prognosis of life. Elderly refractory HF patients with non-responders for cardiac resynchronization therapy (CRT) may benefit from LVAD as DT. In considering indications of LVAD as DT for the elderly in Japan, conditions such as a low risk of Heart Mate Risk Score (HMRS) have been raised. HMRS has been shown to correlate with mortality in the cohort of LVAD patients enrolled in the Heartmate II trials.

Purpose

Because elderly CRT non-responder refractory HF patients are not indicated for transplantation and may benefit from LVAD as DT in Japan, we aimed to investigate the HMRS and prognosis among elderly CRT non-responders.

Methods

Of 467 patients underwent CRT implantation between 2000 and 2015, 157 were aged 65–75 years old. Of which 59 patients who could be determined to be non-responders based on echocardiographic data were included in this study. The primary endpoint was all-cause mortality, the secondary was readmission for HF and appropriate implantable cardioverter defibrillator (ICD) therapy.

Results

The patients' mean age was 68 years, males were 71%. The mean serum creatinine value was 1.1 mg/dl, albumin was 3.8 mg/dl, and BNP was 383 pg/ml. The mean left ventricular ejection fraction (LVEF) was 26%. The subjects were divided into 3 groups according to HMRS. The average of HMRS was 2.2, the low-risk group included 17 (29%) patients, the medium was 22 (37%), and the high was 20 (34%). There was no significant difference in age, LVEF, BNP, and NYHA functional classification at the time of CRT implantation between three groups. In the low-risk group, creatinine and INR were significantly lower, and albumin was significantly higher compared to the high-risk group. BNP tended to be lower in the low-risk group, but there was no significant difference. The mortality rate by HMRS was 12% in the low-risk group, 36% in the medium-risk group, and 50% in the high-risk group. On the Kaplan-Meier analysis, the low-risk group had a significantly lower mortality rate than the high-risk group (Figure). Furthermore, focusing on HF readmission, the rate of readmission was 59% in the low-risk group, 86% in the medium -risk group, and 65% in the high-risk group, and there was no significant difference between three groups. There was also no significant difference in appropriate ICD therapy between three groups.

Conclusion

Approximately 30% of elderly non-responders of CRT are in the low-risk group by HMRS and their mortality was lower than that of the other two groups. These elderly CRT non-responder patients might be considered a candidate for DT in Japan.

Funding Acknowledgement

Type of funding sources: None.

Transcriptome genetic differences between responders and non-responders before bronchial thermoplasty

BACKGROUND

Bronchial thermoplasty (BT) is an endoscopic therapy used for the treatment of refractory asthma. Some predictive factors, for example the number of activations and severity of disease at baseline, have been used to determine the effectiveness of BT in treating patients with asthma. The aim of the present study was to comprehensively analyze RNA samples from the airway bronchial tissues of patients with severe asthma treated by BT, and to characterize each patient as a BT responder or non-responder.

METHODS

Eight patients with severe asthma scheduled to undergo BT and bronchus biopsies were recruited before the procedures were conducted. Extracted RNA samples from bronchial tissues were sequenced and differential gene expression analysis was carried out.Results/discussion: Subjects with Asthma Quality of Life Questionnaire score changes ≥0.5 for a period of 12 months were considered BT responders. Non-responders had score changes <0.5 for 12 months. Histopathology findings were similar to those reported previously, and no significant differences in the expression of α-smooth muscle actin and protein gene product 9.5 were observed between responders and non-responders. Transcriptome analysis at baseline identified 67 genes that were differentially expressed between responders and non-responders, including SLPI, MMP3, and MUC19, which were upregulated in responders. Although the differentially expressed gene products may have conflicting effects, genes in the airway epithelium and extracellular matrix of patients with severe asthma may determine the BT response. Our results identified possible transcriptomic changes that could be used to identify BT responders.

Low prevalence of maternal microchimerism in peripheral blood of Japanese children with type 1 diabetes

AIM

To clarify the prevalence and degree of maternal microchimerism in Japanese children with type 1 diabetes, as well as its effect on phenotypic variation.

METHODS

We studied 153 Japanese children with type 1 diabetes, including 124 children positive for β-cell autoantibodies, and their 71 unaffected siblings. The number of circulating microchimeric cells per 10⁵ host cells was estimated by the use of quantitative-polymerase chain reaction targeting non-transmitted maternal human leukocyte antigen alleles. The results were compared to previous data from white European people. Phenotypic comparison was performed between maternal microchimerism carriers and non-carriers with diabetes.

RESULTS

Maternal microchimerism was detected in 15% of children with autoantibody-positive type 1 diabetes, 28% of children with autoantibody-negative type 1 diabetes, and 16% of unaffected siblings. There were no differences in the prevalence or levels of maternal microchimerism among the three groups or between the children with type 1 diabetes and their unaffected siblings. Furthermore, maternal microchimerism carriers and non-carriers exhibited similar phenotypes.

CONCLUSIONS

Maternal microchimerism appears to be less common in Japanese children with type 1 diabetes than in white European people. Our data indicate that maternal microchimerism is unlikely to be a major trigger or a phenotypic determinant of type 1 diabetes in Japanese children and that the biological significance of maternal microchimerism in type 1 diabetes may differ among ethnic groups.

Treatment of Patients With Non-small-cell Lung Cancer With Uncommon EGFR Mutations in Clinical Practice

BACKGROUND/AIM

To describe real clinical outcomes in patients with non-small cell lung cancer who have uncommon epidermal growth factor receptor (EGFR) mutations.

MATERIALS AND METHODS

We performed a retrospective chart review from 15 medical institutes that cover a population of three million people from April 2008 to March 2019.

RESULTS

There were 102 patients with uncommon EGFR mutation. Progression-free survival (PFS) tended to be longer in patients receiving afatinib compared with first-generation EGFR tyrosine kinase inhibitors. PFS in patients treated with afatinib or osimertinib was significantly longer than in patients treated with gefitinib or erlotinib (p=0.030). Multivariate analysis also revealed the contribution of afatinib or osimertinib to increased survival. In patients with exon 20 insertions, chemotherapy was efficacious.

CONCLUSION

In treating patients with uncommon EGFR mutations, our results indicate longer-term survival might be achieved with second-generation or later TKIs and cytotoxic chemotherapeutic drugs.

Low-Dose Erlotinib Treatment in Elderly or Frail Patients With EGFR Mutation-Positive Non-Small Cell Lung Cancer: A Multicenter Phase 2 Trial

Importance

Although the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors for EGFR gene mutation-positive non-small cell lung cancer is well established, optimal dosing remains to be established, especially in elderly or frail patients.

Objective

To investigate the efficacy and safety of low-dose erlotinib in elderly or frail patients with EGFR mutation-positive non-small cell lung cancer.

Design, Setting, and Participants

Single-arm phase 2 trial with the Southwest Oncology Group (SWOG) 2-stage design that enrolled frail patients from 21 Japanese institutions after meeting the inclusion criteria. Chemotherapy-naive patients with EGFR-activating mutation-positive non-small cell lung cancer who were considered frail based on age, the Charlson Comorbidity Index, and Eastern Cooperative Oncology Group performance status were eligible for the study.

Interventions

Patients were initially administered 50 mg/d erlotinib for 4 weeks, which was modified based on response or adverse events. Dose increase was permitted for patients with stable disease after 4 weeks.

Main Outcomes and Measures

The primary end point was the independent review committee-confirmed objective response rate (ORR) at the dose of 50 mg/d. The study also evaluated the pharmacokinetics of low-dose erlotinib and influence of ABCB1 gene polymorphisms.

Results

Eighty patients were enrolled, with a median (range) age of 80 (49-90) years; 54 (68%) were men. An independent review committee confirmed a significant ORR of 60.0% (90% CI, 50.2%-69.2%). The disease control rate was 90.0% (90% CI, 82.7%-94.9%), median progression-free survival was 9.3 months (95% CI, 7.2-11.4 months), and median overall survival was 26.2 months (95% CI, 21.9-30.4 months). Mild adverse events were observed in some participants, with few patients exhibiting grade 3 or greater adverse events. Low-dose erlotinib treatment was temporarily suspended for 10 patients owing to adverse events. Five of 80 patients (6%) had their erlotinib dose reduced to 25 mg because of oral mucositis, paronychia, erythema multiforme, diarrhea, and anorexia. Two patients discontinued treatment because of adverse events (cutaneous ulcer and bone infection, and oral mucositis, respectively). There were no cases of interstitial lung disease or treatment-related deaths. The median (range) erlotinib plasma concentration was measured at 685 (153-1950) ng/mL. Seventy-three patients discontinued study treatment owing to disease progression (n = 60), death (n = 3), AEs (n = 4), and patient requests (n = 6). No clear association was observed between the pharmacokinetics of low-dose erlotinib and the treatment outcome.

Conclusions and Relevance

Low-dose erlotinib appears to be safe and effective in elderly or frail patients with EGFR mutation-positive non-small cell lung cancer and can be a valid treatment option.

Trial Registration

UMIN-CTR Identifier: UMIN000015949.

Clinicopathological Features in Elderly ALK-rearranged Non-small Cell Lung Cancer Patients

AIM

To clarify the clinicopathological features in elderly anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

A retrospective study was performed in 129 ALK rearranged NSCLC patients diagnosed between April 2008 and March 2019 in fifteen Institutions of the Ibaraki prefecture, Japan.

RESULTS

Median age of patients was 63 years. In 59 patients aged 65 and older, the proportions of patients with advanced stage and those treated with ALK-tyrosine kinase inhibitor (TKI) were lower than those younger than 65 years. There was no difference in overall survival (OS) between the two age groups. Among the elderly patients, no difference was observed in OS between the patients aged 65-69 and those aged 70 and older. In 89 patients treated with TKI, no significant differences were observed in the progression-free survival of TKIs and OS between patients aged 65 and older and those younger than 65, respectively.

CONCLUSION

Evaluation of ALK gene status and TKI treatment are desirable even for elderly patients.

Serum CEA and CYFRA Levels in ALK-rearranged NSCLC Patients: Correlation With Distant Metastasis

AIM

To clarify the correlation between serum levels of carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA) and metastasis and survival in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

CEA and CYFRA levels in 131 ALK-rearranged NSCLC patients were determined using fluorescence in situ hybridization (FISH), real time-reverse transcription polymerase chain reaction, and immunohistochemistry, using biopsy specimens, cytology specimens, and plasma specimens. Cut-off value of each marker was determined as 10 ng/ml.

RESULTS

In logistic regression analysis, higher levels of both markers had a positive relationship with bone metastases, and higher levels of CYFRA was relevant to liver metastases, and multiple-organ metastases. However, these markers were not proven to be poor prognostic factors in Cox's proportional model analysis.

CONCLUSION

Elevated serum CEA and CYFRA levels seem to provide useful clinical information about presence of bone and liver metastasis and multiple-organ metastases, although they were not a powerful indicator of prognosis. These two markers may suggest the extension of metastasis and would be helpful in considering treatment options.

Pneumonitis Due to Oren-gedoku-to (Coptis Detoxifying Decoction)

A 54-year-old man started to take oren-gedoku-to (coptis detoxifying decoction) because he was experiencing chronic hot flashes, night sweats and insomnia. He developed a high fever from the day of intake. At day 17, he stopped taking oren-gedoku-to because of malaise and chills, and he was admitted to our hospital. Drug-induced pneumonitis was suspected, and all drugs were stopped. Consequently, his symptoms, laboratory data and chest X-ray findings markedly improved. The results of a lymphocyte stimulation test were positive for oren-gedoku-to and one of its components, ougon (Baikal skullcap). Based on these findings, we diagnosed him with pneumonitis caused by ougon.

P3359Myocardial flow reserve using 13N ammonia PET for detection of cardiac allograft vasculopathy in heart transplant patients

Purpose

Risk stratification and early detection of cardiac allograft vasculopathy (CAV) are essential in heart transplantation patients. CAV is associated with poor outcome in the chronic phase after heart transplantation. CAV presents a diffuse vascular involvement and has been difficult to noninvasively diagnose by the lack of a sensitive method to detect developing vascular pathology in the allograft. The present study investigates the ability of 13N-ammonia PET for detection of CAV in heart transplant patients.

Methods

Data of adenosine-stress 13N-ammonia PET imaging for thirty-one patients (mean age, 39 years-old) after 11 + 7 years from transplant was analyzed. Five patients had undergone percutaneous coronary intervention (PCI), and the remaining 26 patients had no history of definite myocardial ischemia. Myocardial flow was generated from the time activity curve of left ventricle input and myocardial uptake using 3-compartment model and the first 2 minutes' dataset of list-mode acquisition. Global - myocardial flow reserve (MFR) was calculated by stress to rest flow ratio. Patient with global-MFR <2.0 was defined as significant decrease. Summed difference score (SDS) was used as an estimate for the extent of ischemia, and the patient showing SDS >2 was identified as those having significant ischemia.

Results

The mean Global-MFR of our subjects were 2.3 (1.2 to 3.9). MFR using 13N-ammonia PET significantly decreases in one third of heart transplant patients in chronic stage. Eleven patients with Global-MFR <2.0 (35%) were observed, and eight of them had no history of clinical myocardial ischemia. The proportion of patients with a history of PCI is 18% in patients with Global-MFR <2.0 (vs 5%, p=0.210). Moreover, there were eight patients with SDS >2 (26%) including three patients having a history of PCI. The proportion of patients with a history of PCI tends to be high with SDS >2 (38% vs 9%, p=0.056).

Conclusion

This modality using 13N ammonia PET is useful for easily detection of CAV before manifestation of symptomatic myocardial ischemia in heart transplant patients.