Thrombotic and Cardiovascular Events and Treatment Patterns Among Patients Hospitalized with COVID-19 in Japan: An Analysis of a Nationwide Medical Claims Database

Introduction

Limited data are available regarding the prevalence of thrombotic/cardiovascular disease and treatment patterns for patients with coronavirus disease 2019 (COVID-19) in Japan. In this study we describe patients hospitalized for COVID-19 in Japan.

Methods

This retrospective database study analyzed the Japan Medical Data Vision database (416 acute care hospitals) for patients hospitalized for COVID-19 during the identification period from 1 January 1 to 30 September 2020.

Results

Among 9282 eligible patients, 832 (9%) had developed thrombotic disease including myocardial infarction, ischemic stroke, deep vein thromboembolism and pulmonary embolism. Intriguingly, 171(1.8%) had two thrombotic events and 25 (0.3%) had three or four thrombotic events at the same time. The data also showed that arterial thrombotic events accounted for 77% of total thrombotic events. Anticoagulant and/or antiplatelet medication was provided to 3312 patients. Even with antithrombotic medication, 21.2% of patients suffered from thrombotic diseases.

Conclusions

Patients with COVID-19 could experience thrombotic complications in every blood vessel. Further optimization of medication is crucial for preventing thrombotic complications and improving prognosis.

AB1199 COST-EFFECTIVENESS OF EARLY INITIATION OF ABATACEPT ON JAPANESE RHEUMATOID ARTHRITIS PATIENTS BASED ON THE AMPLE STUDY, USING IORRA REAL WORLD DATA

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory disorder leading to disability and reduced quality of life. Effective treatment with biologic disease-modifying antirheumatic drugs (bDMARD) poses a significant economic burden. The abatacept (ABT) versus adalimumab comparison in biologic-naive RA subjects with background methotrexate (AMPLE) trial1was a head-to-head randomized study.

Objectives:

To assess the cost-effectiveness (CE) of early initiation of ABT on Japanese RA patients with data from the IORRA database (ID).2

Methods:

A model based on the AMPLE study was used to estimate the CE of ABT 1stversus ABT 2ndlines in a cohort of 1000 patients based on responses on ACR20/50/70, HAQ-DI, CDAI and SDAI estimated from the real-clinical data of the ID. Unit costs for direct medical costs of adverse events (AEs), proportions of patients with concomitant medications or outpatient/inpatient visits; doses and duration of concomitant medications were taken from the JMDC claims database.3Uncertainty was assessed in sensitivity analyses (SA) where cost parameters were tested on their ±30% levels. Results were compared between subgroups using cut-offs of 65-years of age and 1.5 of HAQ, or 5-years of treatment duration. The study used a Japanese healthcare payers’ perspective over a 2-year time horizon.

Results:

Incremental costs were all in favor of ABT 2ndline with 137 MJPY (1.1 M€, 120 JPY=1 €), 6 MJPY (0.05 M€), 41 MJPY (0.3 M€), 8 MJPY (0.07 M€) and 2.2 MJPY (0.02 M€) for bDMARDs, concomitant medication, AEs, serious AE, and hospitalizations due to infections, respectively. In total, the incremental costs were expected to be 195 MJPY (1.6 M€) higher for ABT as 1stline treatment, but the cost per responding patient and per patient in remission favored ABT 1stline across most response outcomes (Table 1).

Table 1.

Total costs per responder and patient in remission per 2-year

Difference in cost per health gain(ABT first line - ABT second line)Cost per responding patient (kJPY)ACR20-2,927 (-24 k€)ACR50-6,406 (-53 k€)ACR70-10,822 (-90 k€)HAQ-DI-5,120 (-43 k€)Cost per patient in remission (kJPY)DAS28828 (7 k€)CDAI-7,019 (-58 k€)SDAI-5,584 (-47 k€)

ABT=abatacept; ACR20/50/70= 20/50/70% improvement of the American college of rheumatology criteria; HAQ-DI=health assessment questionnaire disability index; DAS28=disease activity score; CDAI=clinical disease activity index; SDAI=simplified disease activity index

SA showed that the cost for bDMARDs drives the difference in healthcare costs between the cohorts (-685 MJPY to 1,074 MJPY). For sub-groups of patients ≥65 years, <65 years, HAQ≥1.5, HAQ <1.5, treatment duration ≥5 years, <5 years the total 2-yearly costs per responder (SDAI remission) were 106 kJPY (0.9 k€), 321 kJPY (2.7 k€), 1,353 kJPY (11.3 k€), 106 kJPY (0.9 k€), 231 kJPY (1.9 k€) and 178 kJPY (1.5 k€) lower for ABT 1stline, respectively.

Conclusion:

Savings per responding patient are expected if ABT are prescribed as 1stline versus 2ndor 3rdline treatment, irrespective of age, disease duration and functional impairment level.

References:

[1]Sokolove J MS et al.,Anna rheum dis.2015;74(Suppl 2)

[2]IORRA cohort database, Tokyo Women’s Medical University, Tokyo, Japan

[3]JMDC claims database, Tokyo, Japan

Disclosure of Interests:

Eiichi Tanaka Consultant of: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Speakers bureau: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: EI has received speaker fee from Bristol-Meyers, Pfizer, Merck serono., Ayako Shoji Consultant of: To conduct this work, Jonas Nilsson Consultant of: To conduct this study, Christos Papagiannopoulos Consultant of: To conduct this study, Dhanda Devender Shareholder of: BMS, Employee of: BMS, Yoshio Anazawa Shareholder of: BMS, Employee of: BMS, Yuri Yoshizawa Shareholder of: BMS, Employee of: BMS, masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma.

Expression of novel molecules, MICAL2-PV (MICAL2 prostate cancer variants), increases with high Gleason score and prostate cancer progression

PURPOSE

The aim of this study is to identify novel molecular targets for development of novel treatment or diagnostic markers of prostate cancer through genome-wide cDNA microarray analysis of prostate cancer cells purified by laser microdissection.

EXPERIMENTAL DESIGN AND RESULTS

Here, we identified molecule interacting with CasL-2 prostate cancer variants (MICAL2-PV), novel splicing variants of MICAL2, showing overexpression in prostate cancer cells. Immunohistochemical analysis using an antibody generated specific to MICAL2-PV revealed that MICAL2-PV was expressed in the cytoplasm of cancer cells with various staining patterns and intensities, whereas it was not or hardly detectable in adjacent normal prostate epithelium or prostatic intraepithelial neoplasia. Interestingly, immunohistochemical analysis of 105 prostate cancer specimens on the tissue microarray indicated that MICAL2-PV expression status was strongly correlated with Gleason scores (P < 0.0001) or tumor classification (P < 0.0001). Furthermore, the expression levels of MICAL2-PVs were also concordant to those of c-Met, a marker of tumor progression, with statistical significance (P = 0.0018). To investigate its potential of molecular therapeutic target for prostate cancers, we knocked down endogenous MICAL2-PVs in prostate cancer cells by small interfering RNA, which resulted in the significant reduction of prostate cancer cell viability.

CONCLUSIONS

Our findings suggest that MICAL2-PV is likely to be involved in cancer progression of prostate cancer and could be a candidate as a novel molecular marker and/or target for treatment of prostate cancers with high Gleason score.

PCOTH, a novel gene overexpressed in prostate cancers, promotes prostate cancer cell growth through phosphorylation of oncoprotein TAF-Ibeta/SET

Through genome-wide cDNA microarray analysis coupled with microdissection of prostate cancer cells, we identified a novel gene, prostate collagen triple helix (PCOTH), showing overexpression in prostate cancer cells and its precursor cells, prostatic intraepithelial neoplasia (PIN). Immunohistochemical analysis using polyclonal anti-PCOTH antibody confirmed elevated expression of PCOTH, a 100-amino-acid protein containing collagen triple-helix repeats, in prostate cancer cells and PINs. Knocking down PCOTH expression by small interfering RNA (siRNA) resulted in drastic attenuation of prostate cancer cell growth, and concordantly, LNCaP derivative cells that were designed to constitutively express exogenous PCOTH showed higher growth rate than LNCaP cells transfected with mock vector, suggesting the growth-promoting effect of PCOTH on prostate cancer cell. To investigate the biological mechanisms of this growth-promoting effect, we applied two-dimensional differential gel electrophoresis (2D-DIGE) to analyze the phospho-protein fractions in LNCaP cells transfected with PCOTH. We found that the phosphorylation level of oncoprotein TAF-Ibeta/SET was significantly elevated in LNCaP cells transfected with PCOTH than control LNCaP cells, and these findings were confirmed by Western blotting and in-gel kinase assay. Furthermore, knockdown of endogenous TAF-Ibeta expression by siRNA also attenuated viability of prostate cancer cells as well. These findings suggest that PCOTH is involved in growth and survival of prostate cancer cells thorough, in parts, the TAF-Ibeta pathway, and that this molecule should be a promising target for development of new therapeutic strategies for prostate cancers.

Identification of STAG1 as a key mediator of a p53-dependent apoptotic pathway

A mutant version of p53 (p53-121F), in which phenylalanine replaces the 121st serine residue, can induce apoptosis more effectively than wild-type p53 (wt-p53). In view of this observation, we considered that one or more apoptosis-related p53-target genes might be preferentially induced by p53-121F. We carried out cDNA microarray analysis to identify such genes, using mRNAs isolated from LS174T colon-cancer cells infected by adenovirus vectors containing either p53-121F (Ad-p53-121F) or wt-p53 (Ad-p53). The STAG1 gene was one of the transcripts showing higher expression levels in cells infected with Ad-p53-121F as opposed to Ad-wtp53. The encoded product appears to contain a transmembrane domain, and binding motifs for SH3 and WW. In two other cancer cell lines, the expression of STAG1 mRNA was induced in response to various genotoxic stresses in a p53-dependent manner; moreover, enforced expression of STAG1 led to apoptosis in several additional cancer cell lines. Suppression of endogenous STAG1 using the RNA-interference method reduced the apoptotic response, whether induced by Ad-p53-121F or Ad-p53. These results suggest that STAG1, a novel transcriptional target for p53, mediates p53-dependent apoptosis, and might be a good candidate for next-generation gene therapy.

Molecular features of the transition from prostatic intraepithelial neoplasia (PIN) to prostate cancer: genome-wide gene-expression profiles of prostate cancers and PINs

To characterize the molecular feature in prostate carcinogenesis and the putative transition from prostatic intraepithelial neoplasia (PIN) to invasive prostate cancer (PC), we analyzed gene-expression profiles of 20 PCs and 10 high-grade PINs with a cDNA microarray representing 23,040 genes. Considering the histological heterogeneity of PCs and the minimal nature of PIN lesions, we applied laser microbeam microdissection to purify populations of PC and PIN cells, and then compared their expression profiles with those of corresponding normal prostatic epithelium also purified by laser microbeam microdissection. A hierarchical clustering analysis separated the PC group from the PIN group, except for three tumors that were morphologically defined as one very-high-grade PIN and two low-grade PCs, suggesting that PINs and PCs share some molecular features and supporting the hypothesis of PIN-to-PC transition. On the basis of this hypothesis, we identified 21 up-regulated genes and 63 down-regulated genes commonly in PINs and PCs compared with normal epithelium, which were considered to be involved in the presumably early stage of prostatic carcinogenesis. They included AMACR, OR51E2, RODH, and SMS. Furthermore, we identified 41 up-regulated genes and 98 down-regulated genes in the transition from PINs to PCs; those altered genes, such as POV1, CDKN2C, EPHA4, APOD, FASN, ITGB2, LAMB2, PLAU, and TIMP1, included elements that are likely to be involved in cell adhesion or the motility of invasive PC cells. The down-regulation of EPHA4 by small interfering RNA in PC cells lead to attenuation of PC cell viability. These data provide clues to the molecular mechanisms underlying prostatic carcinogenesis, and suggest candidate genes the products of which might serve as molecular targets for the prevention and treatment of PC.

Sequence of a cDNA encoding acetylcholinesterase from susceptible and resistant two-spotted spider mite, Tetranychus urticae

Acetylcholinesterase (AChE) from two-spotted spider mites, Tetranychus urticae was compared between an organophosphate susceptible (TKD) and a resistant (NCN) strain. The AChE of TKD had lower affinity to acetylthiocholine and propionylthiocholine than that of NCN, and the inhibition of AChE by DDVP, ambenonium, eserine and n-methyl-eserine showed that NCN was more insensitive than TKD. AChE cDNA sequence was determined, and the 687 amino acids of primary structure were deduced. There were six replacements of amino acid residues in TKD and two in NCN. #F331(439)C was the only substitution unique to NCN, however, this mutation existed homozygously in only two out of nine mites. This residue is one of the gorge lining components, and #F331(439)C might act an important role in the sensitivity of AChE to the inhibitors.

Cyclin K as a direct transcriptional target of the p53 tumor suppressor

Cyclin K, a newly recognized member of the "transcription" cyclin family, may play a dual role by regulating CDK and transcription. Using cDNA microarray technology, we found that cyclin K mRNA was dramatically increased in U373MG, a glioblastoma cell line deficient in wild-type p53, in the presence of exogenous p53. An electrophoretic mobility-shift assay showed that a potential p53-binding site (p53BS) in intron 1 of the cyclin K gene could indeed bind to p53 protein. Moreover, a heterologous reporter assay revealed that the p53BS possessed p53-dependent transcriptional activity. Colony-formation assays indicated that overexpression of cyclin K suppressed growth of T98G, U373MG and SW480 cells. The results suggested that cyclin K may play a role in regulating the cell cycle or apoptosis after being targeted for transcription by p53.

Identification of the interferon regulatory factor 5 gene (IRF-5) as a direct target for p53

Interferon regulatory factors (IRFs) regulate transcription of interferon genes through DNA sequence-specific binding to these targets. Using a differential display method for examining gene expression in p53-defective cells infected with adenovirus containing wild-type p53, we found that expression of interferon regulatory factor 5 (IRF-5) mRNA was increased in the presence of exogenous p53. An electrophoretic mobility-shift assay showed that a potential p53 binding site (p53BS) detected in exon 2 of the IRF-5 gene could in fact bind to p53 protein. Moreover, a heterologous reporter assay revealed that the p53BS possessed p53-dependent transcriptional activity. Expression of IRF-5 was induced in p53+/+ cells (MCF7 and NHDF), but not inp53-/- cells (H1299) when DNA was damaged by gamma-irradiation, UV-radiation, or adriamycin treatment in a wild-type p53-dependent manner. These results suggest that IRF-5 is a novel p53-target, and that it might mediate the p53-dependent immune response.

Radionuclide venography and its functional analysis in superior vena cava syndrome

In addition to imaging, radionuclide venography maybe used for the functional assessment of superior vena cava (SVC) syndrome by applying the indices of transit time (TT), time of half-peak count (TH) and peak count ratio (PC ratio).

METHODS

Ten healthy subjects (Group N) and 107 patients with SVC syndrome (64 symptomatic and 43 asymptomatic) were studied. Images were visually assessed for collaterals or jugular venous reflux and values of the indices were calculated.

RESULTS

The 107 patients were subclassified into three groups according to the images obtained. Collateral circulation was seen in 37 patients (Group C). In 20 patients, jugular venous reflux was observed (Group J). Fifty patients who showed neither collaterals nor reflux were included in Group P. In comparison to Group N [3.6 +/- 0.56 see (sem)], TT values were significantly higher (p < 0.05) for Group J (7.13 +/- 1.16 sec) and Group C (7.00 +/- 0.87 sec). Values of TH were significantly prolonged (p < 0.05) for Group J (23.6 +/- 4.8 sec) and Group C (18.8 +/- 2.2 sec) in comparison to Group N (9.2 +/- 1.5 sec). PC ratio values were higher in all patient groups in comparison to Group N (3.4 +/- 0.57).

CONCLUSION

These indices are potentially useful in the initial diagnosis and post-therapeutic evaluation of SVC syndrome. In the absence of other causes, appearance of jugular venous reflux may be considered a sign of SVC syndrome.

Inhalation of pertechnegas: similar clearance from the lungs to that of inhaled pertechnetate aerosol

It has been reported that the inhalation of pertechnegas (TGO3) generated under an atmosphere of 3% oxygen (O2) in argon (Ar) instead of 100% Ar without O2 in the technegas generator, offers a simple but accurate quantification of clearance from the lungs, permitting it to be used in place of 99Tcm-diethylenetriamine pentaacetic acid (DTPA). The disappearance from the lungs of inhaled TGO3 was so similar to that of inhaled pertechnetate aerosol (TcO4) in this study, that there was neither a statistically significant difference in the clearance half-time (t1/2), nor a difference in the lung images between them. Neither TGO3 nor TcO4 inhalation could distinguish smokers from non-smokers using t1/2. When inhaled, TGO3 appears to behave in a similar manner to TcO4 in the lungs and hence cannot be used in place of 99Tcm-DTPA in clinical practice.

Establishment of a cell line from an adenocarcinoma of the lung producing carcinoembryonic antigen (CEA) and CA19-9

An adenocarcinoma cell line was established from pleural effusion of a 67-year-old woman and designated as TK-SA. The population doubling time of the cells was 100.4 hr. Chromosomal analysis revealed the TK-SA to have human aneuploid chromosomes with a near-triploid mode. Ultrastructurally, the TK-SA was compatible with adenocarcinoma. The cell line was highly tumorigenic. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye assay demonstrated resistance of the cell line to Cis-platin (CDDP), Cyclophosphamide (CPM) and Tegafur/Uracil (UFT). High carcinoembryonic antigen (CEA) and CA19-9 levels were similar in patient's serum and conditioned medium.

Technegas versus krypton-81m gas as an inhalation agent. Comparison of pulmonary distribution at total lung capacity

Exactly how the pulmonary distribution of inhaled radioactive gas and Technegas, or ultra-small aerosol particulates, differs from each other, is still uncertain. The authors compared the distribution of inhaled Kr-81 m gas and Technegas in the lungs at total lung capacity in 13 control subjects with no clinical conditions and 13 patients with various chest diseases. In normal lungs, there was no difference in the distribution ratios in the right and left lungs between inhaled Kr-81m gas and Technegas. However, there was a significant difference in the lungs of patients with pulmonary disease. Technegas tended to deposit more in the lung bases than did Kr-81m gas. Despite these statistical differences, they were visually, or qualitatively, similar. From a practical and clinical standpoint, Technegas seems to be useful as an inhalation agent, unless quantitative analyses are required.

Difference in inhaled aerosol deposition patterns in the lungs due to three different sized aerosols

Deposition patterns of inhaled aerosol in the lungs were studied in five normal subjects and 20 patients with lung disease by inhaling radioaerosols with three different particle size distributions. These aerosols were generated from BARC, UltraVent, and Mistogen-EN-142. Particle size distributions generated by these three nebulizers were 0.84, 1.04 and 1.93 microns in activity median aerodynamic diameter (AMAD) with its geometric standard deviation (sigma g) of 1.73, 1.71 and 1.52, respectively. Deposition patterns of inhaled aerosols were compared qualitatively and quantitatively by studying six different parameters: alveolar deposition ratio (ALDR), Xmax, Xmean, standard deviation (S.D.), skewness and kurtosis of the radioactive distribution in the lungs following inhalation. It has been found that aerosol deposition patterns varied with particle size. The unevenness of aerosol deposition, Xmax, Xmean and the number of 'hot spots' became more prominent with the increase in particle size, whereas values of ALDR and S.D. decreased as particle size increased. Knowing these deposition characteristics would facilitate a judicious application of aerosol inhalation to medical use.

[Changes in pulmonary epithelial permeability due to thoracic irradiation]

The changes in pulmonary epithelial permeability during and following radiation therapy were studied in 10 patients with malignant diseases of the chest; 9 patients with bronchogenic carcinoma and one with thymoma. 99mTc-DTPA aerosol was inhaled during tidal breathing with the patient in supine position, and radioactivity was measured anteriorly by a gamma camera and recorded on a computer. Half time clearance (t1/2) was calculated from exponential fitting of time activity curves by regression analysis in various regions of interest in the initial 7 min following completion of aerosol inhalation. Studies were made every two weeks. In patients who developed radiation pneumonitis, t1/2 values decreased and reached the nadir at the time of manifest pneumonitis, indicating increased pulmonary epithelial permeability. Increased pulmonary epithelial permeability was observed not only in the pneumonic regions but also in the contralateral normal lung regions. Steroid therapy reversed these changes. Increased pulmonary epithelial permeability was observed in 2 out of 5 patients who did not develop radiation pneumonitis. In summary, pulmonary epithelial permeability changes occur not only in regions of radiation pneumonitis but also in non-irradiated lung regions following radiation therapy. We consider that the judicious use of this method enables detection of changes in pulmonary epithelial permeability prior to the development of clinical manifestations of radiation pneumonitis.

A case of pulmonary hyalinizing granuloma

A case of pulmonary hyalinizing granuloma was presented. The patient was a 37-year-old male who was found to have abnormal chest roentgenograms showing multiple pulmonary nodules taken at the annual chest mass survey in October 1989. The largest nodule measured 35 mm in diameter. He was asymptomatic. No definite diagnosis was established either by brushing cytology, biopsy through bronchoscopy or percutaneous needle biopsy. No abnormalities were found in the GI tract, the urogenital system or the bone. Brain CT indicated an iso-density area surrounded by low density in the left fronto-parietal region. Two nodules of the lingula removed by open lung biopsy revealed a homogeneous cut surface. Histological diagnosis was pulmonary hyalinizing granuloma, consisting of hyalinized collagen fibers and bundles infiltrated with chronic inflammatory cells. No therapeutic effect was recognized with prednisolone. Craniotomy was performed and the brain lesion was removed. Anaplastic astrocytoma was the diagnosis. The brain lesion had no etiological correlation with pulmonary hyalinizing granuloma. Pulmonary hyalinizing granuloma itself is a rare benign disease with no specific therapy and is important in the differential diagnosis of lung diseases showing multiple pulmonary nodules.

Effect of respiratory phases and gravity on mucociliary transport in the normal lungs

Effect of gravity and respiratory phase on mucociliary transport was studied in 11 normal subjects. After inhaling 99mTc-human serum albumin aerosol, each subject was positioned in right lateral decubitus and then supine position before a scintillation camera. Data in list mode and simultaneous respiratory curve were stored in a computer for 15 min each. The respiratory curve was sequentially marked at the beginning of inspiration, expiration and pause of each respiratory cycle and list mode data was converted into frame mode, respectively. The frame mode data was then sequentially connected according to the respective respiratory phase. The data in count-per-second from each lungs versus time was fitted to a straight line by regression analysis and the slope of the line was compared with each other for respective respiratory phase. Slopes of net radioactivity changes in the right and left lungs were compared to evaluate gravity effect. Neither respiratory phases nor gravity had any significant effect on mucociliary transport. Theoretical calculations have also supported the present findings.

[Pulmonary epithelial permeability in normal subjects and patients with idiopathic interstitial pneumonia]

99mTc-DTPA is a low molecular weight substance which is believed to pass through the pulmonary epithelium when it is inhaled as an aerosol. We performed 99mTc-DTPA inhalation studies in 10 nonsmoking normal subjects and 10 patients with biopsy proven idiopathic interstitial pneumonia prior to therapy. 99mTc-DTPA aerosol was inhaled for 3 min with the subject in the supine position and radioactivity was measured anteriorly with a gamma camera and recorded on a computer. Measurements were performed for 3 min with the subject inhaling aerosol and for the subsequent 30 min with the subject in the same position. Time activity curves from the five regions of interest (ROIs) including the entire left lung, the entire right lung, and the upper, middle and lower third of the right lung were separately fitted to a single exponential function for the initial 7 min following cessation of inhalation, and the respective clearance half life (t1/2) in min was calculated. Lung function data, arterial blood gas tensions and blood chemistry were also obtained for comparison with the t1/2 values. The t1/2 values were significantly smaller in all ROIs in patients with idiopathic interstitial pneumonia than in normal subjects, indicating a increased pulmonary epithelial permeability in these patients. There was no relationship between t1/2 and %DLco, %DLco/VA, PaO2, or LDH. Although the true pathophysiologic significance of t1/2 measured using 99mTc-DTPA aerosol is still not known, we consider that this measurement may be an important indicator of nonrespiratory lung function, in particular the degree of alveolar epithelial damage.

Incidence of pulmonary embolism in a chest hospital in Japan and importance of preoperative perfusion lung imaging in the diagnosis of postoperative pulmonary embolism

The incidence of pulmonary embolism was retrospectively studied in a University Chest Institute and its affiliated hospital in Sendai, Japan, whose annual numbers of discharged patients from chest medical wards and lung operations as a whole are about 600 and 400, respectively. Before 1975 there was no documented patient with pulmonary embolism. Since then 70 patients had been clinically suspected of having pulmonary embolism and 31 of the 70 were diagnosed as having pulmonary embolism; 15 without and 16 with surgical operations in the immediate past. Fourteen of the 31 patients required combined perfusion and aerosol inhalation lung imaging for diagnosis. Twelve postoperative patients could be diagnosed as pulmonary embolism by comparing postoperative perfusion lung images taken at the time of suspicion with preoperative perfusion counterparts. Although it is said to be rising, the incidence of pulmonary embolism in a chest hospital still seems to remain low compared with that in western countries. For postoperative patients, comparison with preoperative studies was found very useful in diagnosing postoperative pulmonary embolism. The importance of preoperative perfusion lung imaging cannot be overstressed not only as a preoperative lung function test but as a baseline study to be compared with postoperative perfusion images when pulmonary embolism is clinically suspected in postoperative patients.

Technegas for inhalation lung imaging

Technegas, an aerosol generator recently devised in Australia, produces aerosol particulates called 'technegas' which have characteristics of both an aerosol and a gas. The majority of the particulate is below 200 nm in size as measured by electron microscopy. Four normal subjects and 31 patients with various lung diseases were studied by imaging the lungs following inhalation of technegas. The penetration of inhaled technegas to the lung periphery was excellent; the average alveolar deposition ratio (ALDR) was 85%. Comparative studies with lung images obtained either with an ultrasonic nebulizer or jet nebulizers also confirmed better penetration of inhaled technegas to the lung periphery. There was no significant statistical difference in the ALDRs between normals and patients. Aerosol studies were comparable to perfusion counterparts, and evaluation of regional ventilatory status was greatly facilitated. Because of the large ALDR and the low airway deposition ratio (ADR), actual imaging could be done not only immediately after aerosol inhalation but also some time later without losing too much radioactivity from the lungs. One disadvantage was that technegas immediately after generation was anoxic.

[Radioaerosol inhalation lung imaging using technegas]

Technegas generator using 99mTc-pertechnetate was tested on 4 normal subjects and 31 patients with various chest diseases including bronchogenic carcinoma, pneumonia, pulmonary tuberculosis, sarcoidosis, and so on. Technegas was inhaled from the RV to the TLC levels through the mouth with the nose clipped followed by breath-holding. Three deep breaths were enough to deposit 37-55.5 MBq (1 to 1.5 mCi) of technegas in the lungs. The average alveolar deposition ratio (ALDR) was 85% and penetration of inhaled technegas to the lung periphery was excellent. "Hot spots" or excessive radioactive deposition were also seen when there was airway obstruction. The former indicated the characteristic as gas and the latter, that as aerosol particles. Because of the large ALDR's the timing for imaging lungs after inhalation of technegas most likely indicated the intrapulmonary sites of effective ventilation, because respective inhalation and perfusion lung images resembled each other very much. The disadvantage of technegas was that it was anoxic right after generation.

Mucociliary clearance and transport in bronchiectasis: global and regional assessment

Global and regional mucociliary clearance and transport in the lungs was studied in 20 patients with bronchiectasis by radioaerosol inhalation lung cine-scintigraphy and the quantitative analysis following inhalation of ultrasonically-generated 99mTc-tagged human serum albumin aerosol (mass median diameter; 1.93 microns with geometric s.d. of 1.52). In bronchiectatic lung regions, deposition of inhaled aerosol was diminished or inhomogeneous. Transport of inhaled radioactivity from the bronchiectatic regions was deranged in 95% of the patients (19/20). The following abnormal mucous transport patterns were regionally observed; stasis in 12 of the 20 patients (12/20), regurgitation or reversed transport in 14/20, straying in 8/20, spiral or zigzag transport in 1/20, and/or various combinations of these four abnormal transport patterns. When coughs occurred, regurgitation and stray became more marked in the bronchiectatic regions. These regional abnormalities in mucociliary transport seem to be responsible for the development of infections and hemoptysis in the bronchiectatic regions.

Does a beta 2-stimulator really facilitate mucociliary transport in the human lungs in vivo? A study with procaterol

The purpose was to study whether procaterol, a beta 2-stimulator, facilitated mucociliary transport on the ciliated airways in the human lungs. From immediately after inhalation of [99mTc]albumin aerosol, radioactivity of the thorax was continuously measured anteriorly by a gamma camera with the examinee in the supine position; the data were sequentially stored in a computer in 10-s frame mode. Three puffs (30 micrograms) of procaterol were inhaled from a metered dose inhaler at 60 min in the same supine position, and measurement of radioactivity was continued for 30 min more. Spirometry was performed before and after the measurement of radioactivity. A group of 8 normal subjects and 34 patients with various lung diseases, including 6 with bronchial asthma in remission, were studied. In addition to observation of mucus transport on the large airways by radioaerosol inhalation lung cinescintigraphy, the time-activity curve from the right lung was evaluated and the quantitative parameters for evaluating mucociliary clearance were calculated for the right lung. Following inhalation of procaterol, there were neither significant acceleration in mucus transport on the large airways by cinescintigraphy nor significant changes in the slope of time-activity curves. Quantitative parameters did not show any significant changes either, although spirometry indicated significant bronchodilation. We conclude that three puffs of inhaled procaterol neither necessarily accelerate mucus transport nor facilitate mucociliary clearance in the human lung.

Normal values for quantitative parameters for evaluation of mucociliary clearance in lungs

Twenty-eight normal male subjects (13 nonsmokers and 15 smokers, 25 to 76 years of age) inhaled ultrasonically generated 99mTc-tagged human serum albumin aerosol (mass median diameter: 1.93 microns with geometric standard deviation of 1.52) and radioactivity from the thorax was measured continuously from anteriorly in 10 sec frame mode for 90 to 120 min to evaluate mucociliary clearance function in the lungs. Normal values for lung retention ratio (LRR), airway deposition ratio (ADR), airway retention ratio (ARR), airway clearance efficiency (ACE), alveolar deposition ratio (ALDR), and disappearance rate of radioactivity from the ciliated airways (DR) were presented. ALDR was significantly larger in nonsmokers than in smokers. LRR and ARR were significantly smaller and ACE, significantly larger in smokers at any time intervals than in nonsmokers, while ADR and DR were larger in smokers only in the initial 30 min following radioaerosol inhalation was completed. Thereafter there was little difference in ADR and DR between normal smokers and nonsmokers.

Mucociliary clearance in pulmonary vascular disease

The mucociliary clearance function was studied by radioaerosol inhalation lung cinescintigraphy and its quantification in 8 patients with pulmonary vascular diseases; pulmonary embolism, 5 cases, and right pulmonary artery hypoplasia, pulmonary arteriovenous fistulas, aortitis syndrome, 1 case each. The mucociliary clearance function was found to be well maintained in pulmonary vascular diseases unless ventilation was disturbed. There was no difference in the mucociliary clearance function between pulmonary embolism and other pulmonary vascular diseases.

Effect of bronchodilation on the deposition and clearance of radioaerosol in bronchial asthma in remission

Radioaerosol inhalation lung cine-scintigraphy and lung function tests were performed on ten patients with bronchial asthma in remission before and after inhalation of salbutamol following intravenously administered aminophylline. Radioaerosol inhalation lung cine-scintigraphy was very useful in revealing the changes not only in the deposition patterns of inhaled aerosol in the lungs but also in the dynamic transport of mucus on the airways. The bronchodilating effect of the combined treatment was significant; the inhaled aerosol deposited more homogeneously and less centrally in the lungs, the "penetration index" and the alveolar deposition ratio (ALDR) increased from 31 +/- 3 to 49 +/- 7%, and from 29 +/- 2% to 39 +/- 1%, respectively, while the airway deposition ratio (ADR) decreased from 72 +/- 2 to 61 +/- 1% immediately after the treatment. Lung function data including FVC, FEV 1.0, FEV 1.0%, MMF, V50 and Vp significantly improved after the treatment. There was, however, little visual or quantitative improvement in mucociliary clearance after the treatment.