Serum (1→3) beta-D-glucan (BG) measurement is a useful test for systemic mycoses, and often used. On the other hand, various factors, including administration of intravenous immunoglobulins (IVIG) may cause false-positives. In the present study, we measured BG concentration of seven IVIG preparations with three lots respectively. BG levels varied with individual IVIG preparations (＜3.0 - ＞300pg/mL), and contamination from manufacturing processes was suspected. With serum BG concentration of clinical specimens obtained in Niigata University Medical & Dental Hospital, the difference between before and after administration of IVIG were calculated. The false-positive rate of BG due to IVIG administration was 9.8 %, and the positive predective value was reduced to 37.5%. Above all, administration of IVIG can complicate the BG testʼs interpretation, and caution is required.
Confirmatory tests using Western blot (WB) and HIV-1 nucleic acid testing (HIV-1 RNA) following a positive screening test are required for the diagnosis of HIV-1 infection according to the current Japanese guidelines for HIV-1/2 diagnosis. We report herein on a rare case in a patient who remained negative for WB over 10 months in spite of being positive by fourth-generation immunoassays (4thGIA) and who subsequently seroreverted by 4thGIA for three months after initiating antiretroviral therapy. Case： A man in his early twenties previously visited a hospital because of fever in October 2012. Laboratory data revealed leukocytopenia, thrombocytopenia and increased serum ferritin, suggesting hemophagocytic syndrome (HPS). During that visit, he tested positive for a 4thGIA, but negative for HIV-1 WB and his result of HIV-1 RNA result was detected invalid because of the presence of some inhibitory material in his RNA preparation. Thereafter, he was diagnosed as having cytomegalovirus-associated HPS treatment was for which initiated. In January 2013, he developed Pneumocystis jirovecii pneumonia, and his HIV-1 RNA viral load was 7.7 × 105 copies/mL in February 2013. Acute HIV infection was suspected, because the HIV-1 WB remained negative. He was started on antiretroviral therapy in April 2013. His 4thGIA was converted to negative in May 2013 and was reconverted to positive in August 2013. HIV-1 WB, however, continued to be indeterminant until February 2014, in which it turned positive for the first time according to the CDC criteria. Methods and Results： The genetic analyses of HIV-1 were done on the gag, env, nef and pol region of the HIV-1 gene from the patient. There was no clear element to delay antibody production on the virus side. Preserved specimens of the patient were measured with eight kinds of HIV screening assay. It was thought that the fourth generation assay was positive only by the presence of the antigen until March 2013 because the antibody had not been detected. Discussion：We encountered a case of acute HIV infection in which the WB result was negative for 10 months after the first positive response of the 4thGIA. The 4thGIA is essential for the early diagnosis and early treatment of HIV infection；therefore, the 4thGIA should be strictly recommended to avoid the use of older generations of immunoassay in the diagnostic guidelines. The role of the WB test should be examined closely from various aspects for use as a confirmatory test under recent laboratory situations in which highly sensitive and specific methods, e.g. the 4th GIA, have become available. In addition, unnecessary confusion due to the diversities of antibody formation should be avoided. The antibody detection tests for HIV are still necessary and indispensable for the confirmation of the disease or the diagnosis of the acute infection stage. Therefore development of a newer antibody measuring method which could achieve an easier operation and should have a higher sensitivity and specificity for HIV confirmation is strongly expected.
Carbapenem-resistant Enterobacteriaceae (CRE) are increasing globally. Particularly, carbapenemase producing Enterobacteriaceae (CPE) are of concern. Rapid and accurate detection of these strains is critical for appropriate antimicrobial use and hospital infection control. In the present study, criteria for CPE screening were examined using a carbapenem susceptibility disk. Carbapenemase producers showed minimal inhibition zones for faropenem (5μg)：6-12mm (mean：6.9mm). Some strains with the IMP-6 genotype showed inhibition zones of ＞30 mm for imipenem (10μg) and biapenem (10μg). All strains that formed inhibition zones for FRPM had the IMP-6 genotype. The cut off values of carbapenemase-producers, determined by ROC analysis, were 12 mm for FRPM, 24 mm for meropenem (10μg), 29 mm for BIPM, 25 mm for doripenem (10μg), 26 mm for IPM, and 24 mm for panipenem (10μg). Thus, the sensitivity was the highest (100%) for FRPM. Specificities were 93.44 % for MEPM and DRPM and 85.25 % for FRPM. Consequently, a drug sensitivity test using FRPM (5μg) disks facilitates simple and accurate CPE screening.
A previously healthy 44-year-old male presented with fever, abdominal pain, liver dysfunction and lymphadenopathy. He was diagnosed as having acute cytomegalovirus (CMV) infection with elevated CMV-IgG and IgM, and observed with supportive therapy. He was admitted to our hospital with prolonged fever lasting for a month. Enhanced CT revealed multiple thromboses in the right pulmonary artery and superior mesenteric vein. Follow-up CT after one week revealed new-onset thromboses in the left pulmonary artery and common iliac vein. Screening tests for thrombophilia were negative. His symptoms were improved with anticoagulant therapy with intravenous heparin, followed by oral warfarin. He was discharged on admission day 28 with good condition. Follow-up CT after 6 months revealed complete resolution of the thromboses. Anticoagulant therapy was stopped after 9 months, and he has been well without recurrence. Though vascular thrombosis is a rare complication, we must be alert to the signs and symptoms of thrombosis in patients with acute CMV infection.
An HIV-infected man in his 30s was transferred to our hospital after the discontinuation of antiretroviral therapy (ART) for 4 years. An intraoral tumor was identified, and a biopsy was performed. The diagnosis was Kaposiʼs sarcoma (KS) and disseminated lesions were detected in his respiratory tract and both lungs on computed tomography (CT) and 2-[18F] fluoro-2-deoxy-D-glucose positron-emission tomography (FDG/PET) imaging with increasing standardized uptake volume (SUV：max 7.4). On the 7th day, he was intubated to maintain his airway, then antiretroviral therapy and chemotherapy with pegylated liposomal doxorubicin were immediately initiated. After a period of remission, pulmonary lesions were detected again. We regarded them as a manifestation of immune reconstitution inflammatory syndrome (IRIS) and gave him short term corticosteroids. The lesions were then successfully controlled without additional chemotherapy. This case suggests that early induction of ART and intensive care can result in the survival of patients with KS having serious stenosis of the respiratory tract. Furthermore, this presenting case suggested that the use of corticosteroids could be a candidate to control IRIS even in patients with Kaposiʼs sarcoma.
We treated an extremely rare case of a mycotic aneurysm with infection of an artificial blood vessel by Saccharomyces cerevisiae, which was the first case in Japan. The patient was an 84-year-old woman. Five months before hospitalization, replacement of the ascending aorta was performed for a dissecting aneurysm of the ascending aorta. On regular follow-up examination, she had no symptoms, but accumulation of a liquid was detected around the artificial blood vessel on computed tomography (CT) imaging. She was immediately hospitalized. An emergency operation was performed because of the infected aneurysm, which accompanied infection of the artificial blood vessel. We could not detect any microorganisms in the blood or tissue culture, but we made a diagnosis of S. cerevisiae infection after performing broad-range polymerase chain reaction (PCR), followed by deoxyribonucleic acid (DNA) sequencing analysis. When an infected aneurysm is suspected after imaging analysis, such as CT, in a patient without fever or chest pain and with poor inflammatory reactions, an infected aneurysm caused by a fungus should be considered, even though blood or tissue culture results are negative. It is important to perform histopathological examination using Grocott silver stain and genetic testing (broad-range PCR and DNA sequencing analysis) of the tissue to identify the fungal infection. In the elderly, the number of cases of infection with S. cerevisiae may increase, and these cases may require more attention in the near future.