RA-PCP differed considerably from AIDS-PCP clinically and radiologically. Clinically it occurred without severe immunosuppression, and showed characteristic aspects, with more intense inflammation and less parasite burden. Radiologically it mimicked MTX-P in some cases sharing the conspicuous CT features of MTX-P, rendering the distinction of these two disorders difficult.

Medical records, for 2000 and 2001, of symptomatic amoebic patients who were treated at our hospitals in Tokyo, Yokohama and Osaka were studied retrospectively for the purpose of gathering epidemiological data on symptomatic Entamoeba histolytica infection. A total of 58 patients were treated. Fifty-five of them were male, and 96% of the male patients were Japanese. The mean age of patients was 44.9 years old, and 91% of patients contracted the disease in Japan. Fifty-six per cent of the male patients indicated that they were practising homosexuals, and 44% of the male patients denied these practices or left the question unanswered. The serum Treponema pallidum haemagglutination test was positive in 45% of the patients, and antibody to human immunodeficiency virus (HIV) was positive in 45%. Our study revealed that recent symptomatic E. histolytica infection almost exclusively afflicted middle-aged males in the big cities of Japan, that a majority of the patients were probably exposed to the causative organism during homosexual activity, and that an increasing number of patients will be co-infected with HIV.

To describe the clinical features of dengue cases in Japan, a retrospective study was conducted on 62 laboratory-confirmed Japanese dengue cases presented to Tokyo Metropolitan Komagome Hospital between 1985 and 2000. Age distribution was from 18 to 62 years old (mean, 31.5 years). All cases were imported from abroad and diagnosed as dengue fever. Clinical manifestations included fever (100%), headache (90%), and skin rash (82%). Laboratory examinations revealed leukocytopenia (71%), thrombocytopenia (57%), elevated levels of serum aspartate aminotransferase (78%), and lactate dehydrogenase (71%). Antibody responses were consistent with that of secondary flavivirus infection in 60% of cases. Severity of symptoms in patients with primary dengue antibody response and those with secondary flavivirus antibody responses didn't show statistical significance. Dengue virus infection should be taken into consideration in the differential diagnosis of febrile patients who recently entered Japan from tropical or subtropical countries.

Atazanavir is commonly used as one of the key drugs in combination antiretroviral therapy for human immunodeficiency virus (HIV). However, atazanavir has the potential to yield its crystalline precipitation in urine and renal interstitial tissues, leading to crystalluria, urolithiasis, acute kidney injury (AKI) or chronic kidney disease (CKD). In epidemiological studies, atazanavir/ritonavir alone or in combination with tenofovir has been associated with increased risk of progression to CKD. However, renal biopsies were not provided in these studies. Case reports showing an association between atazanavir use and tubulointerstitial nephritis among HIV-infected individuals provide clues as to the potential causes of atazanavir nephrotoxicity. We now review atazanavir-related kidney disease including urolithiasis, renal dysfunction and interstitial nephritis and illustrate the review with a further case of atazanavir-associated kidney injury with sequential renal biopsies. There are two forms of atazanavir-associated tubulointerstitial nephritis: acute tubulointerstitial nephritis that may develop AKI rapidly (in weeks) after initiation of atazanavir, and chronic tubulointerstitial nephritis that may develop progressive CKD slowly (in years) with granuloma and intrarenal precipitation of atazanavir crystals as well as crystalluria. Caution should be exercised when prescribing atazanavir to patients at high risk of CKD, and therapy should be reevaluated if renal function deteriorates, especially associated with crystalluria and hematuria.

Background Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an international outbreak of coronavirus disease 2019 (COVID-19), data on the clinical characteristics of COVID-19 patients with cancer are limited. This study aimed to evaluate the clinical characteristics and outcomes including mortality and viral shedding period in COVID-19 patients with cancer in Japan. Methods We retrospectively analyzed 32 patients with a history of cancer who were referred to our hospital between January 31, 2020 and May 25, 2020. We evaluated the association between clinical outcomes and potential prognostic factors using univariate analyses. Results The median age was 74.5 (range 24-90) years and 22 patients (69%) were men. A total of 11 patients (34%) died. Our analyses demonstrated that the mortality was significantly associated with lymphocyte count, albumin, lactate dehydrogenase, serum ferritin, and C-reactive protein on admission. The median period between illness onset and the first effective negative SARS-CoV-2 PCR result was 22 days (interquartile range 18-25) in survivors. Of four patients with hematological malignancy who developed COVID-19 within the rest period of chemotherapy, three died and the other patient, who received bendamustine plus rituximab therapy, had the longest duration of viral shedding (56 days). Conclusion Our study suggested that the risk factors for mortality previously reported in general COVID-19 patients, including lymphocytopenia, were also effective in cancer patients. Patients who received cytotoxic chemotherapy recently or were treated with chemotherapy, which can lead to lymphocyte reduction, had poor prognosis and prolonged periods of viral shedding.