Linezolid-Induced Pure Red Cell Aplasia: A Case Report

Linezolid (LZD) has been widely used for treating the infections of multidrug-resistant gram-positive organisms. As we know, anemias induced by Linezolid (LZD) are common. However, LZD-induced pure red cell aplasia (PRCA) is very rare. In this paper, we report on a 68-year-old woman with intravascular stent infection who developed PRCA after treatment with LZD. The patient presented to our hospital with a 6-month history of fever after stent implantation for aneurysms in both lower limbs. Bone culture grew methicillin-resistant Staphylococcus hemolyticus (MRSH). She received LZD after developing adverse reactions to initial antibiotics. Although her infective symptoms were improved by LZD, progressive thrombocytopenia was observed 23 days after LZD therapy. Her platelets declined to 66*10⁹/L and hemoglobin level was 10.1 g/dL. Thrombocytopenia recovered 12 days after cessation of LZD. LZD was administered again due to recovered fever. 57 days after LZD administration, her hemoglobin level was 4.1 g/dL and reticulocytes were 0.2%. Bone marrow smear revealed active granulocyte proliferation and markedly decreased erythropoiesis with vacuolar degeneration. 12 days after cessation of LZD, her hemoglobin and reticulocyte levels rose to 9.6 g/dL and 5.1%, respectively. LZD was used for the third time as fever and inflammatory markers progressively increased, but Hb was reduced to 6.7g/dL 15 days after LZD therapy. 12 days after cessation of LZD, the hemoglobin level rose to 11.9 g/dL. In summary, we suggest complete blood count and reticulocyte count should be monitored to detect bone marrow suppression during long-term LZD therapy, especially in patients aged over 58 and/or with pre-existing anemia, chronic infections, and renal insufficiency.

Anti-OJ antibody-positive anti-synthetase syndrome with repeated arthritis, fever, and recurrent liver cancer: a case report

Background

Anti-isoleucyl-transfer RNA synthetase (anti-OJ) autoantibody-positive anti-synthetase syndrome (ASS) is a rare systemic autoimmune disease that manifests as an inflammatory myopathy and interstitial lung disease. We present a case of an anti-OJ antibody-positive ASS, with recurrent joint pain and fever, significantly elevated inflammatory markers, occult myositis but no interstitial pneumonia. This clinical presentation of an anti-OJ antibody-positive ASS has not been reported before.

Case Description

A 75-year-old male, was admitted to our hospital complaining of recurrent joint pain for more than 1 year, recurrent fever for 6 months, and recurrence of joint pain and fever for 1 week. The patient had a history of chronic viral hepatitis B, hepatocellular carcinoma (HCC) surgery 11 years ago, hypertension and type 2 diabetes. In the past year, the patient visited Departments of orthopedics, Infectious Medicine and rheumatology for many times, and has undergone positron emission tomography-computed tomography (PET-CT), bone marrow puncture and other examinations, but the cause was still unknown. On admission, physical examination showed that the temperature was 39.6 ℃, and there was tenderness in multiple joints and muscles, such as the left ankle, the right shoulder, the left wrist, biceps brachii and quadriceps femoris, and so on. The laboratory results showed white blood cell (WBC) count of 30,500/µL (neutrophils: 90.1%), C-reactive protein (CRP): 140.79 mg/dL, Creatine Kinase and creatine kinase-MB were normal. Because of the muscle tenderness, myositis antibody tests were performed and the anti-OJ autoantibody was positive. Asking the medical history in detail, the patient had myasthenia, which was covered up due to prominent joint pain and fever. The patient had no interstitial pneumonia and mechanic’s hand. Recurrent hepatocellular carcinoma was confirmed 1 year after the diagnosis of ASS, and the clinical symptoms were relieved after surgical resection.

Conclusions

We report this rare case of anti-OJ antibody-positive ASS with atypical manifestations to raise awareness of the disease for clinicians. For patients with recurrent unexplained arthritis with fever, we should consider ASS, and myositis antibody tests should be performed if necessary. Patients with a history of tumours should be monitored for tumour recurrence.

Clinical and Microbiological Characteristics of a Community-Acquired Carbapenem-Resistant Escherichia coli ST410 Isolate Harbouring blaNDM-5-Encoding IncX3-Type Plasmid From Blood

Objectives: The aim of this research was to investigate the clinical and microbiological characteristics of a case of community-acquired carbapenem-resistant Escherichia coli isolated from a patient with a bloodstream infection in China.

Methods:Escherichia coli Huamei202001 was recovered from the first blood culture from a patient hospitalised in China. An antimicrobial susceptibility test was performed, and the genome was sequenced on an Illumina HiSeq X 10 platform with a 150-bp paired-end approach. The generated sequence reads were assembled using Unicycler, and the whole genome sequence data were analysed using bioinformatics tools. Moreover, the patient and her main family members obtained a faecal sample screening test for CRE, the positive strain was further isolated and the identification and antimicrobial susceptibility testing was performed.

Results:Escherichia coli Huamei202001 belonged to sequence type 410. In addition, a blaNDM-5-encoding IncX3-type plasmid was responsible for the spreading of carbapenem resistance. Only the patient was detected as having a positive faecal sample screening test for CRE. Strain Fec01 was identified as E. coli, and the antibiotic susceptibility profile was the same as that of E. coli Huamei202001.

Conclusions:Escherichia coli Huamei202001 is defined as community-acquired carbapenem-resistant Enterobacteriaceae. The clone ST410 that harbours the blaNDM-5-encoding IncX3-type plasmid is causing new high-risk clones globally. Thus, infection control measures should be strengthened to curb the dissemination of IncX3.

B-cell antigen marker expression in nasopharyngeal carcinoma

Immunohistochemical analysis was carried out to examine the characteristics of nasopharyngeal carcinoma (NPC) using 38 biopsy cases obtained from southern China. These cases were divided into 3 groups according to their predominant pattern associated with cell and tissue differentiation which is based on World Health Organization (WHO) classification as follows: 6 cases of squamous cell carcinoma (16%), 25 cases of differentiated non-keratinizing carcinoma (66%), 7 cases of undifferentiated carcinoma (18%). All tumor tissues reacted with MB-1, but they did not react with L26 (CD20), 4KB5 (CD45R), MT-1, and leukocyte common antigen (LCA). Keratin and epithelial membrane antigen (EMA) as epithelial markers focally stained NPC tissues in all cases. Carcinoembryonic antigen (CEA)-positive staining was detected in 7 (28%) of the 25 cases of differentiated non-keratinizing carcinoma and in 3 (43%) of the 7 cases of undifferentiated carcinoma; thus, of 38 cases, 10 (26%) were CEA-positive. On the other hand, squamous cell carcinoma cases did not react with CEA. These NPC tissues did not react with S-100 protein, alpha-1-antichymotrypsin (ACT), lysozyme, vimentin, and desmin. Therefore, it is concluded that some cases of NPC are difficult to distinguish from malignant lymphoma. In certain cases, NPC may be distinguished from malignant lymphoma, using immunohistochemical methods for the detection of MB-1, keratin, EMA, and LCA. Specifically, this evidence suggests that MB-1 may be useful as a tumor marker of NPC. Moreover, the CEA reaction to NPC may be related to the cell differentiation.