A case of Sjögren's syndrome in which diffuse cystic lung lesions led to an accurate diagnosis.

Key Clinical Message: Even in the absence of other symptoms or other pulmonary manifestations suggesting Sjögren's syndrome (SS), it is necessary to include SS in the differential diagnosis of diffuse cystic lung disease (CLD). Abstract: A case of SS that presented initially with diffuse CLD is reported. This case is considered rare because diffuse pulmonary cysts were observed in the early stage with few symptoms, only cysts were observed without other lung lesions on imaging, cyst formation was histologically considered to be alveolar loss, and airway lesions not observed on imaging were suspected based on lung function testing. The details of this case provide extremely important information to consider for the diagnosis and management of CLD and SS.

Energy Transfer on Cytoskeleton of Red Blood Cell Ghosts and their Efficiency Control by KCl Concentration-induced Cell Shrinkage.

Lipid bilayer membranes such as liposomes have been utilized as platforms for bioinspired artificial photosynthesis. Embedding functional compounds, including chromophores and catalysts, into two-dimensional lipid membranes allows their high local concentration and proximity, resulting in enhanced reactivity compared to that of homogeneous solutions. The control of photoreactions by the physical and chemical properties of membranes, such as fluidity and phase separation, has also been well studied in recent years. In contrast, it remains difficult to control chemical reactions via dynamic membrane deformation. Here, we report on the control of excitation energy transfer using red blood cell ghosts (RBCGs) as scaffolds, relying on their asymmetric lipid membranes and inherent and unique deformability. RBCGs, in which donor and acceptor molecules were chemically conjugated to a two-dimensional cytoskeleton located beneath the inner membrane, exhibited energy transfer, and their efficiency varied depending on the amount and ratio of donor and acceptor modifications, as confirmed by experimental and theoretical analysis. Furthermore, the KCl concentration-induced RBCG shrinkage enhanced the energy transfer efficiency. Our proposed method is expected to facilitate the construction of photoreaction systems that can be controlled via membrane deformation.

Use of Ultrasonographic Shear Wave Measurements to Diagnose Thyroid Metastasis from Breast Carcinoma.

A metastatic thyroid tumor (MTT) arising from breast carcinoma (BC) is rare and sometimes difficult to diagnose. We present a case of MTT from BC; we suspected anaplastic thyroid carcinoma at initial presentation. The patient was a 58-year-old female with a hard nodule in the right anterior neck and a history of breast cancer. Computed tomography indicated tumors on both thyroid lobes, and ultrasonography (US) with shear wave measurement (SWM) showed malignant features. We performed fine needle aspiration cytology (FNAC), the results of which led us to strongly suspect MTT from BC. The surgically resected specimen was evaluated histopathologically, including by immunohistochemistry (IHC), and the diagnosis was confirmed. In addition to FNAC and IHC, SWM is useful to diagnose MTT from BC.

A Case of Lymphomatosis Cerebri Presenting with Rapid Progression of Dementia: A Literature Review.

Lymphomatosis cerebri is an atypical form of primary central nervous system lymphoma (PCNSL), which frequently causes rapid progression of dementia. A 68-year-old woman exhibited rapidly progressing disorientation and a mini-mental state examination score of 9. The fluid-attenuated inversion recovery of a magnetic resonance image (MRI) demonstrated focal areas of high-signal intensity in the right frontal lobe with a small enhancement, which was histologically diagnosed as diffuse large B-cell type lymphoma. The lesion dramatically shrank, and no enhancements were identified on MRI after treatment with high-dose methotrexate (MTX) and whole-brain radiation (WBR). However, her recovery of cognitive function was poor. The patient visited our clinic every 2 months but succumbed to systemic mycotic sepsis 14 months after the biopsy. Autopsy revealed lymphomatosis cerebri in the patient based on a feature of scattered small clusters of lymphoma cells infiltrating into the brain parenchyma in both cerebral hemispheres. Differentiation of lymphomatosis cerebri from other white matter degenerative diseases is usually challenging because lymphomatosis cerebri seldom forms mass lesions. In lymphomatosis cerebri, the lymphoma cells infiltrate into several regions in the brain tissue, including the basal ganglia, brainstem, and corpus callosum, in addition to periventricular and subcortical white matters. The rapid deterioration of cognitive function in the patient suggests a rapid spread of lymphomatosis cerebri, necessitating early histological diagnosis and prompt treatments. If the diagnosis is obtained, administration of high-dose MTX and WBR followed by rituximab and cytarabine can contribute to a longer survival time, based on our literature review.

Anti-spike protein antibody responses to BNT162b2 mRNA vaccine: A single-center survey in a COVID-19 non-epidemic area in Japan.

Background: There are a few reports on antibody responses after a two-dose BNT162b2 vaccination in non-epidemic areas. We evaluated this phenomenon. Methods: A total of 344 healthcare workers were vaccinated, and the serum anti-receptor-binding domain (RBD) antibody concentrations before and after two weeks following the two-dose BNT162b2 vaccination were measured using electro chemiluminescence immunoassay system. Results: Before vaccination, the antibody titers of all participants were less than 0.6 U/mL. After two doses of the BNT162b2 vaccine injection in 342 participants (2 excluded), a high seroconversion rate (99.7%) was observed. The average (±standard deviation) serum anti-RBD antibody titers were 2324 ± 1739 U/mL. Antibody levels in females and males were 2443 ± 1833 U/mL and 1908 ± 1287 U/mL, respectively (p = 0.037). Conclusion: In a non-epidemic area, two BNT162b2 doses induced a satisfactory antibody response, and the antibody concentrations in females were higher than in males.

Bladder metastasis with additional metastases in multiple other organs 4 years after radical nephrectomy for clear cell renal cell carcinoma: a case report and review of the literature.

BACKGROUND: Renal cell carcinoma rarely metastasizes to the bladder, and its biological behavior is not yet fully understood. CASE PRESENTATION: In our case (54-year-old Japanese woman), computed tomography evaluation suggested the presence of a bladder metastasis, associated with additional metastases in the lungs, mediastinal lymph nodes, ribs, and renal bed, 4 years after radical nephrectomy for renal cell carcinoma. The histological findings of the metastatic bladder tumor were consistent with those of clear cell carcinoma. The mediastinal lymph node, rib, and renal bed metastases responded to treatment with an immune checkpoint inhibitor administered for 12 months after surgery for the bladder and lung metastases. In patients with bladder metastasis, absence of metastases in other organs and an interval of more than 1 year after nephrectomy are known to be favorable prognostic factors. Interestingly, in our case, the bladder metastasis was detected more than 1 year after nephrectomy, which was a favorable factor, but there were also metastases in other organs, which was an unfavorable factor. Therefore, we reviewed the literature, including that pertaining to targeted therapy and immune checkpoint inhibitor therapy published in the last two decades, to analyze the clinical significance of the presence of additional metastasis in other organs in renal cell carcinoma (clear cell type, which is the predominant subtype) patients with bladder metastasis. CONCLUSIONS: Patients with bladder metastasis after nephrectomy for renal cell carcinoma also having metastases in other organs may respond to targeted therapy and immune checkpoint inhibitor therapy. This may suggest that the interval to relapse in the bladder after nephrectomy may be a more important prognostic factor than the presence of synchronous metastases in other organs.

Peroral Cholangioscopy-Guided Targeted Biopsy versus Conventional Endoscopic Transpapillary Forceps Biopsy for Biliary Stricture with Suspected Bile Duct Cancer.

BACKGROUND: The recent improvement of peroral cholangioscopy (POCS) maneuverability has enabled the precise, targeted biopsy of bile duct lesions under direct cholangioscopic vision. However, as only small-cup biopsy forceps can pass through the scope channel, the resulting small sample size may limit the pathological diagnosis of biopsy specimens. This study compared the diagnostic abilities of POCS-guided biopsy and conventional fluoroscopy-guided biopsy for bile duct cancer. METHOD: This multicenter, retrospective cohort study included patients exhibiting bile duct stricture with suspected cholangiocarcinoma in whom POCS-guided and fluoroscopy-guided biopsies were performed in the same session. The primary endpoint was the diagnostic sensitivity for malignancy. The size and quality of the biopsy specimens were also compared. RESULT: A total of 59 patients were enrolled. The sensitivity of POCS-guided biopsy was similar to that of fluoroscopy-guided biopsy (54.0% and 64.0%, respectively). However, when the modalities were combined, the sensitivity increased to 80.0%. The mean specimen size from POCS-guided biopsy was significantly smaller than that from fluoroscopy-guided biopsy. The specimen quality using fluoroscopy-guided biopsy was also better than that using POCS-guided biopsy. CONCLUSIONS: The diagnostic sensitivity of POCS-guided biopsy is still insufficient, mainly because of the limited specimen quantity and quality. Therefore, conventional fluoroscopy-guided biopsy would be helpful to improve diagnostic sensitivity.

Clinical Utility of Fine-Needle Aspiration Cytology for Adenoid Cystic Carcinoma of the Trachea with Thyroid Invasion: A Case Report.

BACKGROUND: Adenoid cystic carcinoma of the trachea (ACCT) is a rare cancer; ACCT with thyroid invasion is particularly rare. We first suspected anaplastic thyroid carcinoma (ATC) but diagnosed ACC after performing fine-needle aspiration cytology (FNAC). Tracheal origin was confirmed postoperatively. CASE DESCRIPTION: A 77-year-old woman presented to our hospital with acute inspiratory dyspnea requiring emergency tracheotomy. Physical examination revealed swelling of the right anterior neck and a hard, immobile mass. Computed tomography (CT) and ultrasonography (US) showed tumor extension to the right thyroid lobe and between the first and third tracheal rings, which caused severe stenosis of the lumen. We performed FNAC. Clinical findings were highly suggestive of ACCT with thyroid invasion. She underwent total laryngectomy, cervical esophagectomy, and thyroidectomy with bilateral selective neck dissection at another hospital. The tumor was located in the right posterior wall of the trachea and extended into the right thyroid gland. Pathological examination showed infiltrative carcinomatous proliferation with tubular and cribriform patterns. The tumor was classified as pT4N1. A definite diagnosis was made after histopathological analysis of the surgical specimen confirmed ACCT. The tumor was positive for FABP7, a putative prognostic marker of ACC, and metastasized to the lungs 3 years after surgery. CONCLUSIONS: ACCT with thyroid invasion is an extremely rare malignant neoplasm. FNAC was useful for differentiating ACCT from other diagnoses and enabled appropriate surgical treatment.

Prediction of blood pressure change during surgical incision under opioid analgesia using sympathetic response evoking threshold.

Opioid inhibition of nociceptive stimuli varies in individuals and is difficult to titrate. We have reported the vascular stiffness value (K) as a standard monitor to quantify sympathetic response with high accuracy. On the contrary, among individuals, a considerable variation in the rate of change in K for constant pain has been observed. In this study, we proposed a new index, the minimum stimulus intensity value that evoked the response on K (MECK: Minimum Evoked Current of K), and evaluated its accuracy in predicting sympathetic response to nociceptive stimuli under constant opioid administration. Thirty patients undergoing open surgery under general anesthesia were included. After anesthetic induction, remifentanil was administered at a constant concentration of 2 ng/ml at the effect site followed by tetanus stimulation. MECK was defined as the minimal current needed to produce a change in K. MECK significantly (P < 0.001) correlated with the rate of change of systolic blood pressure during skin incision (ROCBP). Bland-Altman plot analysis using the predicted ROCBP calculated from MECK and the measured ROCBP showed that the prediction equation for ROCBP was highly accurate. This study showed the potential of MECK to predict blood pressure change during surgical incision under opioid analgesia.Clinical trial registration Registry: University hospital medical information network; Registration number: UMIN000041816; Principal investigator's name: Satoshi Kamiya; Date of registration: July 9th, 2019.

Cardiorespiratory synchronisation and systolic blood pressure correlation of peripheral arterial stiffness during endoscopic thoracic sympathectomy.

Muscle sympathetic nerve activity (MSNA) is known as an effective measure to evaluate peripheral sympathetic activity; however, it requires invasive measurement with the microneurography method. In contrast, peripheral arterial stiffness affected by MSNA is a measure that allows non-invasive evaluation of mechanical changes of arterial elasticity. This paper aims to clarify the features of peripheral arterial stiffness to determine whether it inherits MSNA features towards non-invasive evaluation of its activity. To this end, we propose a method to estimate peripheral arterial stiffness [Formula: see text] at a high sampling rate. Power spectral analysis of the estimated [Formula: see text] was then performed on data acquired from 15 patients ([Formula: see text] years) who underwent endoscopic thoracic sympathectomy. We examined whether [Formula: see text] exhibited the features of MSNA where its frequency components synchronise with heart and respiration rates and correlates with the low-frequency component of systolic blood pressure. Regression analysis revealed that the local peak frequency in the range of heartbeat frequency highly correlate with the heart rate ([Formula: see text], [Formula: see text]) where the regression slope was approximately 1 and intercept was approximately 0. Frequency analysis then found spectral peaks of [Formula: see text] approximately 0.2 Hz that correspond to the respiratory cycle. Finally, cross power spectral analysis showed a significant magnitude squared coherence between [Formula: see text] and systolic blood pressure in the frequency band from 0.04 to 0.2 Hz. These results indicate that [Formula: see text] inherits the features observed in MSNA that require invasive measurements, and thus [Formula: see text] can be an effective non-invasive substitution for MSNA measure.

Peripheral arterial stiffness during electrocutaneous stimulation is positively correlated with pain-related brain activity and subjective pain intensity: an fMRI study.

Brain activity associated with pain perception has been revealed by numerous PET and fMRI studies over the past few decades. These findings helped to establish the concept of the pain matrix, which is the distributed brain networks that demonstrate pain-specific cortical activities. We previously found that peripheral arterial stiffness [Formula: see text] responds to pain intensity, which is estimated from electrocardiography, continuous sphygmomanometer, and photo-plethysmography. However, it remains unclear whether and to what extent [Formula: see text] aligns with pain matrix brain activity. In this fMRI study, 22 participants received different intensities of pain stimuli. We identified brain regions in which the blood oxygen level-dependent signal covaried with [Formula: see text] using parametric modulation analysis. Among the identified brain regions, the lateral and medial prefrontal cortex and ventral and dorsal anterior cingulate cortex were consistent with the pain matrix. We found moderate correlations between the average activities in these regions and [Formula: see text] (r = 0.47, p < 0.001). [Formula: see text] was also significantly correlated with self-reported pain intensity (r = 0.44, p < 0.001) and applied pain intensity (r = 0.43, p < 0.001). Our results indicate that [Formula: see text] is positively correlated with pain-related brain activity and subjective pain intensity. This study may thus represent a basis for adopting peripheral arterial stiffness as an objective pain evaluation metric.

Cerebellar high-grade glioma with H3 K27M mutation: illustrative case.

BACKGROUND: Diffuse midline glioma H3 K27M-mutant is a distinct subtype of glial tumors newly introduced in the revised fourth edition of the World Health Organization Classification of Tumours of the Central Nervous System. They are aggressive pediatric tumors with a poor prognosis but have also been reported in adults. OBSERVATIONS: The authors present the case of a man in his 60s who presented with rotatory vertigo, taste disorder, and right facial paralysis. Magnetic resonance imaging showed a tumor expanding from the cerebellum to the pons, which was histologically identified as glioblastoma, grade IV, IDH wild type. After tumor resection, the patient received chemoradiotherapy but showed only a partial response. His condition gradually worsened, and he died of progressive disease 12 months postoperation, after which an autopsy was performed. Tumor cells with a high nuclear-to-cytoplasm ratio were immunohistochemically analyzed and found to test positive for H3 K27M and negative for H3 K27me3. Furthermore, mutational analysis revealed HIST1H3B K27M mutation, and the tumor was finally identified as a high-grade glioma H3 K27M-mutant. The tumor invaded widely along the cerebral ventricle and disseminated to the spinal cord. LESSONS: When a glioblastoma shows localization or dissemination patterns different from those of typical glioblastoma, an H3 K27M-mutant glioma should be suspected.

A retrospective study of 323 total laparoscopic hysterectomy cases for various indications and a case report treating caesarean scar pregnancy.

BACKGROUND: The application of laparoscopic surgeries has been increasing, and various uterine diseases in addition to leiomyoma/adenomyoma have become indications for total laparoscopic hysterectomy (TLH). Therefore, data acquisition and analysis of TLH procedures, including TLH for rare uterine diseases, have become important for improving surgical procedures and patient selection. To determine the prevalence of and risk factors for the occurrence of intraoperative and postoperative complications of TLH, we performed a multivariate analysis of the records in our hospital. METHODS: We retrospectively reviewed the medical records of 323 patients who underwent TLH for the treatment of leiomyoma/adenomyoma (278 cases), low-grade (pre)malignant uterine tumours (40 cases) and other rare uterine diseases (5 cases) from January 1, 2015, to December 31, 2019. Of the rare uterine diseases, one case of caesarean scar pregnancy for which TLH was performed is introduced as a case report. To assess the effects of 11 representative factors, including patient characteristics, uterus and leiomyoma sizes, indications for TLH and others, we performed a multivariate logistic regression analysis. RESULTS: Among the 323 cases, 20 intraoperative complications and 15 postoperative complications were reported. In the multivariate analysis, "ovarian tumour" and "heavy uterus" were positively associated and "nulliparity" was negatively associated with intraoperative complications. There were no significant risk factors for postoperative complications. The only risk factor for operative complications directly related to the resected uterus was "heavy uterus". Therefore, we could perform TLH relatively safely for patients with other indications besides leiomyoma/adenomyoma. CONCLUSIONS: Considering the factors detected in this analysis, the indications for TLH may be expanded. Owing to the increase in TLH for indications other than leiomyoma/adenomyoma, a more accurate determination of the treatment approach can be achieved.

Retraction Note to: Functional analysis of newly identified RYR1 variants in patients susceptible to malignant hyperthermia.

The authors have retracted this article because they did not have permission to use the data in Tables 1 and 2.

SMARCA4-deficient lung tumour that presented with haemoptysis and progressed rapidly.

The case of a heavy ex-smoking man in his early 70s who presented with haemoptysis and died following rapid progression is presented. The tumour excised by surgery was mostly composed of monotonous large rhabdoid cells showing prominent nucleoli and eosinophilic cytoplasm. On immunohistochemistry with SMARCA4 (BRG-1), the tumour cells showed significant loss of expression. The tumour was diagnosed as a SMARCA4-deficient thoracic sarcoma. This is a disease that progresses rapidly and has a poor prognosis. However, the search for specific treatments using synthetic lethality is underway. Clinical and pathological characteristics can be identified with examination of more cases, and when the tumour is suspected, it is necessary to actively perform immunohistochemical examination.

Propofol induces the elevation of intracellular calcium via morphological changes in intracellular organelles, including the endoplasmic reticulum and mitochondria.

Propofol, most frequently used as a general anesthetic due to its versatility and short-acting characteristics, is thought to exert its anesthetic actions via GABAA receptors; however, the precise mechanisms of its adverse action including angialgia remain unclear. We examined the propofol-induced elevation of intracellular calcium and morphological changes in intracellular organelles using SHSY-5Y neuroblastoma cells, COS-7 cells, HEK293 cells, and HUVECs loaded with fluorescent dyes for live imaging. Although propofol (>50 µM) increased intracellular calcium in a dose-dependent manner in these cells, it was not influenced by the elimination of extracellular calcium. The calcium elevation was abolished when intracellular or intraendoplasmic reticulum (ER) calcium was depleted by BAPTA-AM or thapsigargin, respectively, suggesting that calcium was mobilized from the ER. Studies using U-73122, xestospongin C, and dantrolene revealed that propofol-induced calcium elevation was not mediated by G-protein coupled receptors, IP3 receptors, or ryanodine receptors. We performed live imaging of the ER, mitochondria and Golgi apparatus during propofol stimulation using fluorescent dyes. Concomitant with the calcium elevation, the structure of the ER and mitochondria was fragmented and aggregated, and these changes were not reversed during the observation period, suggesting that propofol-induced calcium elevation occurs due to calcium leakage from these organelles. Although the concentration of propofol used in this experiment was greater than that used clinically (30 µM), it is possible that the concentration exceeds 30 µM at the site where propofol is injected, leading the idea that these phenomena might relate to the various propofol-induced adverse effects including angialgia.

Recurrent probabilistic neural network-based short-term prediction for acute hypotension and ventricular fibrillation.

In this paper, we propose a novel method for predicting acute clinical deterioration triggered by hypotension, ventricular fibrillation, and an undiagnosed multiple disease condition using biological signals, such as heart rate, RR interval, and blood pressure. Efforts trying to predict such acute clinical deterioration events have received much attention from researchers lately, but most of them are targeted to a single symptom. The distinctive feature of the proposed method is that the occurrence of the event is manifested as a probability by applying a recurrent probabilistic neural network, which is embedded with a hidden Markov model and a Gaussian mixture model. Additionally, its machine learning scheme allows it to learn from the sample data and apply it to a wide range of symptoms. The performance of the proposed method was tested using a dataset provided by Physionet and the University of Tokyo Hospital. The results show that the proposed method has a prediction accuracy of 92.5% for patients with acute hypotension and can predict the occurrence of ventricular fibrillation 5 min before it occurs with an accuracy of 82.5%. In addition, a multiple disease condition can be predicted 7 min before they occur, with an accuracy of over 90%.

Functional analysis of newly identified RYR1 variants in patients susceptible to malignant hyperthermia.

PURPOSE: This study aimed to evaluate whether the three ryanodine receptor type 1 (RYR1) variants (p.Ser2345Thr, p.Ser2345Arg, and p.Lys3367Arg) which we identified in Japanese malignant hyperthermia (MH) patients with a clinical grading scale rank of 6 were causative for MH. METHODS: We prepared human embryonic kidney (HEK)-293 cells transfected with wild-type RYR1 or one of the RYR1 variants, along with myotubes cultured from muscle pieces. Calcium kinetics were examined by calculating the 340/380-nm ratio under various caffeine and 4-chloro-m-cresol (4CmC) concentrations with the ratiometric dye Fura-2 AM. Half-maximal effective concentration (EC50) values were calculated from dose-response curves. Statistical analysis was based on one-way analysis of variance with a Dunnett's multiple comparison test, using a P value < 0.05 as evidence of statistical significance. RESULTS: In functional analysis using HEK-293 cells, we found significant reductions in the EC50 of p.Ser2345Thr and p.Ser2345Arg in comparison with wild-type RYR1 (P < 0.001), while the EC50 of p.Lys3367Arg was not significantly different (P = 0.062 for caffeine and P > 0.999 for 4CmC). On the other hand, functional analysis using myotubes showed significant differences in the EC50 values for all variants (P < 0.001 for all comparisons). CONCLUSIONS: p.Ser2345Thr and p.Ser2345Arg appear capable of causing a calcium metabolism disorder that leads to the onset of MH, and p.Ser2345Arg can be considered as a diagnostic mutation, because it meets the European Malignant Hyperthermia Group criteria. However, patients with p.Lys3367Arg might have mutations in genes other than RYR1 that are capable of causing MH.

Unconstrained Vital Sign Monitoring System Using an Aortic Pulse Wave Sensor.

This paper proposes a novel unconstrained monitoring system that measures heart and respiratory rates and evaluates autonomic nervous activity based on heart rate variability. The proposed system measures the aortic pulse waves (APWs) of a patient via an APW sensor that comprises a single microphone integrated into a mattress. Vital signs (i.e., heart rate, respiratory rate) and autonomic nervous activity were analyzed using the measured APWs. In an experiment with supine and seated participants, vital signs calculated by the proposed system were compared with vital signs measured with commercial devices, and we obtained the correlations of r > 0.8 for the heart rates, r > 0.7 for the respiratory rates, and r > 0.8 for the heart rate variability indices. These results indicate that the proposed system can produce accurate vital sign measurements. In addition, we performed the experiment of image stimulus presentation and explored the relationships between the self-reported psychological states evoked by the stimulus and the measured vital signs. The results indicated that vital signs reflect psychological states. In conclusion, the proposed system demonstrated its ability to monitor health conditions by actions as simple as sitting or lying on the APW sensor.

TAFRO syndrome as a cause of glomerular microangiopathy: a case report and literature review.

BACKGROUND: TAFRO syndrome is a systemic inflammatory disorder that manifests as thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O). Renal dysfunction is frequently complicated with TAFRO syndrome, however, it is challenging to perform kidney biopsy in patients with TAFRO syndrome in the presence of thrombocytopenia. Renal histology in TAFRO syndrome mainly shows membranoproliferative glomerulonephritis (MPGN)-like lesions or thrombotic microangiopathy (TMA)-like glomerulopathy. We review our case and previous reports of TAFRO syndrome with kidney biopsy findings and discuss the renal pathophysiology of TAFRO syndrome. CASE PRESENTATION: We describe a previously healthy 48- year-old woman with TAFRO syndrome. Kidney biopsy performed before the treatment showed diffuse global endocapillary proliferative changes with endothelial cell swelling, double contours of partial capillary walls, and mesangiolysis, consistent with TMA-like glomerulopathy. Glucocorticoid therapy including steroid pulse was ineffective and she developed anasarca, renal dysfunction and oliguria. Hemodialysis was required. However, the anti-Interleukin (IL)-6 receptor antibody (tocilizumab) therapy was very effective. An increase in urinary volume was achieved about 2 weeks after the tocilizumab therapy and hemodialysis was discontinued. To investigate the renal pathophysiology of TAFRO syndrome, we performed immunohistological staining of vascular endothelial growth factor (VEGF)-A, CD34, and D2-40, in our case and a normal control kidney. Glomerular VEGF-A was especially positive in podocytes both, in the control and in the case, with no significant difference and there was a significant increase of VEGF-A staining area in the cortical peritubular capillaries in the case. Both glomerular and renal cortical CD34 expression were significantly decreased in our case. D2-40 expression in cortex was not significantly different. CONCLUSIONS: We reviewed our case and other 10 previous reports about renal biopsy findings in TAFRO syndrome and found that glomerular microangiopathy was a common finding. IL-6-VEGF-axis-induced glomerular microangiopathy may play a crucial role in developing acute kidney injury in TAFRO syndrome and the anti-IL-6 receptor antibody therapy may be useful for TAFRO syndrome refractory to glucocorticoids. About the pathophysiology of VEGF in TAFRO syndrome, VEGF balance in the glomerulus and perhaps in the peritubular capillary system as well may be critical. Further investigation is needed.