Acute Kidney Injury: Medical Causes and Pathogenesis.

Acute kidney injury (AKI) is a common clinical syndrome characterized by a sudden decline in or loss of kidney function. AKI is not only associated with substantial morbidity and mortality but also with increased risk of chronic kidney disease (CKD). AKI is classically defined and staged based on serum creatinine concentration and urine output rates. The etiology of AKI is conceptually classified into three general categories: prerenal, intrarenal, and postrenal. Although this classification may be useful for establishing a differential diagnosis, AKI has mostly multifactorial, and pathophysiologic features that can be divided into different categories. Acute tubular necrosis, caused by either ischemia or nephrotoxicity, is common in the setting of AKI. The timely and accurate identification of AKI and a better understanding of the pathophysiological mechanisms that cause kidney dysfunction are essential. In this review, we consider various medical causes of AKI and summarize the most recent updates in the pathogenesis of AKI.

IDIOPATHIC MULTICENTRIC CASTLEMAN DISEASE (IMCD) AS A MANIFESTATION OF POST-COVID-19 INFLAMMATORY SYNDROME

SESSION TITLE: Pulmonary Manifestations of Infections SESSION TYPE: Case Reports PRESENTED ON: 10/17/2022 03:15 pm - 04:15 pm INTRODUCTION: Post-acute COVID-19 inflammatory syndrome is defined as persistent symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms of original infection (1). These can manifest in various ways, but pulmonary, cardiac, and renal complications are the most common (1), with IL-6 thought to be an important mediator (2). We report what we believe to be the first case of Idiopathic Multicentric Castleman's Disease (iMCD) as a manifestation of post-acute COVID-19 inflammatory syndrome. CASE PRESENTATION: A 36-year old male with history of hypertension and childhood asthma (not on current therapy), and recently resolved COVID-19 from 4 weeks prior, is admitted to the hospital with progressive shortness of breath, cough, fevers and significant fatigue. Prior COVID-19 symptoms included fevers, cough, and shortness of breath, which improved after 2 weeks without treatment. Symptoms returned 2 weeks later and worsened. On admission, he was tachycardic to 108 with temp of 37.8C, and otherwise stable vitals. Pertinent labs included WBC 17 (neutrophil predominant), Hgb 11.6, Cr 2.52, Na 126 and albumin 2.7 (normal baselines). SARS-CoV2 PCR was negative. CT chest with PE protocol showed no PE but moderate bilateral pleural effusions and extensive mediastinal lymphadenopathy. 1.2L clear fluid (transudative with lymphocyte predominance) was removed via thoracentesis. Microbiology, flow cytometry and cytology were unremarkable. Renal and mediastinal lymph node biopsies were taken. Lymph node sampling was non-diagnostic x2, but renal biopsy showed acute microangiopathy without thrombi, concerning for acute glomerulonephritis. Serologic vasculitis and CTD workup were entirely negative. He was treated with a course of prednisone and improved, however as outpatient, had recurrence of all these issues. Repeat thoracentesis x3 was unrevealing. He was again admitted and had an excisional inguinal node biopsy, showing findings consistent with hyaline vascular Castleman Disease. Further heme/onc evaluation and discussion showed diagnosis meeting criteria for iMCD. DISCUSSION: Multicentric Castleman's Disease is most often associated with HHV-8 infection in the setting of HIV. If HHV-8 is negative, the disease is termed idiopathic (iMCD). In these cases, disease is mediated predominantly by IL-6, but the direct cause is unknown, though existing theories include non-specific viral infections, malignancy and autoimmune diseases (3). Our patient had no evidence of malignancy or autoimmune phenomena. Thus COVID-19 illness was the most plausible explanation, especially given known IL-6 activity in COVID-19 inflammatory syndromes. CONCLUSIONS: Post-acute COVID-19 inflammatory syndromes are extensive and can affect any organ system. iMCD is another possible manifestation, and must be diagnosed with excisional lymph node biopsy. High index of suspicion should be maintained to make this diagnosis. Reference #1: Nalbandian, Ani et al. "Post-acute COVID-19 syndrome." Nature medicine vol. 27,4 (2021): 601-615. Reference #2: Phetsouphanh, Chansavath et al. "Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection.” Nature immunology vol. 23,2 (2022): 210-216. Reference #3: Dispenzieri, Angela, and David C Fajgenbaum. "Overview of Castleman disease." Blood vol. 135,16 (2020): 1353-1364. DISCLOSURES: No relevant relationships by Kyle Halligan No relevant relationships by Chris Yan

Acute Vision Loss and Conjunctival Hemorrhage as Telltale Symptoms of PIMS-TS.

There is a global concern about children presenting with inflammatory syndrome with variable clinical features during the ongoing COVID-19 pandemic. This paper reports the first pediatric case of bilateral serous retinal detachment and conjunctival hemorrhage as a revealing pattern of the pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Despite the severity of multisystemic involvement, the management with steroids was very successful. Complete remission was obtained within 3 months of acute onset.

POS-657 PAEDIATRIC HAEMODIALYSIS: A FIVE YEAR EXPERIENCE IN A TERTIARY CENTRE

Introduction: Haemodialysis (HD) is a life saving procedure whose benefits cannot be overemphasized. Its use in the paediatric age group is becoming more popular. The indications mainly include acute kidney injury (AKI) from any aetiology and chronic kidney disease (CKD). Paediatric HD is almost unavailable in most parts of Nigeria, and where available, access is limited by cost, consumables and skilled manpower. We present our HD experience over a five year period in a busy paediatric nephrology unit of a tertiary hospital in Nigeria. Methods: A retrospective review of records from June 2016 to June 2021 assessing the indications for dialysis, complications and estimated blood loss. Results: In all, 62 patients had HD in the study period. Age range was 3 to 18 years with a male to female ratio of 1:1.5. There was a linear increase in the number of patients that had HD from 2016 to 2019 ( 9,11,14,16, respectively). The lowest number of patients were seen between 2020 and June 2021. The commonest indication for HD was AKI secondary to sepsis (64.5%). Others include CKD secondary to a primary renal disease, CKD secondary to lupus nephritis, end stage renal disease, AKI secondary to severe malaria, AKI secondary to nephrotic syndrome and AKI secondary to acute glomerulonephritis ( 9.7%, 9.7%, 8.1%, 3.2%, 3.2%, and 1.6% ). Majority of patients with AKI that had HD required less than three sessions and recovered completely. The average estimated blood loss is about 40mls. The commonest complication of HD reported is dialysis dysequilibrum syndrome. Conclusions: Paediatric HD in our centre has greatly contributed in reducing morbidity and mortality especially with AKI. However the reduction in the number of cases from 2020 till June 2021 could be attributed to the ongoing COVID 19 pandemic which has greatly reduced presentation in the hospital. No conflict of interest