Acute kidney injury as a rare manifestation of pediatric sarcoidosis: A case report and systematic literature review

Characteristics and clinical outcomes of patients with sarcoidosis admitted for ST-elevation myocardial infarction in the United States: a propensity matched analysis from the National Inpatient Sample

Introduction

Sarcoidosis is a systemic inflammatory disorder characterised by non-caseating granulomas. Cardiac sarcoidosis (CS) normally causes conduction abnormalities, ventricular arrhythmias, and heart failure. Little is known about the characteristics and impact of sarcoidosis in patients admitted with ST-elevation myocardial infarction (STEMI). This study aims to fill this void.

Material and methods

Utilising the National Inpatient Sample (NIS) database (2016-2020), individuals with STEMI were identified and categorised based on sarcoidosis presence whilst adjusting for confounders via logistic regression models.

Results

Among 851,290 STEMI patients, 1215 had sarcoidosis. Before propensity matching, sarcoidosis patients were notably different in demographics and comorbidities compared to non-sarcoidosis patients. After propensity score matching (PSM), sarcoidosis patients were found to have a higher incidence of supraventricular tachycardia (SVT) (2.5% vs. 1.3%, p = 0.024) and acute kidney injury (AKI) (23.3% vs. 20.8%, aOR = 1.269, 95% CI: 1.02-1.58, p = 0.033) but a lower incidence of undergoing coronary artery bypass graft (CABG) (5.5% vs. 8.5%, aOR = 0.663; 95% CI: 0.472-0.931, p = 0.018), while no significant disparities were noted in PCI, cardiogenic shock, mortality, or mean length of stay (LOS).

Conclusions

Using propensity-matched large real-world data of STEMI patients, sarcoidosis was associated with fewer cases of CABG and a greater incidence of AKI and SVT compared to non-sarcoidosis patients.

The Overlap of Kidney Failure in Extrapulmonary Sarcoidosis in Children-Case Report and Review of Literature

Sarcoidosis is a non-necrotizing granulomatous inflammatory multisystemic disorder of unknown etiology. In children, as in adults, it can involve a few or all organ systems to a varying extent and degree, entailing multisystemic manifestations. Kidney involvement in pediatric-onset adult-type sarcoidosis is rare, with a wide range of renal manifestations, most of them related to calcium metabolism. Children with renal sarcoidosis tend to be more symptomatic than adults, although male patients have a higher prevalence. We present the case of a 10-year-old boy who presented with advanced renal failure with nephrocalcinosis and important hepatosplenomegaly. The diagnosis was established by histopathological examination, with consequent cortisone therapy and hemodialysis. This review emphasizes that sarcoidosis should be considered in the differential diagnosis of pediatric patients with acute kidney insufficiency or chronic kidney disease of an unknown etiology. As far as we know, this is the first study regarding extrapulmonary sarcoidosis in children from Romania.

Renal sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology. The pathogenesis rests on an aberrant T cell response to unidentified antigens in individuals predisposed by genetic and environmental factors. Increased expression of polarized macrophages and disequilibrium between effector and regulator T cells contribute to the formation of noncaseating granulomas, that are frequently found in affected organs. The main kidney abnormalities in sarcoidosis are granulomatous interstitial nephritis (GIN) and hypercalcemia-related disorders. The clinical diagnosis is difficult. The outcome is variable, ranging from spontaneous remission to end-stage kidney disease (ESKD). Early diagnosis and prompt treatment with corticosteroids can improve the prognosis. Hypercalcemia may be responsible for acute kidney injury (AKI) caused by vasoconstriction of afferent arterioles. Complications of persistent hypercalcemia include nephrocalcinosis and renal stones. In patients with ESKD, dialysis and transplantation can offer results comparable to those observed in patients with other causes of kidney failure. Based on a review of the literature, we present an overview of the etiopathogenesis, the renal manifestations of sarcoidosis and their complications, management and prognosis.

Case Report: Pediatric Renal Sarcoidosis and Prognostic Factors in Reviewed Cases

Background: Pediatric sarcoidosis is a complex inflammatory disorder with multisystemic manifestations. Kidney involvement in children is rare, and prognostic factors are unknown. Case Report and Methods: We report the case of a 16-year-old girl with multiorgan sarcoidosis and renal involvement. The patient presented with tubulointerstitial nephritis, acute kidney injury (AKI), chest CT disseminated noduli, granulomatous iridocyclitis, giant-cell sialadenitis, and arthralgia. The kidney biopsy revealed non-granulomatous interstitial nephritis. Treatment consisted of initial high-dose methylprednisolone pulse followed by oral prednisolone and methotrexate. Full remission was achieved. In addition, we performed a literature review using PubMed and analyzed data on pediatric renal sarcoidosis cases. Results: We identified 36 cases of pediatric sarcoidosis with renal involvement on presentation and data on the end-of-follow-up glomerular filtration rate (GFR). The data from the literature review showed that renal involvement was slightly more prevalent in males (60%). AKI was present in most of the described patients (84%). Oral prednisolone was used in 35 of 36 cases; in more severe cases, other immunosuppressants were used. We newly identified renal concentration impairment and granulomatous interstitial nephritis as factors with a clear trend toward GFR loss at the end of follow-up, emphasizing the importance of kidney biopsy in symptomatic patients. In contrast, higher GFR at presentation and hypercalcemia were rather favorable factors. According to the identified predictive factors, our patient has a good prognosis and is in remission. Conclusion: The factors indicating a trend toward an unfavorable renal outcome in pediatric sarcoidosis are renal concentration impairment and granulomatous interstitial nephritis at presentation, while a higher GFR is beneficial.