Symptomatic hyponatremia induced by low-dose cyclophosphamide in patient with systemic lupus erythematosus: A case report

Position statement of the Brazilian society of Rheumatology on mesna use as a preventive therapy for bladder disease in patients with systemic autoimmune diseases and systemic vasculitis under cyclophosphamide treatment

OBJECTIVE

To review current literature to support the use of mesna as a preventive therapy for hemorrhagic cystitis and bladder cancer in patients with systemic autoimmune diseases and systemic vasculitis treated with cyclophosphamide.

MATERIALS AND METHODS

The search for articles was conducted systematically through MEDLINE, LILACS, Cochrane Library, and Embase databases. Only articles in English were selected. For available records, titles and abstracts were selected independently by two investigators.

RESULTS

Eighteen studies were selected for analysis. The known adverse effects of cyclophosphamide were hematological toxicity, infections, gonadal toxicity, teratogenicity, increased risk for malignancy and hemorrhagic cystitis. Long-term toxicity was highly dependent on cyclophosphamide cumulative dose. The risk of bladder cancer is especially higher in long-term exposure and with cumulative doses above 36 g. The risk remains high for years after drug discontinuation. Hemorrhagic cystitis is highly correlated with cumulative dose and its incidence ranges between 12 and 41%, but it seems to be lower with new regimens with reduced cyclophosphamide dose. No randomized controlled trials were found to analyze the use of mesna in systemic autoimmune rheumatic diseases and systemic vasculitis. Retrospective studies yielded conflicting results. Uncontrolled prospective studies with positive results were considered at high risk of bias. No evidence was found to support the use of mesna during the treatment with cyclophosphamide for autoimmune diseases or systemic vasculitis to prevent hemorrhagic cystitis and bladder cancer. In the scenarios of high cumulative cyclophosphamide dose (i.e., > 30 g), patients with restricted fluid intake, neurogenic bladder, therapy with oral anticoagulants, and chronic kidney disease, mesna could be considered.

CONCLUSION

The current evidence was found to be insufficient to support the routine use of mesna for the prophylaxis of hemorrhagic cystitis and bladder cancer in patients being treated for systemic autoimmune diseases and systemic vasculitis with cyclophosphamide. The use may be considered for selected cases.

Machine learning: Predicting hospital length of stay in patients admitted for lupus flares

BACKGROUND

Although rare, severe systemic lupus erythematosus (SLE) flares requiring hospitalization account for most of the direct costs of SLE care. New machine learning (ML) methods may optimize lupus care by predicting which patients will have a prolonged hospital length of stay (LOS). Our study uses a machine learning approach to predict the LOS in patients admitted for lupus flares and assesses which features prolong LOS.

METHODS

Our study sampled 5831 patients admitted for lupus flares from the National Inpatient Sample Database 2016-2018 and collected 90 demographics and comorbidity features. Four machine learning (ML) models were built (XGBoost, Linear Support Vector Machines, K Nearest Neighbors, and Logistic Regression) to predict LOS, and their performance was evaluated using multiple metrics, including accuracy, receiver operator area under the curve (ROC-AUC), precision-recall area under the curve (PR- AUC), and F1-score. Using the highest-performing model (XGBoost), we assessed the feature importance of our input features using Shapley value explanations (SHAP) to rank their impact on LOS.

RESULTS

Our XGB model performed the best with a ROC-AUC of 0.87, PR-AUC of 0.61, an F1 score of 0.56, and an accuracy of 95%. The features with the most significant impact on the model were "the need for a central line," "acute dialysis," and "acute renal failure." Other top features include those related to renal and infectious comorbidities.

CONCLUSION

Our results were consistent with the established literature and showed promise in ML over traditional methods of predictive analyses, even with rare rheumatic events such as lupus flare hospitalizations.

Low-Dose Cyclophosphamide Associated With Hyponatremia and Hepatotoxicity

Cyclophosphamide (CY) is an alkylating agent often used as a chemotherapeutic agent, with increasing use as an immunosuppressant. Cyclophosphamide has many established adverse effects, including hyponatremia and limited reports of hepatotoxicity, particularly in high-dose treatment. A case of simultaneous hyponatremia and acute liver injury associated with the initiation of cyclophosphamide two weeks prior is discussed here. A 73-year-old male with acquired hemophilia A/factor VIII deficiency presented to the emergency department (ED) with four days of hip pain and was found to have jaundice and confusion. Laboratory evaluation demonstrated hyponatremia and an acute liver injury associated with his recent cyclophosphamide use. With the discontinuation of the offending agent and sodium correction, he made a full recovery. Cyclophosphamide-induced hyponatremia is likely secondary to the nephrogenic syndrome of inappropriate antidiuresis (NSIAD) and is most often associated with high-dose regimens. While the mechanism of hepatotoxicity requires further study, it is likely dose-dependent and related to excess levels of 4-hydroxycyclophosphamide (HCY). The management of cyclophosphamide-induced water toxicity and hepatotoxicity is centered around the discontinuation of medication, the correction of electrolyte abnormalities, and supportive treatment.

[Nephrological management and drug dosing in patients with rheumatic diseases and renal insufficiency]

BACKGROUND

In patients with inflammatory rheumatic diseases and renal insufficiency there are two challenges for physicians: to adapt the antirheumatic medication to the renal function and to carry out a nephroprotective treatment that prevents long-term deterioration of renal function and reduces the elevated cardiovascular risk.

METHODS

A literature search (in PubMed) was carried out and the current state of knowledge on nephroprotective treatment strategies and the treatment of rheumatic diseases in the presence of renal insufficiency was collated, evaluated and summarized.

RESULTS

Lifestyle interventions, especially the cessation of smoking and drug treatment strategies form the basis of nephroprotection including the control of diabetes mellitus with metformin, sodium glucose transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1) analogues and control of hypertension with blockade of the renin-angiotensin-aldosterone system (RAAS), hyperlipidemia, hyperphosphatemia and metabolic acidosis. The SGLT2 inhibitors are also effective for nondiabetic nephropathy. The elevated cardiovascular risk is further reduced by effective control of inflammatory rheumatic activity. Numerous conventional disease modifying antirheumatic drugs, especially methotrexate and the Janus kinase (JAK) inhibitors baricitinib and filgotinib, must mostly be adapted to the renal function. In contrast, biologics can be given in standard doses with the exception of anakinra. The increased cardiovascular risk currently limits the use of tofacitinib in patients with renal insufficiency.

CONCLUSION

The antirheumatic medication should be modified and a complex nephroprotective treatment concept is mandatory in the management of patients with rheumatic disease and renal insufficiency, that in the best-case scenario can be guaranteed by a close interdisciplinary cooperation of rheumatologists and nephrologists.

[The role of hyponatremia in the rapid onset of coma after Cyclophosphamide]

INTRODUCTION

Cyclophosphamide is an alkylating agent used in routine pulmonary practice, particularly in the management of connectivitis-related diffuse interstitial lung disease. Common side effects are gastrointestinal disorders and immunosuppression, and a sudden and exceptional adverse effect is severe hyponatremia.

OBSERVATION

A 78-year-old female patient treated for NSIP-OP in the context of an anti-synthetase syndrome was treated with Cyclophosphamide 15mg/kg. Twenty-four hours after the end of the infusion, she was diagnosed at home in a coma with comitial seizures. Biological assessment revealed severe hyponatremia at 109 mmol/l with blood hypo-osmolarity. The patient's condition rapidly improved following correction of the ionic disorder.

CONCLUSION

Hyponatremia induced by low-dose Cyclophosphamide is a rare but serious adverse effect that requires special attention.

Severe Hyponatremia During First Cycle of Cyclophosphamide/Doxorubicin Chemotherapy

Syndrome of inappropriate anti-diuretic hormone release (SIDAH) is a condition characterized by an unregulated release of anti-diuretic hormone (ADH) resulting in increased water retention and decreased plasma osmolarity. Without regulation, ADH release will cause a significant decrease in plasma sodium concentration and can present with cramping, nausea, vomiting, and in severe cases, seizures, and potentially falling into a comatose state. The causes of SIADH are variable and range from infections, some malignancies to some medications. We report a rare case of SIADH resulting from a single cycle of doxorubicin and cyclophosphamide chemotherapy in a 66-year-old female with left and right, estrogen receptor positive breast cancer who experienced seizures resulting from a dramatic drop in sodium levels.