A Rare Case of Atypical Hemolytic Uremic Syndrome (aHUS) Precipitated by Dengue and the Treatment Landscape in Singapore.

Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by uncontrolled complement activation due to complement dysregulation. It is often triggered by precipitating events such as infections, inflammation, pregnancy, or medications. Dengue, an endemic viral infection in Southeast Asia, can activate the complement pathway, thereby triggering aHUS in genetically susceptible individuals. Here, we present the case of a 33-year-old male who presented with Dengue fever and subsequently developed aHUS. Plasma exchange (PLEX) successfully normalized his neurological status and hematological parameters. Although his renal function improved, it failed to normalize. Eculizumab, a monoclonal antibody that inhibits C5, was administered for a total of six months. The treatment was successfully discontinued without evidence of relapse after six months of follow-up. This case report demonstrates the safety of discontinuing eculizumab in patients who do not possess pathogenic mutations or variants in complement factors.

High-dose methotrexate is effective for prevention of isolated CNS relapse in diffuse large B cell lymphoma.

The role of central nervous system (CNS) prophylaxis with high-dose methotrexate (HDMTX) in DLBCL is controversial. In this retrospective study, we evaluated the efficacy of prophylactic HDMTX on isolated CNS relapse, concomitant CNS and systemic relapse, systemic relapse, and survival outcomes in 226 patients with newly diagnosed DLBCL and high-risk CNS International Prognostic Index (CNS-IPI) score treated with RCHOP. The three-year risk of isolated CNS relapse was significantly lower in patients who received HDMTX, at 3.1% compared to 14.6% (P = 0.032) in those who did not. However, neither concomitant CNS-systemic relapse rates, systemic relapse rates, nor three-year PFS and OS were significantly different between treatment groups in multivariable analysis. Among propensity score-matched patients (N = 102), HDMTX was also associated with significantly lower isolated CNS relapse rates (HR 0.06, 95% CI 0.004-0.946, P = 0.046). HDMTX was well tolerated with manageable toxicities when given at a dose of 3 g/m2 by day 3 of RCHOP chemotherapy. Using propensity score matching and multivariable regression to yield treatment groups with well-balanced covariates, we showed that prophylactic HDMTX improved isolated CNS relapse rates but did not decrease concomitant CNS-systemic relapse rates, systemic relapse rates, or improve survival outcomes.

Surgical management of invasive fungal infections in adult leukemia patients: experience from a large tertiary center in Southeast-Asia.

Objectives: Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in acute leukemia patients undergoing chemotherapy or hematopoietic stem cell transplantation (HSCT). Surgical interventions may be necessary to improve the survival outcomes of these patients. The aim of this study is to report a single-center experience using surgical intervention as adjunctive treatment for IFI in adult leukemia patients. Methods: A retrospective review was conducted to obtain clinical characteristics and outcomes of surgically managed IFI patients diagnosed between January 2005 and December 2015 in our center. Results: Nineteen acute leukemia patients, median age 46 years (range 19-65), underwent 20 surgical procedures as management for IFI. Three patients had proven IFI diagnoses prior to surgery. Sixteen patients underwent surgery for both diagnostic and therapeutic purposes. Post-surgery, the diagnostic yield for proven IFI increased by a factor of 5, and 15 patients had definitive IFI diagnoses. Surgical complications included 2 pleural effusions, 4 pneumothoraxes, and 1 hydropneumothorax. The median duration of hospitalization for patients with complications was 9 days (range 3-64). Thirteen patients benefited overall from the procedure, 3 had temporary clinical benefits, and 2 had progression of IFI. After surgery, the 3-month and 2-year overall survival rates were 89.5% and 57.9%, respectively. The median time from surgery to resumption of chemotherapy or HSCT was 25 days. Conclusions: Surgical interventions for IFI are feasible in selected leukemia patients, as they yield valuable information to guide antifungal therapy or enable therapeutic outcomes with acceptable risk, thereby allowing patients to proceed with curative chemotherapy and HSCT.