Infectious mononucleosis due to Epstein-Barr virus reactivation in an immunocompromised 60-year-old patient with COVID-19.

Epstein-Barr virus (EBV) reactivation in COVID-19 patients has been reported, but studies on its clinical significance are lacking. We herein report the occurrence of infectious mononucleosis (IM) due to EBV reactivation in a 60-year-old man with rheumatoid arthritis being treated with methotrexate and tocilizumab. The patient presented with a fever and tested positive for COVID-19. Laboratory findings revealed an increased atypical lymphocyte count, decreased platelet count, and elevated liver enzyme levels. Flow cytometry showed predominant expansion of reactive T cells. EBV reactivation was confirmed using real-time polymerase chain reaction. The patient was treated with remdesivir, and clinical improvement was observed after 10 days of treatment. Follow-up showed a gradual decrease in the EBV-DNA load with no recurrence of atypical lymphocytes. These findings suggest that COVID-19 in immunocompromised patients may lead to unexpected EBV reactivation and IM, even for patients outside the age at which IM is likely to occur.

[Primary renal triple expressor DLBCL treated with chemotherapy under continuous hemodialysis and filtration support].

A 69-year-old woman was previously treated with antibiotics for suspected pyelonephritis due to fever but showed limited improvement. Contrast-enhanced CT revealed heterogeneous areas of decreased contrast enhancement in both kidneys, along with an elevated soluble level of the IL-2 receptor (5,090 U/ml), and thus the patient was referred to our department for further evaluation. A percutaneous renal biopsy performed due to suspected malignant lymphoma confirmed lymphoma cell infiltration into the renal interstitium. Immunohistochemical staining was positive for MYC/BCL2/BCL6, leading to the diagnosis of stage IVB primary renal triple expressor diffuse large B cell lymphoma (DLBCL). Due to acute kidney injury, continuous hemodiafiltration (CHDF) was initiated, followed by rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. The patient's renal function improved rapidly, and complete response was achieved after six cycles of R-CHOP. Although DLBCL is a common lymphoma, the primary renal subtype is extremely rare and poses both diagnostic and therapeutic challenges. This case highlights the potential clinical implications of combining CHDF with chemotherapy to achieve complete response despite an initial poor prognosis based on the patient's overall clinical condition and pathology.

Sudden-onset gallbladder rupture due to Ceftriaxone-associated pseudolithiasis in a patient with acquired hemophilia A.

We herein report a 76-year-old man with acquired hemophilia A (AHA) who developed gallbladder rupture due to Ceftriaxone (CTRX)-associated pseudolithiasis. The patient was admitted for an examination of systemic subcutaneous bleeding. A blood test showed a prolonged activated partial thromboplastin time and sequentially revealed low factor VIII activity (<1%) and a high factor VIII inhibitor level of 143 BU/mL. The patient was thus diagnosed with AHA. After admission, he developed a high-grade fever and was administered intravenous CTRX, considering the possibility of psoas abscess or cellulitis. Although his high-grade fever was improved, computed tomography incidentally showed a high-density lesion in the gallbladder, suggestive of CTRX-associated pseudolithiasis without clinical symptoms. Despite cessation of CTRX, the pseudolithiasis never disappeared, and the patient suddenly died after rapid progression of abdominal bloating. An autopsy revealed that the gallbladder was severely swollen and had ruptured with hemorrhaging because of hemorrhagic cholecystitis, caused by CTRX-associated pseudolithiasis with AHA. Our case demonstrated that CTRX-associated pseudocholelithiasis can unexpectedly induce gallbladder hemorrhaging and rupture in a patient with a bleeding diathesis, including AHA. CTRX-associated pseudocholelithiasis can cause a fatal outcome in patients with a bleeding disorder, even if CTRX is ceased as soon as pseudocholelithiasis is detected.

[Hypomagnesemia induced by gastrointestinal losses due to carfilzomib].

A 67-year-old man with multiple myeloma had been treated with carfilzomib, lenalidomide, and dexamethasone (KRd) therapy. During the second course, he developed dyspnea, which gradually worsened. After admission, gastrointestinal losses of magnesium were confirmed, and intravenous magnesium was administered, which consequently improved his symptoms. Although KRd therapy was resumed, hypomagnesemia was recurring. Therefore, carfilzomib was replaced with ixazomib, which improved the patient's hypomagnesemia. The major causes of hypomagnesemia are gastrointestinal and renal losses; our case appeared to have gastrointestinal losses of magnesium and was successfully treated by discontinuing carfilzomib. Hypomagnesemia should be considered in patients receiving carfilzomib; furthermore, clinicians should consider discontinuing carfilzomib as its treatment.

[Successful Treatment with Pomalidomide, Bortezomib, and Dexamethasone in a Patient with Frail Refractory and Relapsed Multiple Myeloma with Extramedullary Disease].

An 85-year-old female was diagnosed with multiple myeloma(MM)(IgG-l)with t(4 ;14)(p16;q32)in 200X. She received bortezomib with dexamethasone(Vd)therapy and lenalidomide with dexamethasone(Ld)therapy, and she subsequently maintained a very good partial response(VGPR). On day 731, she experienced relapse and was treated with 2 courses of elotuzumab with Ld therapy. However, on day 794, she experienced relapse with plasmacytoma, and was treated with 2 courses of pomalidomide and low-dose dexamethasone(Pd), 2 courses of cyclophosphamide with Pd(PCd), and bortezomib with Pd(PVd)therapies. After 3 courses of PVd therapy, she achieved PR. She has continued to receive 11 courses of PVd therapy and has not suffered any adverse events(BGrade 3). These findings suggest that PVd therapy is a relatively safe and highly efficacious treatment for frail patients with relapsed and refractory MM who have previously received both lenalidomide and bortezomib. Further studies are needed to establish treatment efficacy and safety in frail patients with relapsed and refractory MM with extramedullary disease.

Successful management of venous thromboembolism with apixaban in a multiple myeloma patient on lenalidomide therapy.

A 69-year-old man was diagnosed with multiple myeloma (IgG-κ) in January 2012. He received autologous hematopoietic stem cell transplantation in August 2012 and subsequently maintained a stringent complete remission. In March 2016, he relapsed and was treated with lenalidomide and low-dose dexamethasone (Ld). On day22, he developed an asymptomatic venous thromboembolism (VTE) despite receiving prophylactic aspirin treatment. Thus, heparin and warfarin were administered. However, his prothrombin time-international normalized ratio did not remain within the target range of 2-3. Therefore, 10 mg/day of apixaban, a factor Xa inhibitor, was administered. The apixaban treatment resulted in favorable and effective control of the patient's VTE on day33. He has continued to receive Ld treatment and has suffered no further VTE or bleeding. Further large studies are needed to assess the efficacy and safety of factor Xa inhibitors for the treatment of MM-associated VTE.

Intravascular hemolytic anemia in a patient with antibodies related to meropenem.

A 76-year-old woman treated with meropenem developed intravascular hemolytic attacks. A direct antiglobulin test was positive for C3d and IgG, and drug-dependent antibody testing indicated that the antibodies were indeed drug-dependent and reacted with drug-treated RBCs and RBCs in the presence of the drug. To our knowledge, this is the first reported case in which the causative antibodies related to meropenem were identified. This case highlights the importance of maintaining a high level of suspicion for drug-induced immune hemolytic anemia in patients with explained hemolysis as well as conducting specialized serologic testing.