Coronavirus disease of 2019 (COVID-19) is the respiratory viral infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite being a primary respiratory illness, it is commonly complicated by systemic involvement of the vasculature leading to arterial and venous thrombosis. In this review, we will focus on the association between COVID-19 and thrombosis. We will highlight the pathophysiology of COVID-19 coagulopathy. The clinical manifestations of COVID-19 vasculopathy will be discussed with a focus on venous and arterial thromboembolic events. COVID-19 vasculopathy and disseminated intravascular coagulation (DIC) are distinguished within, as well as areas of controversy, such as “long COVID”. Finally, the current professional guidelines on prevention and treatment of thrombosis associated with SARS-CoV-2 infection will be discussed.

Characterized by bone marrow dysplasia and peripheral blood monocytosis, chronic myelomonocytic leukemia (CMML) is one of the most aggressive chronic leukemias and has a propensity for progression to acute myeloid leukemia (AML). Patients with newly diagnosed AML generally present with symptoms related to complications of pancytopenia but can also present with renal insufficiency. We present a 79-year-old male with a past medical history of CMML and chronic kidney disease stage 3 (baseline creatinine 1.8 mg/dL) who presented with one day of inability to urinate and 20-lb unintentional weight loss, fatigue, and bone pain over 3 months. Laboratory evaluation revealed leukocytosis of 88.5 x 10³/uL (normal 4.8–10.8 x 10³/uL) with 24.0% monocytes on differential, creatinine 2.94 mg/dL (baseline creatinine 1.7–1.9 mg/dL), uric acid 19.8 mg/dL, potassium 4.0 mmol/L, phosphorus 4.0 mg/dL, calcium 9.2 mg/dL, and albumin 3.2 g/dL. Urinalysis was significant for protein 200 mg/dL, 20/LPF granular casts, and 7/LPF hyaline casts. Bone marrow biopsy revealed 20–30% blasts with monocytic features of differentiation consistent with acute myeloid leukemia. Computed tomography (CT) of the abdomen and pelvis appreciated splenomegaly with retroperitoneal, and pelvic lymphadenopathy. Kidney failure can complicate the presentation of AML but can be rapidly reversible with treatment. In patients with CMML who have progressive renal insufficiency and hyperuricemia, there should be a high index of suspicion for progression to AML.

IgG deficiency can predispose to recurrent pyogenic infections. The association of IgG deficiency withClostridium difficileinfection has been infrequently reported in the literature. We present a case of a middle-age woman with multiple hospitalizations for recurrentC. difficilein a short span of time which prompted consideration of a possible fecal transplant. On evaluation, she was found to have low total IgG, with subclass analysis revealing low IgG1 and IgG3. She was started on monthly infusions of immunoglobulins and one year after her last episode ofC. difficileshe has not had any recurrence. The role of immunoglobulin infusion in the treatment of recurrentC. difficileis controversial, with some studies revealing no clear evidence of benefit. Our case report suggests that the patients who have underlying IgG deficiency may benefit from immunoglobulin, as this can significantly reduce the incidence of recurrent infections and hence save the healthcare costs.

Acute portal vein thrombosis represents a less common type of venous thromboembolism, even among the prothrombotic complications of coronavirus disease 2019 (COVID-19). Such complications are primarily reported during the active phase of infection. The case here describes acute portal vein thrombosis following resolution of COVID-19 in a 44-year-old male who presented with abdominal pain. Abdominal imaging identified portal and other splanchnic vein thromboses. Studies for hypercoagulable conditions were negative. Polymerase chain reaction was negative for severe acute respiratory syndrome coronavirus-2; however, IgG serology was positive. The case highlights the importance of considering thrombotic complications, particularly splanchnic vein thromboses, in patients with recent COVID-19.