Thrombotic thrombocytopenic purpura (TTP) is the prototypical microangiopathy characterized by disseminated microthromboses, hemolytic anemia, and ultimately organ dysfunction. A link with deficiency of the von Willebrand factor–cleaving protease (ADAMTS13) has been demonstrated, but additional genetic and/or environmental triggers are thought to be required to incite acute illness. Here we report that 4 days of ADAMTS13 functional inhibition is sufficient to induce TTP in the baboon (Papio ursinus), in the absence of inciting triggers because injections with an inhibitory monoclonal antibody (mAb) consistently (n = 6) induced severe thrombocytopenia (< 12 × 109/L), microangiopathic hemolytic anemia, and a rapid rise in serum lactate dehydrogenase. Immunohistochemical staining revealed the characteristic disseminated platelet- and von Willebrand factor–rich thrombi in kidney, heart, brain, and spleen but not lungs. Prolonged inhibition (14 days, n = 1) caused myocardial ischemic damage and asplenia but not death. Control animals (n = 5) receiving equal doses of a noninhibitory anti-ADAMTS13 mAb remained unaffected. Our results provide evidence for a direct link between TTP and ADAMTS13 inhibition and for a mild disease onset. Furthermore, we present a reliable animal model of this disease as an opportunity for the development and validation of novel treatment strategies.

The present prospective, multinational, noninterventional study aimed to document and describe real-world treatment regimens and disease progression in multiple myeloma (MM) patients. Adult patients initiating any new MM therapy from October 2010 to October 2012 were eligible. A multistage patient/site recruitment model was applied to minimize the selection bias; enrollment was stratified by country, region, and practice type. The patient medical and disease features, treatment history, and remission status were recorded at baseline, and prospective data on treatment, efficacy, and safety were collected electronically every 3 months. A total of 2358 patients were enrolled. Of these patients, 775 and 1583 did and did not undergo stem cell transplantation (SCT) at any time during treatment, respectively. Of the patients in the SCT and non-SCT groups, 49%, 21%, 14%, and 15% and 57%, 20%, 12% and 10% were enrolled at treatment line 1, 2, 3, and ≥ 4, respectively. In the SCT and non-SCT groups, 45% and 54% of the patients had received bortezomib-based therapy without thalidomide/lenalidomide, 12% and 18% had received thalidomide/lenalidomide-based therapy without bortezomib, and 30% and 4% had received bortezomib plus thalidomide/lenalidomide-based therapy as frontline treatment, respectively. The corresponding proportions of SCT and non-SCT patients in lines 2, 3, and ≥ 4 were 45% and 37%, 30% and 37%, and 12% and 3%, 33% and 27%, 35% and 32%, and 8% and 2%, and 27% and 27%, 27% and 23%, and 6% and 4%, respectively. In the SCT and non-SCT patients, the overall response rate was 86% to 97% and 64% to 85% in line 1, 74% to 78% and 59% to 68% in line 2, 55% to 83% and 48% to 60% in line 3, and 49% to 65% and 36% and 45% in line 4, respectively, for regimens that included bortezomib and/or thalidomide/lenalidomide. The results of our prospective study have revealed great diversity in the treatment regimens used to manage MM in real-life practice. This diversity was linked to factors such as novel agent accessibility and evolving treatment recommendations. Our results provide insight into associated clinical benefits.

Rare thromboembolic events have been observed during the vaccination rollout, which have prompted cautionary pauses in vaccinations by some regulatory authorities, including the South Africa Health Products Regulatory Authority.^1,2 Here, we report interim safety data from the first 288,368 participants who were vaccinated with Ad26.COV2.S in the Sisonke study — an open label, single-group, phase 3b implementation study to monitor the effectiveness of the single-dose Ad26.COV2.S vaccine among 500,000 health care workers in South Africa (ClinicalTrials.gov number, NCT04838795). Enrollment in the study began on February 17, 2021, and as of April 12, 2021, a total of 288,368 health care workers had received the Ad26.COV2.S vaccine, among whom 5898 (2%) reported adverse events.

Little is known about the pathway to diagnosis of lymphoma in Sub-Saharan Africa, despite the increased risk of lymphoma in people living with HIV (PLHIV). The challenges of diagnosis in this setting include diagnostic confusion with extrapulmonary tuberculosis (EPTB), which commonly causes lymphadenopathy in PLHIV. We analysed the time to diagnosis and treatment in patients using predetermined time intervals. Univariate and multivariable analyses were performed to determine the relationship between patient and disease-specific variables with delays to diagnosis. We were particularly interested in the impact of HIV, empiric tuberculosis therapy and fine-needle aspirate for cytology (FNAC) in contributing to delay. Patients (n = 163), 29% HIV-infected, waited a median of 4 weeks before seeking medical attention. It took a median of 7 weeks for the diagnosis of lymphoma to be made from the time the patient sought medical attention, termed the healthcare practitioner interval. In multivariable logistic regression analysis, diagnostic delay > 6 weeks was associated with late-stage disease (OR 2.3, 95% CI 1.1–5.2) and Hodgkin lymphoma (HL) (OR 3.0, 95% CI 1.1–8.0). HIV status was not associated with diagnostic delay (OR 0.9, 95% CI 0.3–2.2). The median time to diagnosis was a median of 4 weeks longer for patients on tuberculous (TB) therapy (n = 16, p = 0.28) and patients who underwent an FNAC (n = 63, p = 0.04). Where FNAC was performed, it was diagnostic for lymphoma in only 11%. Diagnostic delay was not associated with overall survival. Time-to-diagnosis of lymphoma in South Africa was similar to that reported from high-income countries and shows significant periods of delay between the onset of symptoms to diagnosis and treatment. The longest period of delay was in the health practitioner interval. Education regarding the significance of lymphadenopathy for both patients and health care practitioners and appropriate investigative steps preferably by best-practice algorithms specific to TB-endemic areas are needed to shorten the time-to-diagnosis of lymphoma.