An Unusual Case of Hemophagocytic Lymphohistiocytosis Associated with Mycobacterium chimaera or Large-Cell Neuroendocrine Carcinoma

Hemophagocytic lymphohistiocytosis (HLH) is a rare and very dangerous condition characterized by abnormal activation of the immune system, causing hemophagocytosis, inflammation, and potentially widespread organ damage. The primary (genetic) form, caused by mutations affecting lymphocyte cytotoxicity, is most commonly seen in children. Secondary HLH is commonly associated with infections, malignancies, and rheumatologic disorders. Most current information on diagnosis and treatment is based on pediatric populations. HLH is a disease that should be diagnosed and treated promptly, otherwise it is fatal. Treatment is directed at treating the triggering disorder, along with symptomatic treatment with dexamethasone and etoposide. We present a 56-year-old patient who was admitted with worsening weakness, exertional dyspnea, dry and nonproductive cough, and a 5-pound weight loss associated with loss of appetite. This is among the rare disorders that are not commonly encountered in day-to-day practice. Our differential diagnoses were broad, including infection, such as visceral leishmaniasis, atypical/tuberculous mycobacteria, histoplasmosis, Ehrlichia, Bartonella, Brucella, Adenovirus, disseminated herpes simplex virus (HSV), hematological-like Langerhans cell histiocytosis, or multicentric Castleman disease; drug reaction, such as drug rash with eosinophilia and systemic symptoms (DRESS); and metabolic disorder, including Wolman's disease (infantile lysosomal acid lipase deficiency) or Gaucher's disease. Based on our investigations as described in our case report, it was narrowed down to hemophagocytic lymphohistiocytosis and COVID-19. Two COVID-19 tests were negative. His lab abnormalities and diagnostic testing revealed hemophagocytic lymphohistiocytosis. He was empirically started on antibiotics and dexamethasone, to be continued for 2 weeks then tapered if the patient showed continued improvement. Dexamethasone was tapered over 8 weeks. He improved on just one of the Food and Drug Administration (FDA)-approved medications, proving that treatment should be tailored to the patient. In addition, in this case study, we included the background, etiology, pathogenesis, diagnosis, management, and prognosis of HLH.

Falsely positive heparin-induced thrombocytopenia antibody testing in severe hyperbilirubinemia

Heparin-induced thrombocytopenia (HIT) is a life-threatening pathologic reaction to heparin-based products. Diagnosis of this condition can be confounded by other comorbidities or by acute illness-oftentimes presenting challenging clinical dilemmas, particularly in critically ill patients. A 67-year-old woman was admitted with liver failure and severe hyperbilirubinemia. She developed thrombocytopenia after prophylactic heparin exposure. Subsequent quantitative latex immunoturbidimetric assay (LIA) HIT antibody testing was intermediately positive. Confirmatory serotonin release assay testing subsequently returned negative. Platelet factor4-dependent P-selectin expression assay also returned negative, suggesting false positivity of the initial LIA tests. Concern was raised that hyperbilirubinemia (total bilirubin, 55.5 mg/dL) interfered with the original assay. Further testing with a separate HIT ELISA assay, which includes multiple washes and dilutions of the serum in order to effectively remove bilirubin, returned negative. Medical providers must consider the possibility of false-positive LIA testing when evaluating for HIT in the setting of severe hyperbilirubinemia.

Survival Disparities of Diffuse Large B-Cell Lymphoma in a Community-Based Inner-City Cancer Center

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) comprises approximately 30% of all non-Hodgkin lymphomas. Multiple studies have demonstrated race-based disparities in survival among patients with DLBCL across all stages of disease, in the era both before and after rituximab. The etiology for the racial disparities in survival among patients with DLBCL is still unknown. Moreover, the Revised International Prognostic Index (R-IPI), a tool that predicts the DLBCL patients' outcome, has not yet been validated in African Americans (AA).

PATIENTS AND METHODS

We conducted a cohort study of patients diagnosed with DLBCL from January 1, 2007, to December 31, 2017, from our tumor registry in a single community-based inner-city cancer center. We abstracted demographic, clinical, histopathologic, treatment, and R-IPI variables. A total of 181 patients (47.5%) with biopsy-proven DLBCL were included in the retrospective analysis. The median age was 65 years, 47% were men, 41% were AA, and 44% were white.

RESULTS

The AA group had a younger median age, higher lactate dehydrogenase levels, higher frequency of B symptoms, and higher HIV infection than the non-AA group. The AA group had significantly decreased median overall survival than the non-AA group (15.7 months; 95% confidence interval, 10.3 to 23.9, vs. 93.6 months; 95% confidence interval, 61.5 to 142.6, respectively; P < .001). The survival disparities persisted after excluding patients with HIV and who did not receive chemotherapy. In addition, AA race predicts a reduced survival by univariate and multivariate analysis.

CONCLUSION

AA with DLBCL may have a poorer prognosis than the non-AA population. Further studies should investigate the biology of DLBCL in the AA population.

Development of new cold antibodies in a patient with a history of warm autoimmune haemolytic anaemia

A 31-year-old male presented to our facility with complaints of shortness of breath and left-sided chest pain. On record review, it was revealed that he had been seen in 2014 for an almost identical presentation and had been found to have haemolytic anaemia with warm autoantibodies. Following his acute treatment during that hospital admission, he was lost to follow-up. During his subsequent admission, 5 years later, he was found to have a systemic autoimmune disorder with a superimposed acute bacterial infection leading to a second case of haemolytic anaemia and at this time with both cold and warm antibodies present. While his diagnosis was initially difficult to make due to both derangements in expected laboratory values and the mixed pattern of the haemolytic anaemia, he was promptly treated with intravenous immune globulin and steroids and was able to make a full recovery.

Clinical Advancement and Challenges of ex vivo Expansion of Human Cord Blood Cells

Apart from peripheral blood stem cell (PBSC), umbilical cord blood (UCB) is now a recognized source of stem cells for transplantation. UCB is an especially important source of stem cells for minority populations, which would otherwise be unable to find appropriately matched adult donors. UCB has fewer mature T lymphocytes compared with peripheral blood, thus making a UCB transplantation (UCBT) with a greater degree of HLA mismatch possible. The limited cell dose per UCB sample is however associated with delayed engraftment and a higher risk of graft failure, especially in adult recipients. This lower cell dose can be optimized by performing double unit UCBT, ex vivo UCB expansion prior to transplant and enhancement of the capabilities of the stem cells to home to the bone marrow. UCB contains naïve and immature T cells, thus posing significant challenges with increased risk of infections, graft versus host diseases (GVHD) and relapse following UCBT. Cell engineering techniques have been developed to circumnavigate the immaturity of the T cells, and include virus-specific cytotoxic T cells (VSTs), T cells transduced with disease-specific chimeric antigen receptor (CAR T cells) and regulatory T cell (Tregs) engineering. In this article, we review the advances in UCB ex vivo expansion and engineering to improve engraftment and reduce complications. As further research continues to find ways to overcome the current challenges, outcomes from UCBT will likely improve.

Real World Utility of Dobutamine Stress Echocardiography in Predicting Perioperative Cardiovascular Morbidity and Mortality after Orthotopic Liver Transplantation

Background and Objectives

Stress echocardiography is the current standard for cardiac risk stratification of patients undergoing orthotopic liver transplantation (OLT). We aim to evaluate the role of dobutamine stress echocardiography (DSE) in predicting perioperative major adverse cardiac event (MACE) in patients undergoing OLT.

Methods

This was a single-center retrospective study including 144 OLT patients. Of 144 patients, 118 had DSE. MACE included myocardial infarction (MI), heart failure (HF), cardiovascular and all-cause death 1 year after OLT.

Results

Our study cohort included 118 patients. The mean age was 57.3±8.2 years (range, 25–72 years). There were 85 men and 33 women, male to female ratio being 2.6:1. Of 118, 15 (13%) had positive DSE and 103 (87%) had negative DSE. Perioperative MACE incidence was 5.9% (95% confidence interval [CI], 2.6–12.3%). In predicting MACE, DSE had sensitivity of 5.6% (95% CI, 0.2–29.4%), specificity 86% (95% CI, 77.3–91.9%), positive predictive value 6.7% (95% CI, 0.3–33.4%), and negative predictive value (NPV) 83.5% (95% CI, 74.6–89.8%). Eighteen patients had MACE in first year post OLT (15%, 95% CI, 9.5–23.3%). Adverse events included cardiogenic shock (2/18), systolic HF (2/18), non-ST-elevated MI (7/18), cardiac mortality (3/18), and all-cause mortality (7/18). The overall complication rate of DSE was 17% (20/118).

Conclusions

In our cohort, DSE had a low sensitivity but high NPV in predicting perioperative MACE post OLT. A similar trend was noted for DSE in predicting 1-year MACE post OLT. We reiterate the need of a better screening and risk stratification tool for OLT.

New resources for genetic studies in Populus nigra: genome-wide SNP discovery and development of a 12k Infinium array

Whole genome resequencing of 51 Populus nigra (L.) individuals from across Western Europe was performed using Illumina platforms. A total number of 1 878 727 SNPs distributed along the P. nigra reference sequence were identified. The SNP calling accuracy was validated with Sanger sequencing. SNPs were selected within 14 previously identified QTL regions, 2916 expressional candidate genes related to rust resistance, wood properties, water-use efficiency and bud phenology and 1732 genes randomly spread across the genome. Over 10 000 SNPs were selected for the construction of a 12k Infinium Bead-Chip array dedicated to association mapping. The SNP genotyping assay was performed with 888 P. nigra individuals. The genotyping success rate was 91%. Our high success rate was due to the discovery panel design and the stringent parameters applied for SNP calling and selection. In the same set of P. nigra genotypes, linkage disequilibrium throughout the genome decayed on average within 5-7 kb to half of its maximum value. As an application test, ADMIXTURE analysis was performed with a selection of 600 SNPs spread throughout the genome and 706 individuals collected along 12 river basins. The admixture pattern was consistent with genetic diversity revealed by neutral markers and the geographical distribution of the populations. These newly developed SNP resources and genotyping array provide a valuable tool for population genetic studies and identification of QTLs through natural-population based genetic association studies in P. nigra.

Genetic architecture of qualitative and quantitative Melampsora larici-populina leaf rust resistance in hybrid poplar: genetic mapping and QTL detection

In order to elucidate the genetic control of resistance to Melampsora larici-populina leaf rust in hybrid poplars, a Populus deltoides x P. trichocarpa F(1) progeny was analysed for qualitative and quantitative rust resistances. This progeny was evaluated for three components of quantitative resistance (latent period, uredinia number and uredinia size) to seven M. larici-populina strains in controlled conditions, and for one component of field susceptibility (rust colonization on the most infected leaf). One qualitative resistance locus inherited from P. deltoides, R(1), was localized on the genetic map. It segregates 1 : 1 in the F(1) progeny and is effective against four of the studied strains. QTL analysis was performed separately on R(1) and r(1) genotype subsets. An additional detection was conducted on the entire F(1) progeny for the three strains able to overcome R(1) and for MAX2. A total of nine QTLs were detected. Two had large, broad-spectrum effects. One (R(US)) is inherited from the P. trichocarpa parent; the other is inherited from P. deltoides and colocalized with R(1). Seven QTLs had only limited and specific effects. Significant interaction effects were detected mainly between the two major QTLs. Implications of these results for durable resistance breeding strategies, and possible benefits from the Populus genome sequence, are discussed.

Identification of Pathotypes of Xanthomonas axonopodis pv. manihotis in Africa and Detection of Quantitative Trait Loci and Markers for Resistance to Bacterial Blight of Cassava

ABSTRACT Cassava suffers from bacterial blight attack in all growing regions. Control by resistance is unstable due to high genotype-environment interactions. Identifying genes for resistance to African strains of Xanthomonas axonopodis pv. manihotis can support breeding efforts. Five F(1) cassava genotypes deriving from the male parent 'CM2177-2' and the female parent 'TMS30572' were used to produce 111 individuals by backcrossing to the female parent. In all, 16 genotypes among the mapping population were resistant to stem inoculation by four strains of X. axonopodis pv. manihotis from different locations in Africa, and 19 groups with differential reactions to the four strains were identified, suggesting that the strains represent different pathotypes. Four genotypes were resistant to leaf inoculation, and three were resistant to both stem and leaf inoculations. Genotypes with susceptible, moderately resistant, and resistant reactions after leaf and stem inoculation partly differed in their reactions on leaves and stems. Based on the genetic map of cassava, single-markeranalysis of disease severity after stem-puncture inoculation was performed. Eleven markers were identified, explaining between 16 and 33.3% of phenotypic variance of area under disease progress curve. Five markers on three and one linkage groups from the female- and male-derived framework of family CM8820, respectively, seem to be weakly associated with resistance to four strains of X. axonopodis pv. manihotis. Based on the segregation of alleles from the female of family CM8873, one marker was significantly associated with resistance to two X. axonopodis pv. manihotis strains, GSPB2506 and GSPB2511, whereas five markers were not linked to any linkage group. The quantitative trait loci (QTL) mapping results also suggest that the four African strains belong to four different pathotypes. The identified pathotypes should be useful for screening for resistance, and the QTL and markers will support breeding for resistance.