Repeated COVID-19 vaccination to maximum antibody response yields very low mortality and hospitalisation rates in patients with CLL and MBL

We analysed COVID-19 infection outcomes of 129/241 chronic lymphocytic leukaemia (CLL) (53.9%) and 22/55 monoclonal B-lymphocytosis (MBL) (40.0%) patients following multiple vaccine doses aiming for maximum measured anti-spike antibody response. Throughout the pandemic to date, there were 8/129 CLL (6.2%) patients hospitalised, with one death (0.8%). No MBL patients were hospitalised or died. CLL patients with COVID-19 had lower anti-spike levels (3778.8 AU/mL) than those without (13 486.8 AU/mL; p = 0.0061). Anti-nucleocapsid antibody was detected in 29.8% within 2 months and 17.5% >6 months. Of COVID-19-infected CLL patients, 47.3% received anti-viral therapy. A multiple vaccine dosing strategy to achieve measured maximum antibody is highly effective in preventing severe COVID-19.

Immune cell kinetics and antibody response in COVID-19 patients with low-count monoclonal B-cell lymphocytosis

Low-count monoclonal B-cell lymphocytosis (MBLlo ) has been associated with an underlying immunodeficiency and has recently emerged as a new risk factor for severe COVID-19. Here, we investigated the kinetics of immune cell and antibody responses in blood during COVID-19 of MBLlo versus non-MBL patients. For this study, we analyzed the kinetics of immune cells in blood of 336 COVID-19 patients (74 MBLlo and 262 non-MBL), who had not been vaccinated against SARS-CoV-2, over a period of 43 weeks since the onset of infection, using high-sensitivity flow cytometry. Plasma levels of anti-SARS-CoV-2 antibodies were measured in parallel by ELISA. Overall, early after the onset of symptoms, MBLlo COVID-19 patients showed increased neutrophil, monocyte, and particularly, plasma cell (PC) counts, whereas eosinophil, dendritic cell, basophil, and lymphocyte counts were markedly decreased in blood of a variable percentage of samples, and with a tendency toward normal levels from week +5 of infection onward. Compared with non-MBL patients, MBLlo COVID-19 patients presented higher neutrophil counts, together with decreased pre-GC B-cell, dendritic cell, and innate-like T-cell counts. Higher PC levels, together with a delayed PC peak and greater plasma levels of anti-SARS-CoV-2-specific antibodies (at week +2 to week +4) were also observed in MBLlo patients. In summary, MBLlo COVID-19 patients share immune profiles previously described for patients with severe SARS-CoV-2 infection, associated with a delayed but more pronounced PC and antibody humoral response once compared with non-MBL patients.

Is it possible to predict post-adenotonsillectomy hemorrhage in children with preoperative blood tests? Single-center retrospective study

Introduction: Post-adenotonsillectomy (PAT) bleeding, a life-threatening surgical complication, remains unpredictable despite preoperative blood tests. Every surgeon would like predictive markers for this complication of one of the most common procedures performed in pediatric ear, nose, and throat (ENT). Objective: The purpose of the study is to see whether the results of the blood tests we perform routinely preoperatively in children undergoing adenotonsillectomy (AT) (lymphocyte count and percentage, C reactive protein, fibrinogen, or coagulation variables International Normalized Ratio and activated partial thromboplastin time) can potentially predict early post-AT bleeding. Focus has been placed on the presence of relative lymphocytosis (a value of lymphocyte percentage above 55%) in the blood cell count of the patients and its possible connection to postoperative hemorrhage. Method: We conducted an observational retrospective study on 801 children undergoing adenoidectomy, tonsillectomy, or AT over a period of 6 months in our ENT department. Statistical analysis was performed to compare the data. Results: we did not find a statistically significant correlation between preoperative blood markers (coagulation or inflammatory) and early post-AT bleeding. An important blood marker in relation to PAT bleeding appears to be relative lymphocytosis. Relative lymphocytosis has a weak predictive value of early postoperative bleeding in children with AT (sensitivity of only 31.58%, but acceptable specificity of above 80%). In other words, 80% of patients without relative lymphocytosis will not bleed in the first 24 h postoperatively. Children with relative lymphocytosis may need tighter surveillance in the first 24 h after AT. Conclusions: Relative lymphocytosis has a weak predictive value of early postoperative bleeding in children with AT children.

Subcutaneous panniculitis-like T-cell lymphoma in two unrelated individuals with BENTA disease

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous non-Hodgkin lymphoma involving CD8+ T cells, the genetic underpinnings of which remain incompletely understood. Here we report two unrelated patients with B cell Expansion with NF-κB and T cell Anergy (BENTA) disease and a novel presentation of SPTCL. Patient 1 presented early in life with recurrent infections and B cell lymphocytosis, linked to a novel gain-of-function (GOF) CARD11 mutation (p.Lys238del). He developed SPTCL-like lesions and membranoproliferative glomerulonephritis by age 2, treated successfully with cyclosporine. Patient 2 presented at 13 months with splenomegaly, lymphadenopathy, and SPTCL with evidence of hemophagocytic lymphohistiocytosis. Genetic analysis revealed two in cis germline GOF CARD11 variants (p.Glu121Asp/p.Gly126Ser). Autologous bone marrow transplant resulted in SPTCL remission despite persistent B cell lymphocytosis. These cases illuminate an unusual pathological manifestation for BENTA disease, suggesting that CARD11 GOF mutations can manifest in cutaneous CD4+and CD8+ T cell malignancies.

Bone marrow haematopoiesis in patients with COVID-19

AIMS

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection broadly affects organ homeostasis, including the haematopoietic system. Autopsy studies are a crucial tool for investigation of organ-specific pathologies. Here we perform an in-depth analysis of the impact of severe coronavirus disease 2019 (COVID-19) on bone marrow haematopoiesis in correlation with clinical and laboratory parameters.

METHODS AND RESULTS

Twenty-eight autopsy cases and five controls from two academic centres were included in the study. We performed a comprehensive analysis of bone marrow pathology and microenvironment features with clinical and laboratory parameters and assessed SARS-CoV-2 infection of the bone marrow by quantitative polymerase chain reaction (qPCR) analysis. In COVID-19 patients, bone marrow specimens showed a left-shifted myelopoiesis (19 of 28, 64%), increased myeloid-erythroid ratio (eight of 28, 28%), increased megakaryopoiesis (six of 28, 21%) and lymphocytosis (four of 28, 14%). Strikingly, a high proportion of COVID-19 specimens showed erythrophagocytosis (15 of 28, 54%) and the presence of siderophages (11 of 15, 73%) compared to control cases (none of five, 0%). Clinically, erythrophagocytosis correlated with lower haemoglobin levels and was more frequently observed in patients from the second wave. Analysis of the immune environment showed a strong increase in CD68+ macrophages (16 of 28, 57%) and a borderline lymphocytosis (five of 28, 18%). The stromal microenvironment showed oedema (two of 28, 7%) and severe capillary congestion (one of 28, 4%) in isolated cases. No stromal fibrosis or microvascular thrombosis was found. While all cases had confirmed positive testing of SARS-CoV-2 in the respiratory system, SARS-CoV-2 was not detected in the bone marrow by high-sensitivity PCR, suggesting that SARS-CoV-2 does not commonly replicate in the haematopoietic microenvironment.

CONCLUSIONS

SARS-CoV-2 infection indirectly impacts the haematological compartment and the bone marrow immune environment. Erythrophagocytosis is frequent and associated with lower haemoglobin levels in patients with severe COVID-19.

Molecular and hematological investigation of Trypanosoma evansi infection in Iranian one-humped camels (Camelus dromedarius)

Trypanosoma species cause animal trypanosomiasis that infects many animals. Trypanosoma evansi is an organism that infects camels. There are many economic problems associated with this disease, including lower milk and meat yields and abortions. The purpose of the current survey was molecular study of the presence of Trypanosoma in dromedary camel blood in the south of Iran, and its effects on the hematologic, and some acute-phase protein changes. Blood samples were aseptically collected from the jugular vein of dromedary camels (n = 100; aged from 1 to 6 years) originating from Fars Province in EDTA-coated vacutainers. Genomic DNA from 100 µL of the whole blood was extracted and amplified using a PCR assay based on ITS1, 5.8S, and ITS2 ribosomal regions. Also, the PCR products obtained were sequenced. Moreover, the changes in hematological parameters and serum acute-phase proteins (serum amyloid A, alpha-1 acid glycoprotein, and haptoglobin) were measured. Among 100 tested blood, nine samples (9%, 95% CI: 4.2-16.4%) were found positive by the PCR assay. The phylogenetic tree and blast analysis showed four different genotypes closely related to the strains (accession numbers: JN896754 and JN896755) previously reported from dromedary camels in Yazd Province, center Iran. Based on hematological analysis, normocytic and normochromic anemia and lymphocytosis were detected in the PCR-positive cases compared with the negative group. Furthermore, alpha-1 acid glycoprotein was significantly increased in the positive cases. There was a substantial and positive relation between the number of lymphocytes, and the levels of alpha-1 acid glycoprotein and serum amyloid A in the blood (p = 0.045, r = 0.223 and p = 0.036, r = 0.234, respectively). A noticeable frequency of T. evansi infection was reported in dromedary camels in south Iran. This is the first report on the genetic diversity of T. evansi in this region. There was a significant association among Trypanosoma infection, lymphocytosis, and alpha-1 acid glycoprotein. Trypanosoma-positive camels had a significant decrease in hematocrit (HCT), hemoglobin (Hb), and red blood cell (RBC) values compared to the non-infected group. Further experimental studies are needed to elucidate the hematological and acute-phase protein alteration during a different phase of Trypanosoma spp. infection.

A Nine-Gene Expression Signature Distinguished a Patient with Chronic Lymphocytic Leukemia Who Underwent Prolonged Periodic Fasting

Background and Objectives: This study aimed to investigate the causes of continuous deep fluctuations in the absolute lymphocyte count (ALC) in an untreated patient with Chronic Lymphocytic Leukemia (CLL), who has had a favorable prognosis since the time of diagnosis. Up until now, the patient has voluntarily chosen to adopt a predominantly vegetarian and fruitarian diet, along with prolonged periods of total fasting (ranging from 4 to 39 days) each year. Materials and Methods: For this purpose, we decided to analyze the whole transcriptome profiling of peripheral blood (PB) CD19+ cells from the patient (#1) at different time-points vs. the same cells of five other untreated CLL patients who followed a varied diet. Consequently, the CLL patients were categorized as follows: the 1st group comprised patient #1 at 20 different time-points (16 time-points during nutrition and 4 time-points during fasting), whereas the 2nd group included only one time point for each of the patients (#2, #3, #4, #5, and #6) as they followed a varied diet. We performed microarray experiments using a powerful tool, the Affymetrix Human Clariom™ D Pico Assay, to generate high-fidelity biomarker signatures. Statistical analysis was employed to identify differentially expressed genes and to perform sample clustering. Results: The lymphocytosis trend in patient #1 showed recurring fluctuations since the time of diagnosis. Interestingly, we observed that approximately 4-6 weeks after the conclusion of fasting periods, the absolute lymphocyte count was reduced by about half. The gene expression profiling analysis revealed that nine genes were statistically differently expressed between the 1st group and the 2nd group. Specifically, IGLC3, RPS26, CHPT1, and PCDH9 were under expressed in the 1st group compared to the 2nd group of CLL patients. Conversely, IGHV3-43, IGKV3D-20, PLEKHA1, CYBB, and GABRB2 were over-expressed in the 1st group when compared to the 2nd group of CLL patients. Furthermore, clustering analysis validated that all the samples from patient #1 clustered together, showing clear separation from the samples of the other CLL patients. Conclusions: This study unveiled a small gene expression signature consisting of nine genes that distinguished an untreated CLL patient who followed prolonged periods of total fasting, maintaining a gradual growth trend of lymphocytosis, compared to five untreated CLL patients with a varied diet. Future investigations focusing on patient #1 could potentially shed light on the role of prolonged periodic fasting and the implication of this specific gene signature in sustaining the lymphocytosis trend and the favorable course of the disease.

Concurrent development of small lymphocytic lymphoma and lung cancer: A report of two cases and a review of the literature

Small lymphocytic lymphoma (SLL) is a rare disease subtype which has the same morphological and immunophenotypic features as chronic lymphocytic leukemia (CLL) but does not demonstrate lymphocytosis and grows mainly in the lymph nodes and spleen. As with CLL, SLL patients tend to present with immune abnormalities, and are associated with an increased risk for developing second primary malignancies. We report here two cases of SLL who developed lung cancer concurrently. The biological and clinical features of these two patients were very similar to each other; they both developed SLL with trisomy 12 and lacked lymphocytosis or cytopenia. SLL cells involved nodal areas adjacent to lung adenocarcinoma which expressed PD-L1. One patient received immunochemotherapy including nivolumab and ipilimumab against lung cancer, and notably, transient deterioration of SLL occurred after the second cycle of immunochemotherapy along with the development of immune related adverse events. Immunohistochemical analysis of the SLL samples of the patient revealed that the tumor cells were positive for CTLA-4, suggesting that ipilimumab might have potentially induced the activation of SLL cells by blocking the inhibitory signal mediated by CTLA-4. These clinical findings indicate the potential biological relationship between SLL and lung cancer. According to these observations, we would like to draw attention to the possibility of deterioration of SLL when immune checkpoint inhibitors are used for the treatment of malignancies developed in SLL patients.

Differential analysis of immune reconstitution after allogeneic hematopoietic stem cell transplantation in children with Wiskott-Aldrich syndrome and chronic granulomatous disease

Objective

To investigate similarities and differences in immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with Wiskott-Aldrich syndrome (WAS) and chronic granulomatous disease (CGD).

Method

We retrospectively analyzed the lymphocyte subpopulations and the serum level of various immune-related protein or peptide on Days 15, 30, 100, 180 and 360 post-transplantation in 70 children with WAS and 48 children with CGD who underwent allo-HSCT at the Transplantation Center of the Department of Hematology-Oncology, Children's Hospital of Chongqing Medical University from January 2007 to December 2020, and we analyzed the differences in the immune reconstitution process between the two groups.

Results

① The WAS group had higher lymphocyte subpopulation counts than the CGD group. ② Among children aged 1-3 years who underwent transplantation, the WAS group had higher lymphocyte subpopulation counts than the CGD group. ③ Further comparisons were performed between children with non-umbilical cord blood transplantation (non-UCBT) and children with umbilical cord blood transplantation (UCBT) in the WAS group. On Day 15 and 30 post-transplantation, the non-UCBT group had higher B-cell counts than the UCBT group. On the remaining time points post-transplantation, the UCBT group had higher lymphocyte subpopulation counts than the non-UCBT group. ④ Comparisons were performed between children with non-UCBT in the WAS group and in the CGD group, the lymphocyte subpopulation counts were higher in the WAS group compared to the CGD group. ⑤ On Day 100 post-transplantation, the CGD group had higher C3 levels than the WAS group. On Day 360 post-transplantation, the CGD group had higher IgA and C4 levels than the WAS group.

Conclusion

① The rate of immunity recovery was faster in children within the WAS group compared to those children within the CGD group, which may be attributed to the difference of percentage undergoing UCBT and primary diseases. ② In the WAS group, the non-UCBT group had higher B-cell counts than the UCBT group at Day 15 and 30 post-transplantation, however, the UCBT group had higher B-cell counts than the non-UCBT group at Day 100 and 180 post-transplantation, suggesting that cord blood has strong B-cell reconstitution potentiality after transplantation.

Fibrotic Hypersensitivity Pneumonitis Diagnosed by a Re-evaluation with Bronchoalveolar Lavage at Disease Deterioration

A 79-year-old man was admitted with worsening cough, dyspnea, and increased ground-glass opacity on chest computed tomography (CT). He had been diagnosed with idiopathic pulmonary fibrosis given the absence of an identifiable cause of interstitial pneumonia, chest CT findings, and absence of lymphocytosis in bronchoalveolar lavage (BAL) fluid. Meticulous history taking revealed extensive exposure to inciting antigens contained in chicken fertilizer before symptom worsening. A re-evaluation with BAL showed lymphocytosis, and clinical improvement with antigen avoidance confirmed the diagnosis of fibrotic hypersensitivity pneumonitis (fHP). A re-evaluation with BAL at disease deterioration after possible exposure to inciting antigen can facilitate a correct fHP diagnosis.

Increased risk of incident diabetes after therapy with immune checkpoint inhibitor compared with conventional chemotherapy: A longitudinal trajectory analysis using a tertiary care hospital database

AIMS/HYPOTHESIS

Immune checkpoint inhibitor (ICI) has been emerged as a promising cancer treatment. However, ICI use induces immune-related adverse events, including diabetes mellitus. We compared the risk of new-onset diabetes between patients receiving an ICI and those receiving conventional chemotherapy (CC).

METHODS

Using a tertiary care hospital database, we included cancer patients without a previous history of diabetes who were treated with either CC or an ICI. One-to-five nearest neighbor propensity matching was applied, and the risk of diabetes was estimated using a Cox proportional hazards model. Latent class growth modeling was performed with a trajectory approach to determine distinct clusters that followed similar glucose trajectory patterns over time.

RESULTS

Among 1326 subjects, 1105 received CC, and 221 received an ICI. The risk of new-onset diabetes was significantly higher in the ICI group than the CC group (adjusted hazard ratio 2.454, 95 % confidence interval 1.528-3.940; p < 0.001). The ICI group had a higher proportion of subjects in the trajectory cluster with an increasing glucose pattern than the CC group (10.4 % and 7.4 %, respectively). Within the ICI group, the subjects with an increasing glucose pattern were predominantly male and associated with enhanced lymphocytosis after ICI administration.

CONCLUSIONS

ICI therapy is associated with an increased risk of incident diabetes compared with CC. The glucose levels of patients treated with an ICI, especially males and those with prominent lymphocytosis after ICI treatment, need to be monitored regularly to detect ICI-associated diabetes as early as possible.

Chronic lymphocytic leukemia: from molecular pathogenesis to novel therapeutic strategies

Chronic lymphocytic leukemia is a well-defined lymphoid neoplasm with very heterogeneous biological and clinical behavior. The last decade has been remarkably fruitful in novel findings elucidating multiple aspects of the pathogenesis of the disease including mechanisms of genetic susceptibility, insights into the relevance of immunogenetic factors driving the disease, profiling of genomic alterations, epigenetic subtypes, global epigenomic tumor cell reprogramming, modulation of tumor cell and microenvironment interactions, and dynamics of clonal evolution from early steps in monoclonal B cell lymphocytosis to progression and transformation into diffuse large B-cell lymphoma. All this knowledge has offered new perspectives that are being exploited therapeutically with novel target agents and management strategies. In this review we provide an overview of these novel advances and highlight questions and perspectives that need further progress to translate into the clinics the biological knowledge and improve the outcome of the patients.

The Clinical Characteristics and Outcomes of Patients with Moderate-to-Severe Coronavirus Disease 2019 Infection and Diabetes in Daegu, South Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global pandemic that had affected more than eight million people worldwide by June 2020. Given the importance of the presence of diabetes mellitus (DM) for host immunity, we retrospectively evaluated the clinical characteristics and outcomes of moderate-to-severe COVID-19 in patients with diabetes.

METHODS

We conducted a multi-center observational study of 1,082 adult inpatients (aged ≥18 years) who were admitted to one of five university hospitals in Daegu because of the severity of their COVID-19-related disease. The demographic, laboratory, and radiologic findings, and the mortality, prevalence of severe disease, and duration of quarantine were compared between patients with and without DM. In addition, 1:1 propensity score (PS)-matching was conducted with the DM group.

RESULTS

Compared with the non-DM group (n=847), patients with DM (n=235) were older, exhibited higher mortality, and required more intensive care. Even after PS-matching, patients with DM exhibited more severe disease, and DM remained a prognostic factor for higher mortality (hazard ratio, 2.40; 95% confidence interval, 1.38 to 4.15). Subgroup analysis revealed that the presence of DM was associated with higher mortality, especially in older people (≥70 years old). Prior use of a dipeptidyl peptidase-4 inhibitor or a renin-angiotensin system inhibitor did not affect mortality or the clinical severity of the disease.

CONCLUSION

DM is a significant risk factor for COVID-19 severity and mortality. Our findings imply that COVID-19 patients with DM, especially if elderly, require special attention and prompt intensive care.

Rheumatoid disease: an unusual cause of relapsing meningoencephalitis

A 73-year-old man presented with three episodes of dysphasia and disinhibited behaviour, a single seizure and transient ischaemic attack-like events characterised by right arm and/or leg weakness. These episodes were separated by month-long asymptomatic intervals. Medical history included rheumatoid arthritis, which was clinically quiescent on leflunomide.Repeated cerebrospinal fluid examination showed a persistent lymphocytosis with mildly reduced glucose and elevated protein; oligoclonal bands and viral PCR were negative. MRI of the brain was initially normal, but 7 months after initial presentation revealed meningeal enhancement with bifrontal cortical hyperintensities on T2/fluid-attenuated inversion recovery. Brain biopsy demonstrated necrotising granulomatous meningitis with mixed T cell and B cell infiltrates and without evidence of vasculitis or infection. Serum anticyclic citrullinated peptide antibodies were strongly positive.The diagnosis of rheumatoid meningoencephalitis was made on the basis of brain biopsy findings and serological evidence of active rheumatoid disease. Steroids and rituximab therapy were started leading to clinical stabilisation.

[Clinical analysis of 247 children with whooping cough and the risk factors of severe cases]

OBJECTIVE

To summarize the clinical characteristics of whooping cough in children and analyze the risk factors for severe whooping cough.

METHOD

A retrospective analysis was made on the clinical data of 247 children with whooping cough in Children's Hospital of Chongqing Medical University between Jan 2013 and Dec 2014. Of these patients, 126 were male, 121 were female, the median age was 3.1 months (23 days-4 years and eight months old). The patients were divided into two groups, group 1 had infants less than 3 months of age (n=120) and group 2 had infants and young children older than 3 months (n=127) according to their age. On the other hand, the patients were also divided into two groups according to vaccination status: vaccinated group (received diphtheria toxoid, tetanus toxoid, and acellular pertussis, DTP) (n=31) and unvaccinated group (n=188). Pure Bordetella pertussis infection was seen in 106 cases, and 141 cases had mixed infection. Severe disease was seen in 13 cases, and the other 234 cases had the modest disease. Clinical data were retrospectively analyzed and compared.

RESULT

(1) Bordetella pertussis was identified in 57/680 cases (8.4%) in 2013, and 190/1 856 cases (10.2%) in 2014. The disease could be seen throughout the year, but 182 cases (73.7%) occurred in summer or autumn; 202 cases (81.8%) were less than 6 months. (2) Paroxysmal cough was seen in 238 cases (96.4%) , 61 cases (24.7%) had inspiratory whoop. Infants in group 1 often had episodes of cyanosis, apnea and suffocation (χ² = 19.999, 12.081, 6.508, P<0.05), persistent cough was often seen in group 2 (χ² = 9.885, P<0.05). Complications such as severe pneumonia, pulmonary consolidation and encephalopathy were more common in the group 1 than in group 2 (χ² = 17.340, 6.080, 11.030, 23.545, P<0.05). (3) The length of stay of group 1, and of unvaccinated group was significantly longer than that of group 2 and of vaccinated group (t=19.331, 26.741, P<0.05). (4) Leukocytosis was found in 224 cases (90.7%), 182 cases (73.7%) had predominant lymphocytosis. White blood cell in group 1, unvaccinated group and severe disease group was higher than the corresponding group (t=11.075,13.739,3.469, P<0.05). (5) Patients who had a history of exposure, fever, leukocytosis and pulmonary consolidation or atelectasis on chest imaging were prone to develop into severe pertussis (OR=4.521, 4.900, 1.085, 4.792, 50.400; P<0.05). A total of 244 cases (98.8%) recovered, 3 cases (1.2%) died, they were less than 3 months old and unvaccinated.

CONCLUSION

The number of cases with whooping cough in Chongqing area tends to be rising. The disease occurred mostly in summer and fall. Infants less than 3 months old, unvaccinated with DTP had high susceptibility to pertussis, often had a severe clinical presentation and severe complications, had a high mortality rate.

[Case of tuberculous pleurisy distinguished from pleurisy caused by Mycoplasma infection]

We report a case of tuberculous pleurisy that required differentiation from pleurisy caused by Mycoplasma infection. A 28-year-old woman presented to a clinic with fever and pain on the left side of her chest. A chest radiograph revealed pleural effusion in the left thorax, and the condition was diagnosed as bacterial pleurisy. The patient was referred to our hospital because of an increase in the pleural effusion despite antibiotic treatment. Mycoplasma infection was suspected because the patient was young, the white blood cell count was not elevated, and the result of the ImmunoCard Mycoplasma test (IC) for Mycoplasma pneumoniae-specific IgM antibodies was positive. However, the fever persisted even after treatment with azithromycin and pazufloxacin. The left pleural effusion was exudative, with lymphocytosis and high adenosine deaminase (ADA) levels. The results of the QuantiFERON test were positive. Therefore, tuberculous pleurisy was diagnosed, and the effusion subsided after treatment with standard anti-tuberculosis chemotherapy. Although detection of Mycoplasma infection using the IC is rapid and simple, the accuracy of this test is poor. The patient was first diagnosed with pleurisy of Mycoplasma origin because of a single high-particle agglutination titer of 1: 320 and because of the presence of exudative pleural effusion with lymphocytosis and elevated ADA levels, which has been reported in patients with Mycoplasma infection. The results of the IC test and the ADA level of the pleural effusion might not be reliable when distinguishing between tuberculous pleurisy and pleurisy caused by Mycoplasma infection.

Dominant cross-reactive B cell response during secondary acute dengue virus infection in humans

The four serotypes of dengue virus (DENV) cause dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Severe disease has been associated with heterotypic secondary DENV infection, mediated by cross-reactive antibodies (Abs) and/or cross-reactive T cells. The role of cross-reactive immunity in mediating enhanced disease versus cross-protection against secondary heterotypic DENV infection is not well defined. A better understanding of the cross-reactive immune response in natural infections is critical for development of safe and effective tetravalent vaccines. We studied the B cell phenotype of circulating B cells in the blood of pediatric patients suspected of dengue during the 2010–2011 dengue season in Managua, Nicaragua (n = 216), which was dominated by the DENV-3 serotype. We found a markedly larger percentage of plasmablast/plasma cells (PB/PCs) circulating in DENV-positive patients as compared to patients with Other Febrile Illnesses (OFIs). The percentage of DENV-specific PB/PCs against DENV-3 represented 10% of the circulating antibody-producing cells (ASCs) in secondary DENV-3 infections. Importantly, the cross-reactive DENV-specific B cell response was higher against a heterotypic serotype, with 46% of circulating PB/PCs specific to DENV-2 and 10% specific to DENV-3 during acute infection. We also observed a higher cross-reactive DENV-specific IgG serum avidity directed against DENV-2 as compared to DENV-3 during acute infection. The neutralization capacity of the serum was broadly cross-reactive against the four DENV serotypes both during the acute phase and at 3 months post-onset of symptoms. Overall, the cross-reactive B cell immune response dominates during secondary DENV infections in humans. These results reflect our recent findings in a mouse model of DENV cross-protection. In addition, this study enabled the development of increased technical and research capacity of Nicaraguan scientists and the implementation of several new immunological assays in the field.

Dengue is the most common mosquito-borne viral infection of humans, with half the world's population at risk for infection. Four different dengue virus serotypes (DENV-1 to -4) can cause the disease, which can be either inapparent or present with flu-like symptoms (Dengue Fever), also known as “breakbone fever”. In a number of cases, the disease can be more severe and sometimes fatal, with signs of bleeding and vascular leakage leading to shock (Dengue Hemorrhagic Fever/Dengue Shock Syndrome). Severe disease has been associated with secondary sequential DENV infections, i.e., infection with a second DENV serotype different from the serotype causing the first infection. No specific treatment or vaccine is available. Understanding how the human immune response develops during a natural infection can be beneficial for future vaccine studies and trials. B cells are a subset of cells that produce antibodies and are thus essential in the response to natural infections and vaccines. We show here that during secondary DENV infections in humans, the B cell immune response to a previous infecting DENV serotype is stronger than the response against the current infecting serotype. In addition, this study allowed the development of research capacity and implementation of new immunological assays in Nicaragua.

[Clinicopathologic features of aggressive natural killer cell leukemia]

OBJECTIVE

To study the clinicopathologic features of aggressive natural killer cell leukemia (ANKL).

METHODS

The clinical and pathologic features were analyzed in 10 patients with ANKL. The complete blood count, peripheral blood smears, bone marrow aspirates and bone marrow biopsies were studied. Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry. T-cell receptor (TCR) γ gene rearrangement was studied by PCR method.

RESULTS

The most frequent hematologic abnormalities observed were anemia (7 cases) and thrombocytopenia (9 cases). Large granular lymphocytes were found on peripheral blood smears of 6 patients. In bone marrow aspirates, lymphocytosis (> 20.0%) was demonstrated in 8 cases and large granular lymphocytes in 6 cases. Bone marrow biopsies revealed various degrees of neoplastic infiltration, as follows: mild (5 cases), moderate (3 cases) and severe (2 cases). The neoplastic cells were mainly interstitial in distribution in 8 cases and diffuse in 2 cases. Hemophagocytosis was observed in 4 cases. Flow cytometry showed CD2+ sCD3- CD4- CD56+ CD57- in all cases, CD7+ in 9 cases, CD16+ in 5 cases, CD8+ in 4 cases and CD5+ in 1 case. Immunohistochemistry performed in 8 cases showed the following results: cCD3+ in 4 cases, CD56+ in 6 cases, TIA-1+ in 6 cases, granzyme B+ in 4 cases and perforin+ in 2 cases. PCR study revealed germline TCRγ gene configuration in all cases.

CONCLUSIONS

ANKL is a highly aggressive NK cell-derived lymphoid neoplasm. Comprehensive morphologic, immunophenotypic and molecular analysis are essential in arriving at a correct diagnosis. ANKL needs to be distinguished from other types of NK-cell and T-cell lymphomas.

Role of omalizumab in a patient with hyper-IgE syndrome and review dermatologic manifestations

Hyper-IgE syndrome (HIES) is a rare idiopathic primary immunodeficiency. It is characterized by a triad of findings, including high levels of serum IgE, recurrent skin abscesses and pneumonia and leads to pneumatocele formation. The diagnosis of HIES is complicated by a diversity of clinical and immunological spectrums and a heterogeneous set of genetic defects. The National Institute of Health (NIH) developed a scoring system for HIES in which a score greater than 14 indicates a probable diagnosis. Our patient presented with recurrent multiple abscesses on her scalp, recalcitrant eczema, candida onychomycosis, alopecia universalis, and highly elevated levels of serum IgE. Using the NIH scoring system, a 30 total-point score in this patient indicated the likelihood of carrying the HIES genotype. To our knowledge, there are no specific treatments of HIES. The humanized recombinant monoclonal antibody against IgE, subcutaneous omalizumab, was successfully used in this patient.

A Pilot Trial of Rituximab and Alemtuzumab Combination Therapy in Patients with Relapsed and/or Refractory Chronic Lymphocytic Leukemia (CLL)

The treatment of patients with chronic lymphocytic leukemia (CLL) who fail purine analogues is sub optimal. CLL lymphocytes express two antigens, namely CD 20 and CD 52, for which monoclonal antibodies are readily available. Rituximab is a chimeric monoclonal antibody targeted against CD 20, which has some activity in refractory CLL, with primary effect on nodal disease. Alemtuzumab is a humanized anti-CD 52 antibody that is approved for the treatment of CLL in patients who fail alkylating agents and purine analogues. Alemtuzumab has better activity in the peripheral blood and the bone marrow compared to nodal disease. We investigated whether combining both antibodies is safe in refractory CLL. Both antibodies were given to a total of 12 patients divided into 3 cohorts with escalating alemtuzumab doses (3 mg, 10 mg, and 30 mg). The combination was proven to be safe, not toxic, feasible, and active. One patient attained PR by NCI criteria while all other patients had stable disease lasting a median of 101.5 days. All patients normalized their peripheral lymphocytosis within a median of 23.5 days. No treatment-related mortality was identified. No CMV reactivation occurred. Additional studies are needed to investigate the clinical significance of such a combination in this patient population, and whether this combination can be administered safely with systemic chemotherapy. These studies are currently underway.