Production and persistence of specific antibodies in COVID-19 patients with hematologic malignancies: role of rituximab.

The ability of patients with hematologic malignancies (HM) to develop an effective humoral immune response after COVID-19 is unknown. A prospective study was performed to monitor the immune response to SARS-CoV-2 of patients with follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), chronic lymphoproliferative disorders (CLD), multiple myeloma (MM), or myelodysplastic/myeloproliferative syndromes (MDS/MPN). Antibody (Ab) levels to the SARS-CoV-2 nucleocapsid (N) and spike (S) protein were measured at +1, +3, +6 months after nasal swabs became PCR-negative. Forty-five patients (9 FL, 8 DLBCL, 8 CLD, 10 MM, 10 MDS/MPS) and 18 controls were studied. Mean anti-N and anti-S-Ab levels were similar between HM patients and controls, and shared the same behavior, with anti-N Ab levels declining at +6 months and anti-S-Ab remaining stable. Seroconversion rates were lower in HM patients than in controls. In lymphoma patients mean Ab levels and seroconversion rates were lower than in other HM patients, primarily because all nine patients who had received rituximab within 6 months before COVID-19 failed to produce anti-N and anti-S-Ab. Only one patient requiring hematological treatment after COVID-19 lost seropositivity after 6 months. No reinfections were observed. These results may inform vaccination policies and clinical management of HM patients.

Use of a novel virus detection assay to identify coronavirus HKU1 in the lungs of a hematopoietic stem cell transplant recipient with fatal pneumonia.

A 38-year-old female patient with systemic lupus erythematosus presented with pulmonary infiltrates and hypoxemia for several months following immunodepleting autologous hematopoietic stem cell transplantation. She was treated for influenza, which was isolated repeatedly from oropharynx and bronchoalveolar lavage (BAL) fluids, and later empirically for lupus pneumonitis, but died 6 months after transplant. Autopsy findings failed to show influenza in the lungs or lupus pneumonitis. A novel generic polymerase chain reaction (PCR)-based assay using degenerate primers identified human coronavirus (CoV) HKU1 RNA in BAL fluid at autopsy. CoV was confirmed by virus-specific PCRs of lung tissue at autopsy. Electron microscopy showed viral particles consistent with CoV HKU1 in lung tissue both at autopsy and from a previous biopsy. Although human CoV HKU1 infection is not usually severe, in highly immunocompromised patients, it can be associated with fatal pneumonia.

Abnormal Cholesterol is Associated with Prefrontal White Matter Abnormalities among Obese Adults: a Diffusion Tensor Imaging Study.

The brain is the most cholesterol-rich organ in the body. Although most of the cholesterol in the brain is produced endogenously, some studies suggest that systemic cholesterol may be able to enter the brain. We investigated whether abnormal cholesterol profiles correlated with diffusion-tensor-imaging-based estimates of white matter microstructural integrity of lean and overweight/obese (o/o) adults. Twenty-two lean and 39 obese adults underwent magnetic resonance imaging, kept a three-day food diary, and had a standardized assessment of fasting blood lipids. The lean group ate less cholesterol-rich food than o/o although both groups ate equivalent servings of food per day. Voxelwise correlational analyses controlling for age, diabetes, and white matter hyperintensities, resulted in two significant clusters of negative associations between abnormal cholesterol profile and fractional anisotropy, located in the left and right prefrontal lobes. When the groups were split, the lean subjects showed no associations, whereas the o/o group expanded the association to three significant clusters, still in the frontal lobes. These findings suggest that cholesterol profile abnormalities may explain some of the reductions in white matter microstructural integrity that are reported in obesity.

Update on new antivirals under development for the treatment of double-stranded DNA virus infections.

All the currently available antiviral agents used in the treatment of double-stranded (ds) DNA viruses, with the exception of interferon-α, inhibit the same target, the viral DNA polymerase. With increasing reports of the development of resistance of herpes simplex virus (HSV), cytomegalovirus (CMV), and hepatitis B virus (HBV) to some of these drugs, new antiviral agents are needed to treat these infections. Additionally, no drugs have been approved to treat several DNA virus infections, including those caused by adenovirus, smallpox, molluscum contagiosum, and BK virus. We report the status of 10 new antiviral drugs for the treatment of dsDNA viruses. CMX-001 has broad activity against dsDNA viruses; 3 helicase-primase inhibitors, maribavir, and FV-100 have activity against certain herpesviruses; ST-246 inhibits poxviruses; GS-9191 inhibits papillomaviruses; and clevudine and emtricitabine are active against HBV. Most of these drugs have completed at least phase I trials in humans, and many are in additional clinical trials.

Epstein-Barr virus-associated lymphoproliferative disease in non-immunocompromised hosts: a status report and summary of an international meeting, 8-9 September 2008.

BACKGROUND: Recently novel Epstein-Barr virus (EBV) lymphoproliferative diseases (LPDs) have been identified in non-immunocompromised hosts, both in Asia and Western countries. These include aggressive T-cell and NK-cell LPDs often subsumed under the heading of chronic active Epstein-Barr virus (CAEBV) infection and EBV-driven B-cell LPDs mainly affecting the elderly. DESIGN: To better define the pathogenesis, classification, and treatment of these disorders, participants from Asia, The Americas, Europe, and Australia presented clinical and experimental data at an international meeting. RESULTS: The term systemic EBV-positive T-cell LPD, as adopted by the WHO classification, is preferred as a pathological classification over CAEBV (the favored clinical term) for those cases that are clonal. The disease has an aggressive clinical course, but may arise in the background of CAEBV. Hydroa vacciniforme (HV) and HV-like lymphoma represent a spectrum of clonal EBV-positive T-cell LPDs, which have a more protracted clinical course; spontaneous regression may occur in adult life. Severe mosquito bite allergy is a related syndrome usually of NK cell origin. Immune senescence in the elderly is associated with both reactive and neoplastic EBV-driven LPDs, including EBV-positive diffuse large B-cell lymphomas. CONCLUSION: The participants proposed an international consortium to facilitate further clinical and biological studies of novel EBV-driven LPDs.

HMG CoA reductase inhibitors (statins) to treat Epstein-Barr virus-driven lymphoma.

While statins have been highly effective for lowering serum cholesterol and reducing the incidence of coronary events, they have multiple other effects. Certain statins block the interaction of adhesion molecules that are important for cell-cell interactions including those between EBV-transformed B cells. These same statins inhibit NF-kappaB activation in the cells and induce apoptosis of transformed B cells. Studies in severe combined immunodeficiency mice show that simvastatin delays the development of EBV-lymphomas in these animals. These statins might be considered for the treatment of EBV-lymphomas in selected patients.

LMO2-associated clonal T cell proliferation in two patients after gene therapy for SCID-X1.

We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.

Activation of NK cell-mediated cytotoxicity by a SAP-independent receptor of the CD2 family.

Some CD2 family receptors stimulate NK cell-mediated cytotoxicity through a signaling pathway, which is dependent on the recruitment of an adapter protein called SLAM-associated protein (SAP). In this work we identify a novel leukocyte cell surface receptor of the CD2 family called CD2-like receptor activating cytotoxic cells (CRACC). CRACC is expressed on cytotoxic lymphocytes, activated B cells, and mature dendritic cells, and activates NK cell-mediated cytotoxicity. Remarkably, although CRACC displays cytoplasmic motifs similar to those recruiting SAP, CRACC-mediated cytotoxicity occurs in the absence of SAP and requires activation of extracellular signal-regulated kinases-1/2. Thus, CRACC is a unique CD2-like receptor which mediates NK cell activation through a SAP-independent extracellular signal-regulated kinase-mediated pathway.

Infection with Langat Flavivirus or expression of the envelope protein induces apoptotic cell death.

Langat (LGT) flavivirus, derived from infectious full-length cDNA clone 636, was investigated for its apoptotic activities in mouse neuroblastoma (Neuro-2a) and simian kidney (Vero and LLC-MK(2)) cells. The hallmark of apoptosis, cleavage of cellular DNA, was observed 48 h after infection of Vero, LLC-MK(2), and Neuro-2a cells by electrophoresis analysis. Apoptosis in infected cells was also confirmed by TUNEL assay. LGT-infected Neuro-2a cells showed an increase in caspase-3-like protease (DEVDase) activity. Expression of the major envelope glycoprotein (E) alone reduced cell viability in both Vero and Neuro-2a cells, and the baculovirus P35 protein, which inhibits multiple caspases, completely blocked this effect. Cleavage of cellular DNA was observed in E gene-transfected Vero cells by TUNEL assay. Expression of E protein or caspase-9 resulted in activation of caspase-3-like proteases in Neuro-2a cells. The caspase-3-like protease specific inhibitor, Ac-DEVD-CHO peptide, partially inhibited E protein- or caspase-9-induced apoptosis in Neuro-2a cells. These observations indicate that infection of cells with LGT virus or expression of LGT virus E protein induces apoptosis through a caspase-3-like protease pathway.

Use of the radial forearm free tissue flap to treat persistent stricture after esophagogastrectomy.

BACKGROUND: Persistent stricturing or anastomotic leakage at the cervical esophagogastric anastomosis can be a troublesome complication of gastric pull-up procedures. When the stricture is the result of ischemia of the stomach, the strictures are long and often not responsive to dilatation and require large operations such as jejunal interposition or replacement with colonic pull-up. In this report we describe the use of a radial forearm flap to patch strictures. METHODS: The radial forearm flap is a fascia cutaneous flap taken from the forearm and based on the radial artery and its venae comitantes. The advantages of this flap are that it is thin and pliable, conforms easily, has excellent reliability due to the size of the feeding vessels, and has a relatively long pedicle. The vascular anastomosis can be made to several arteries and veins within the neck. The epithelial component can be made in sizes up to 10 by 20 cm. RESULTS: We have used the radial forearm flap to patch strictures in 6 patients with persistent complex strictures in the cervical region after esophagectomy. Results were excellent in 4 patients (able to eat liquids and solids without problems) and good in 1 patient (liquids okay, some problem with solids), and 1 patient died postoperatively. Follow-up is 4 months to 7 years. CONCLUSIONS: The radial forearm flap is an excellent option for handling persistent stricture after esophagogastrectomy. In many instances, this flap can be used in lieu of a jejunal interposition flap and obviates a laparotomy to harvest jejunum. The flap fits easily into the neck and conforms to the space.

Tracheoesophageal puncture in the office setting with local anesthesia.

Tracheoesophageal puncture (TEP) with voice prosthesis placement is currently the method of choice for vocal rehabilitation of patients who have undergone total laryngectomy. Occasionally, secondary TEP needs to be performed. We have used a TEP technique that is performed in the clinic setting with local anesthesia and no sedation. The purpose of this study was to review our technique and experience and to evaluate results, complications, and patients' acceptance of the procedure. We performed a retrospective chart review of the records of 14 patients who had undergone total laryngectomy and secondary TEP placement in the clinic setting. The procedure was well tolerated. The voice results were fair to good in 11 of 12 patients. There was 1 complication, a false passage between the trachea and the esophagus. Voicing was immediate in 12 of the 14 cases. We conclude that TEP can be performed in the office setting with local anesthesia. The voice results are excellent, and the procedure is well tolerated by the patient. Proper patient selection and regular follow-up by a speech-language pathologist are important.

Distinct interactions of the X-linked lymphoproliferative syndrome gene product SAP with cytoplasmic domains of members of the CD2 receptor family.

X-linked lymphoproliferative syndrome (XLP; Duncan's disease) is a primary immunodeficiency disease that manifests as an inability to regulate the immune response to Epstein-Barr virus (EBV) infection. Here we examine the ability of the product of the gene defective in XLP, SAP (DSHP/SH2D1A), to associate with the cytoplasmic domains of several members of the CD2 subfamily of cell surface receptors, including SLAM, 2B4, and CD84. While recruitment of SAP to SLAM occurred in a phosphorylation-independent manner, SAP was found to bind preferentially to tyrosine-phosphorylated cytoplasmic domains within 2B4 and CD84. Missense or nonsense mutations in the SAP open reading frame were identified in five of seven clinically diagnosed XLP patients from different kindreds. Four of these variants retained the ability to bind to the cytoplasmic tails of SLAM and CD84. While ectopic expression of wild-type SAP was observed to block the binding of SHP-2 to SLAM, mutant SAP derivatives that retained the ability to bind SLAM did not inhibit recruitment of SHP-2 to SLAM. In contrast, SAP binding to CD84 had no effect on the ability of CD84 to recruit SHP-2, but instead displaced SHP-1 from the cytoplasmic tail of CD84. These results suggest that mutations in the gene encoding the XLP protein SAP lead to functional defects in the protein that include receptor binding and SHP-1 and SHP-2 displacement and that SAP utilizes different mechanisms to regulate signaling through the CD2 family of receptors.

Mutagenesis of the varicella-zoster virus genome: lessons learned.

The varicella-zoster virus (VZV) genome encodes at least 70 genes. We have developed a cosmid based system to inactivate individual viral genes or to insert foreign genes into the genome. We have shown that many VZV genes are not required for replication of the virus in cell culture. Several of these genes, including VZV ORF61, ORF47, and ORF10, have unexpected phenotypes in cell culture and differ from their homologs in the better studied herpes simplex virus (HSV). We have also used the Oka strain of VZV as a live virus vaccine vector. Guinea pigs vaccinated with recombinant VZV expressing HSV-2 glycoprotein D and challenged with HSV-2 have reduced severity of primary genital herpes and reduced mortality compared to animals receiving parental VZV. Recently we have inserted the human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) glycoprotein 160 genes into the Oka strain of VZV and have shown that these proteins are expressed in recombinant virus-infected cells. Thus, directed mutagenesis of the VZV genome is providing new insights into viral pathogenesis and may provide new candidate vaccines.

A prospective comparison of scalpel versus bipolar scissors in the elevation of radial forearm fasciocutaneous free flaps.

OBJECTIVES/HYPOTHESIS: The radial forearm fasciocutaneous free flap has become the workhorse for reconstruction of head and neck ablative defects. A location distal to the head and neck allows this flap to be elevated concurrent with the ablation. Most commonly, the flap is elevated under tourniquet control. This involves a primary ischemic insult with a certain amount of hemorrhage after the tourniquet is released. Bipolar scissors are a new method of dissection. They may allow for a speedier dissection with a concomitant decrease in ischemic time. Their hemostatic properties may control hemorrhage after use of the tourniquet. STUDY DESIGN: A prospective study of patients undergoing radial forearm free flaps over a 12-month period at a tertiary care referral center was undertaken. RESULTS: Forty patients were entered into the study, flaps were elevated with scalpel (20) and with bipolar scissors (20). Mean time under tourniquet was 39 minutes (range, 30-56 min) with scalpel compared with 27 minutes (range, 21-31 min) with bipolar scissors (P <.001). Total mean time of elevation (including control of hemostasis and pedicle dissection) for scalpel elevation was 50 minutes (range, 35-61 min) compared with 32 minutes (range, 20-41 min) for bipolar scissors elevation (P <.001). Mean blood loss was 46 mL (range, 15-110 mL) in the scalpel elevation group compared with 14 mL (range, 0-50 mL) in the bipolar scissors elevation group (P <.001). Complications at the donor site were equal between groups. CONCLUSIONS: Bipolar scissors are a safe, efficient method for elevating radial forearm free flaps.

Effect of anemia on the fasciocutaneous flap survival in a rat model.

OBJECTIVE/HYPOTHESIS: Ablative surgery for head and neck cancer that creates large composite defects often results in a significant decrease in the hematocrit level. These defects are best reconstructed with a microvascular free tissue transfer. Effect of the decreased hematocrit on microvascular flap survival is controversial. The purpose of this study was to assess the effect of isovolemic anemia on flap survival in a rat model. STUDY DESIGN: Prospective analysis. METHODS: Ninety rats were used (30 control and 60 experimental animals). Experimental animals were rendered anemic by blood draw and volume resuscitated with either a colloid (30 animals) or crystalloid (30 animals) solution. In all animals a ventral fasciocutaneous flap was raised. A vascular clamp was applied to the arteriovenous pedicle, and different ischemic times were allowed to elapse before clamp removal. Flap survival was assessed at 5 days. Probit analysis was performed for the three animal groups. RESULTS: A significantly increased probability of the flap survival was found in the anemic animals compared with the control group (P < or = .05). No difference was found between the colloid and crystalloid resuscitation groups. CONCLUSIONS: A decreased hematocrit level increases fasciocutaneous flap tolerance to ischemia and significantly increases the primary ischemic time in the ventral flap clamp model in rats. Fluid replacement with either crystalloid or colloid produces identical results.

Varicella-zoster virus (VZV) ORF65 virion protein is dispensable for replication in cell culture and is phosphorylated by casein kinase II, but not by the VZV protein kinases.

The unique short region of varicella zoster virus (VZV) encodes four genes. One of these, ORF65, is predicted to encode an 11-kDa protein. Antibody to ORF65 protein immunoprecipitated a 16-kDa protein from the membrane fraction of VZV-infected cells. ORF65 protein was shown to be phosphorylated by casein kinase II. The VZV ORF47 or ORF66 protein kinases were not required for phosphorylation of ORF65. VZV with a large deletion in ORF65 was constructed and was shown to be dispensable for replication of virus in cell culture. The herpes simplex virus homolog of VZV ORF65 has been reported to be located in the nucleus of infected cells and in virions as a tegument protein, whereas the pseudorabies virus homolog is located in the Golgi apparatus of infected cells and in virions as a type II membrane protein. The ORF65 protein localized to the Golgi apparatus in virus-infected cells and was located in virions, most likely as a type II membrane protein. Thus, VZV ORF65 more closely resembles its pseudorabies virus homolog in its localization in infected cells and virions.

MRI detection of cervical metastasis from differentiated thyroid carcinoma.

BACKGROUND: With the advent of the use of serum thyroglobulin as a marker for the recurrence of well-differentiated thyroid cancer (WDTC) after total thyroidectomy, clinicians are increasingly faced with the diagnostic dilemma of detecting the site of recurrence in thyroglobulin-positive patients with normal clinical examinations. The high protein content of this thyroglobulin may make it specifically detectable by magnetic resonance (MR) imaging. OBJECTIVE: To determine the ability of MR imaging to detect the presence of metastatic WDTC in cervical lymph nodes. STUDY DESIGN: Retrospective cohort. METHODS: Blinded review by two independent head and neck radiologists of 34 head and neck MR scans obtained from 26 patients with thyroid cancer (12 with primary disease and 14 with recurrent disease) all of whom subsequently underwent surgical removal of the lymph nodes considered at risk by imaging. RESULTS: The average overall percent sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MR imaging were 95%, 51%, 84%, 78%, and 83%, respectively. The concordance between the two radiologists was 69%. There was no overall difference in the ability of the MR scan to detect the presence of disease in the upper jugular, lower jugular, or paratracheal nodal stations. However, it was more useful for papillary carcinoma (PPV 86%, accuracy 85%) than for follicular carcinoma or the follicular variant of papillary carcinoma (PPV 63%, accuracy 67%). CONCLUSION: MR imaging is a sensitive and accurate technique for the detection of WDTC, particularly papillary carcinoma, metastatic to cervical lymph nodes. However, the lower specificity of this modality precludes its use as a screening tool.

Accuracy of computed tomography in determining the presence or absence of metastatic retropharyngeal adenopathy.

OBJECTIVE: To decide the accuracy of computed tomography in determining the presence or absence of metastatic retropharygeal adenopathy in patients with squamous cell carcinoma of the head and neck. DESIGN: A comparison of the results of retrospective blinded review of preoperative computed tomographic scans with the histologic findings of retropharyngeal node dissection at the time of surgery. SETTING: Academic tertiary care center. PATIENTS: Twenty-six patients with advanced stage squamous cell carcinoma of the head and neck. MAIN OUTCOME MEASURES: Computed tomographic findings and histologic results of retropharyngeal node dissection. RESULTS: The retropharyngeal nodes were pathologically positive for metastasis in 6 (23%) of the 26 patients. The radiologist (J.M.T.) correctly read the scan in 3 of 6 patients with histologically proved metastasis, and in 14 of 20 patients with histologic features negative for metastasis. The sensitivity of the radiologist reading was 50%, and the specificity was 70%. The positive predictive value was 33%, and the negative predictive value was 82%. CONCLUSION: The presence of retropharyngeal node metastasis cannot be determined by computed tomographic imaging alone. Arch Otolaryngol Head Neck Surg. 2000;126:1478-1481

Patients with X-linked lymphoproliferative disease have a defect in 2B4 receptor-mediated NK cell cytotoxicity.

Patients with the X-linked lymphoproliferative disorder (XLPD) are unable to control Epstein-Barr virus (EBV)-induced infections and lymphoproliferation. This disease is caused by a deficit of SAP, an adapter protein involved in the signal transduction of several cell surface receptors of the CD2 superfamily. One of these receptors, called 2B4, is expressed on NK cells, cytotoxic T cells and myeloid cells and activates NK cell cytotoxicity. Here we show that XLPD patients have a defect of 2B4 receptor-mediated NK cell cytotoxicity. This defect may contribute to the pathogenesis of XLPD by reducing NK cell lysis of EBV-infected B cells.