Ahmed Naqvi

Comparison of primary human cytotoxic T-cell and natural killer cell responses reveal similar molecular requirements for lytic granule exocytosis but differences in cytokine production.

Cytotoxic lymphocytes, encompassing cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, kill pathogen-infected, neoplastic, or certain hematopoietic cells through the release of perforin-containing lytic granules. In the present study, we first performed probability-state modeling of differentiation and lytic granule markers on CD8(+) T cells to enable the comparison of bona fide CTLs with NK cells. Analysis identified CD57(bright) expression as a reliable phenotype of granule marker-containing CTLs. We then compared CD3(+)CD8(+)CD57(bright) CTLs with NK cells. Healthy adult peripheral blood CD3(+)CD8(+)CD57(bright) CTLs expressed more granzyme B but less perforin than CD3(-)CD56(dim) NK cells. On stimulation, such CTLs degranulated more readily than other T-cell subsets, but had a propensity to degranulate that was similar to NK cells. Remarkably, the CTLs produced cytokines more rapidly and with greater frequency than NK cells. In patients with biallelic mutations in UNC13D, STX11, or STXBP2 associated with familial hemophagocytic lymphohistiocytosis, CTL and NK cell degranulation were similarly impaired. Therefore, cytotoxic lymphocyte subsets have similar requirements for Munc13-4, syntaxin-11, and Munc18-2 in lytic granule exocytosis. The present results provide a detailed comparison of human CD3(+)CD8(+)CD57(bright) CTLs and NK cells and suggest that analysis of CD57(bright) CTL function may prove useful in the diagnosis of primary immunodeficiencies including familial hemophagocytic lymphohistiocytosis.

A mixed method approach to describe the out-of-pocket expenses incurred by families of children with cancer.

Families of children with cancer are confronted with a broad range of direct costs (out‐of‐pocket expenses), but the nature of these costs is poorly understood. This study aimed to disaggregate and describe these costs.

A prospective study to determine the costs incurred by families of children newly diagnosed with cancer in Ontario

A diagnosis of cancer in childhood places a considerable economic burden on families, although costs are not well described. The objectives of this study were to identify and determine independent predictors of the direct and time costs incurred by such families.

Sweet syndrome developing during treatment with all-trans retinoic acid in a child with acute myelogenous leukemia.

Acute febrile neutrophilic dermatosis (Sweet syndrome) has been reported in a few adults receiving all-trans retinoic acid for acute promyelocytic leukemia. The authors report a case of Sweet syndrome associated with the administration of all-trans retinoic acid for acute promyelocytic leukemia in a pediatric patient.

Reliability and construct validity of the oral mucositis daily questionnaire in children with cancer

BACKGROUND The objective of this study was to examine the test-retest reliability and construct validity of parent-reported Oral Mucositis Daily Questionnaire (OMDQ) in children receiving intensive chemotherapy. METHODS Parents of children with cancer receiving intensive chemotherapy for leukaemia/lymphoma or undergoing stem cell transplantation (SCT) were asked to complete OMDQ daily for 21 d after chemotherapy. Other measures of mucositis obtained concurrently with OMDQ included the World Health Organization (WHO) Mucositis Scale, pain Visual Analogue Scale (VAS) and the Functional Assessment of Cancer Therapy Esophageal Cancer Sub-scale (FACT-ECS). RESULTS Parents of 59 children (median age = 5.62) provided complete OMDQ data for inclusion in analysis. The majority of children (73%) received SCT. Test-retest reliability of OMDQ exceeded the expected moderate reliability threshold established a priori and in particular, was good to excellent when mucositis was expected. In general, items of OMDQ that relate to pain, swallowing, drinking, eating and talking demonstrated moderate correlations with WHO, VAS and FACT-ECS indices with correlation coefficients ≥ 0.5. CONCLUSIONS Parent-report of a modified version of OMDQ is reliable and the questions relating to mouth and throat pain, as well as effect on function display construct validity for this population of children receiving intensive chemotherapy.

Determining the Understandability and Acceptability of an Oral Mucositis Daily Questionnaire

Oral mucositis research in children receiving anticancer therapy has been impeded by the lack of an acceptable, appropriate assessment scale. Some scales attempt to measure subjective symptoms associated with mucositis such as pain and difficulty swallowing. These types of patient-reported outcomes are gaining prominence in clinical trials because they capture the perspective of the patients in whom the intervention is designed to benefit. In mucositis research, very few patient-reported outcome measures have been developed. The aim of this study was to determine whether an adaptation of the adult-validated Oral Mucositis Daily Questionnaire is understandable and acceptable for use in the pediatric oncology/hematology population. Twelve subjects were asked to rate their opinion of understandability and acceptability of the adapted Oral Mucositis Daily Questionnaire. As a result of their comments, minor changes were made. Evaluation of the psychometric properties of this instrument can now be performed.

An N-Terminal Missense Mutation in STX11 Causative of FHL4 Abrogates Syntaxin-11 Binding to Munc18-2.

Familial hemophagocytic lymphohistiocytosis (FHL) is an often-fatal hyperinflammatory disorder caused by autosomal recessive mutations in PRF1, UNC13D, STX11, and STXBP2. We identified a homozygous STX11 mutation, c.173T > C (p.L58P), in three patients presenting clinically with hemophagocytic lymphohistiocytosis from unrelated Pakistani families. The mutation yields an amino acid substitution in the N-terminal Habc domain of syntaxin-11 and resulted in defective natural killer cell degranulation. Notably, syntaxin-11 expression was decreased in patient cells. However, in an ectopic expression system, syntaxin-11 L58P was expressed at levels comparable to wild-type syntaxin-11, but did not bind Munc18-2. Moreover, another N-terminal syntaxin-11 mutant, R4A, also did not bind Munc18-2. Thus, we have identified a novel missense STX11 mutation causative of FHL type 4. The syntaxin-11 R4A and L58P mutations reveal that both the N-terminus and Habc domain of syntaxin-11 are required for binding to Munc18-2, implying similarity to the dynamic binary binding of neuronal syntaxin-1 to Munc18-1.

Efficacy and safety of caspofungin for the empiric management of fever in neutropenic children.

This retrospective review evaluates the response to caspofungin when given to children with febrile neutropenia and describes adverse effects attributable to caspofungin, including risk of hepatotoxicity during concomitant therapy with cyclosporine. Sixty-seven courses of caspofungin administered to 56 patients (1–17 years) were surveyed; 53 (79%) courses resulted in an overall favorable response. Ten children (15% of courses) experienced an adverse drug-related event that was probably or possibly attributable to caspofungin. Rash and hypokalemia were the most commonly identified adverse effects. One of 19 children receiving caspofungin and cyclosporine concurrently developed hepatotoxicity possibly related to caspofungin.

How to Treat Involvement of the Central Nervous System in Hemophagocytic Lymphohistiocytosis

Opinion statementCentral nervous system (CNS)-hemophagocytic lymphohistiocytosis (HLH) is not a disease in itself, but it is part of a systemic immune response. The vast majority of patients with CNS-HLH also have systemic HLH and a large number of patients with primary and secondary HLH have CNS involvement. Reactivations within the CNS are frequent during the course of HLH treatment and may occur concomitant with or independent of systemic relapses. It is also important to consider primary HLH as an underlying cause of “unknown CNS inflammation” as these patients may present with only CNS disease. To initiate proper treatment, a correct diagnosis must be made. A careful review of the patient’s history and a thorough neurological examination are essential. In addition to the blood tests required to make a diagnosis of HLH, a lumbar puncture with cerebrospinal fluid (CSF) analysis and magnetic resonance imaging (MRI) should always be done in all cases regardless of the presence or absence of neurological signs or symptom. Treatment options for CNS-HLH include, but are not limited to, those commonly used in systemic HLH, including corticosteroids, etoposide, cyclosporine A, alemtuzumab, and ATG. In addition, intrathecal treatment with methotrexate and corticosteroids has become a standard care and is likely to be beneficial. Therapy must be initiated without inappropriate delay to prevent late effects in HLH. An interesting novel approach is an anti-IFN-gamma antibody (NI-0501), which is currently being tested. Hematopoietic stem cell transplantation (HSCT) also represents an important CNS-HLH treatment; patients with primary HLH may benefit from immediate HSCT even if there is active disease at time of transplantation, though care should be taken to monitor CNS inflammation through HSCT and treat if needed. Since CNS-HLH is a condition leading to the most severe late effects of HLH, early expert consultation is recommended.

Early Complications of Hyperleukocytosis and Leukapheresis in Childhood Acute Leukemias.

Hyperleukocytosis in children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) is associated with early morbidity and mortality. The benefit from leukapheresis is controversial, and its complications are not well defined. We analyzed the frequency of early complications in children with ALL and AML presenting with white blood cell (WBC) count >100×109/L, and the type and frequency of complications related to leukapheresis. During a 12-year period, 84 of 634 (13%) ALL and 18 of 143 (12.5%) AML patients presented with hyperleukocytosis. Leukapheresis was performed in 18 ALL and 12 AML patients. The median initial WBC was 474×109/L in the leukapheresis group compared with 175×109/L in the nonleukapheresis group. Neurological leukostasis occurred in 6 ALL (7.1%) and 4 AML (22.2%) patients. Pulmonary leukostasis occurred in 16 ALL (19%) and 4 AML patients (22.2%). Neurological symptoms improved in few patients after leukapheresis, except in patients with very high WBC (>650×109/L in ALL and >400×109/L in AML). Leukapheresis improved respiratory symptoms in some patients but caused worsening symptoms in others. Early death was associated with neurological complications, AML diagnosis, and coagulopathy. Leukapheresis did not delay initiation of chemotherapy, nor did it impact early response to chemotherapy or long-term survival. Complications included femoral vein thrombosis, electrolyte imbalances, and hemodynamic instability, which were all reversible. The role of leukapheresis as a cytoreductive procedure in childhood hyperleukocytic leukemia remains to be well defined.