Rosamma DeCastro

Pulmonary Nontuberculous Mycobacterial Disease: Prospective Study of a Distinct Preexisting Syndrome

RATIONALE Pulmonary nontuberculous mycobacterial (PNTM) disease is increasing, but predisposing features have been elusive. OBJECTIVES To prospectively determine the morphotype, immunophenotype, and cystic fibrosis transmembrane conductance regulator genotype in a large cohort with PNTM. METHODS We prospectively enrolled 63 patients with PNTM infection, each of whom had computerized tomography, echocardiogram, pulmonary function, and flow cytometry of peripheral blood. In vitro cytokine production in response to mitogen, LPS, and cytokines was performed. Anthropometric measurements were compared with National Health and Nutrition Examination Survey (NHANES) age- and ethnicity-matched female control subjects extracted from the NHANES 2001-2002 dataset. MEASUREMENTS AND MAIN RESULTS Patients were 59.9 (+/-9.8 yr [SD]) old, and 5.4 (+/-7.9 yr) from diagnosis to enrollment. Patients were 95% female, 91% white, and 68% lifetime nonsmokers. A total of 46 were infected with Mycobacterium avium complex, M. xenopi, or M. kansasii; 17 were infected with rapidly growing mycobacteria. Female patients were significantly taller (164.7 vs. 161.0 cm; P < 0.001) and thinner (body mass index, 21.1 vs. 28.2; P < 0.001) than matched NHANES control subjects, and thinner (body mass index, 21.1 vs. 26.8; P = 0.002) than patients with disseminated nontuberculous mycobacterial infection. A total of 51% of patients had scoliosis, 11% pectus excavatum, and 9% mitral valve prolapse, all significantly more than reference populations. Stimulated cytokine production was similar to that of healthy control subjects, including the IFN-gamma/IL-12 pathway. CD4(+), CD8(+), B, and natural killer cell numbers were normal. A total of 36% of patients had mutations in the cystic fibrosis transmembrane conductance regulator gene. CONCLUSIONS Patients with PNTM infection are taller and leaner than control subjects, with high rates of scoliosis, pectus excavatum, mitral valve prolapse, and cystic fibrosis transmembrane conductance regulator mutations, but without recognized immune defects.

The CXCR4 antagonist plerixafor corrects panleukopenia in patients with WHIM syndrome

WHIM syndrome is a rare congenital immunodeficiency disorder characterized by warts, hypogammaglobulinemia, infections, and myelokathexis (neutropenia because of impaired egress from the BM); most patients also have severe panleukopenia. Because WHIM syndrome is caused by mutations in the chemokine receptor CXCR4 that result in increased agonist-dependent signaling, we hypothesized that the CXCR4 antagonist plerixafor (Mozobil [Genyzme Corporation], AMD3100), might be an effective treatment. To test this, we enrolled 3 unrelated adult patients with the most common WHIM mutation, CXCR4(R334X), in a phase 1 dose-escalation study. Plerixafor increased absolute lymphocyte, monocyte, and neutrophil counts in blood to normal without significant side effects in all 3 patients. Peak responses occurred at 3-12 hours after injection and waned by 24 hours after injection which tracked the drugs pharmacokinetics. All 3 cell types increased in a dose-dependent manner with the rank order of responsiveness absolute lymphocyte > monocyte > neutrophil. These data provide the first pharmacologic evidence that panleukopenia in WHIM syndrome is caused by CXCL12-CXCR4 signaling-dependent leukocyte sequestration, and support continued study of plerixafor as mechanism-based therapy in this disease. This study is registered at http://www.clinicaltrials.gov as NCT00967785.

A phase 1 clinical trial of long-term, low-dose treatment of WHIM syndrome with the CXCR4 antagonist plerixafor

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is a rare immunodeficiency disorder caused by gain-of-function mutations in the G protein-coupled chemokine receptor CXCR4. The CXCR4 antagonist plerixafor, which is approved by the US Food and Drug Administration (FDA) for stem cell mobilization in cancer and administered for that indication at 0.24 mg/kg, has been shown in short-term (1- to 2-week) phase 1 dose-escalation studies to correct neutropenia and other cytopenias in WHIM syndrome. However, long-term safety and long-term hematologic and clinical efficacy data are lacking. Here we report results from the first long-term clinical trial of plerixafor in any disease, in which 3 adults with WHIM syndrome self-injected 0.01 to 0.02 mg/kg (4% to 8% of the FDA-approved dose) subcutaneously twice daily for 6 months. Circulating leukocytes were durably increased throughout the trial in all patients, and this was associated with fewer infections and improvement in warts in combination with imiquimod; however, immunoglobulin levels and specific vaccine responses were not fully restored. No drug-associated side effects were observed. These results provide preliminary evidence for the safety and clinical efficacy of long-term, low-dose plerixafor in WHIM syndrome and support its continued study as mechanism-based therapy in this disease. The ClinicalTrials.gov identifier for this study is NCT00967785.

Geosmithia argillacea: An Emerging Cause of Invasive Mycosis in Human Chronic Granulomatous Disease

BACKGROUND Chronic granulomatous disease (CGD) is an inherited disorder of the nicotinamide adenine dinucleotide phosphate oxidase that leads to defective production of microbicidal superoxide and other oxidative radicals, resulting in increased susceptibility to invasive infections, especially those due to fungi. METHODS Geosmithia argillacea was identified from cultured isolates by genomic sequencing of the internal transcribed spacer region. Isolates previously identified as Paecilomyces variotii, a filamentous fungus closely resembling G. argillacea, were also examined. RESULTS We identified G. argillacea as the cause of invasive mycosis in 7 CGD patients. In 5 cases, the fungus had been previously identified morphologically as P. variotii. All patients had pulmonary lesions; 1 had disseminated lesions following inhalational pneumonia. Infections involved the chest wall and contiguous ribs in 2 patients and disseminated to the brain in 1 patient. Four patients with pneumonia underwent surgical intervention. All patients responded poorly to medical treatment, and 3 died. CONCLUSIONS We report the first cases of invasive mycosis caused by G. argillacea in CGD patients. G. argillacea infections in CGD are often refractory and severe with a high fatality rate. Surgical intervention has been effective in some cases. G. argillacea is a previously underappreciated and frequently misidentified pathogen in CGD that should be excluded when P. variotii is identified morphologically.

WHIM syndrome caused by a single amino acid substitution in the carboxy-tail of chemokine receptor CXCR4

WHIM syndrome is a rare, autosomal dominant, immunodeficiency disorder so-named because it is characterized by warts, hypogammaglobulinemia, infections, and myelokathexis (defective neutrophil egress from the BM). Gain-of-function mutations that truncate the C-terminus of the chemokine receptor CXCR4 by 10-19 amino acids cause WHIM syndrome. We have identified a family with autosomal dominant inheritance of WHIM syndrome that is caused by a missense mutation in CXCR4, E343K (1027G → A). This mutation is also located in the C-terminal domain, a region responsible for negative regulation of the receptor. Accordingly, like CXCR4(R334X), the most common truncation mutation in WHIM syndrome, CXCR4(E343K) mediated approximately 2-fold increased signaling in calcium flux and chemotaxis assays relative to wild-type CXCR4; however, CXCR4(E343K) had a reduced effect on blocking normal receptor down-regulation from the cell surface. Therefore, in addition to truncating mutations in the C-terminal domain of CXCR4, WHIM syndrome may be caused by a single charge-changing amino acid substitution in this domain, E343K, that results in increased receptor signaling.

Risks of first and subsequent cancers among TP53 mutation carriers in the National Cancer Institute Li-Fraumeni syndrome cohort.

Li‐Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition syndrome characterized by a very high lifetime cancer risk and an early age at diagnosis of a wide cancer spectrum. Precise estimates for the risk of first and subsequent cancers are lacking.

AMD3100 is a Potent Antagonist at CXCR4R334X, a Hyperfunctional Mutant Chemokine Receptor and Cause of WHIM Syndrome

WHIM is an acronym for a rare immunodeficiency syndrome (OMIM #193670) caused by autosomal dominant mutations truncating the C‐terminus of the chemokine receptor CXC chemokine receptor 4 (CXCR4). WHIM mutations may potentiate CXCR4 signalling, suggesting that the United States Food and Drug Administration (FDA)‐approved CXCR4 antagonist AnorMED3100 (AMD3100) (also known as Plerixafor) may be beneficial in WHIM syndrome. We have tested this at the preclinical level by comparing Chinese hamster ovary (CHO) and K562 cell lines matched for expression of recombinant wild‐type CXCR4 (CXCR4WT) and the most common WHIM variant of CXCR4 (CXCR4R334X), as well as leucocytes from a WHIM patient with the CXCR4R334X mutation versus healthy controls. We found that CXCR4R334X mediated modestly increased signalling (∼2‐fold) in all functional assays tested, but strongly resisted ligand‐dependent down‐regulation. AMD3100 was equipotent and equieffective as an antagonist at CXCR4R334X and CXCR4WT. Together, our data provide further evidence that CXCR4R334X is a gain‐of‐function mutation, and support clinical evaluation of AMD3100 as mechanism‐based treatment in patients with WHIM syndrome.

Quantification of thyroid cancer and multinodular goiter risk in the DICER1 syndrome: a family-based cohort study.

Context: The risk of thyroid cancer and multinodular goiter (MNG) in DICER1 syndrome, a rare tumor-predisposition disorder, is unknown. Objective: To quantify the risk of thyroid cancer and MNG in individuals with DICER1 syndrome. Design: Family-based cohort study. Setting: National Institutes of Health (NIH) Clinical Center (CC). Participants: The National Cancer Institute DICER1 syndrome cohort included 145 individuals with a DICER1 germline mutation and 135 family controls from 48 families. Interventions: Each individual completed a detailed medical history questionnaire. A subset underwent a 3-day evaluation at the NIH CC. Main Outcome Measures: The cumulative incidence of MNG (or thyroidectomy) was quantified using the complement of the Kaplan-Meier product limit estimator. We compared the observed number of thyroid cancers in the NCI DICER1 cohort with matched data from the Surveillance, Epidemiology, and End Results (SEER) Program. We performed germline and somatic (thyroid cancer, MNG) DICER1 sequencing. Results: By the age of 40 years, the cumulative incidence of MNG or thyroidectomy was 75% in women and 17% in men with DICER1 syndrome compared with 8% of control women (P < 0.001) and 0% of control men (P = 0.0096). During 3937 person-years of observation, individuals with DICER1 syndrome had a 16-fold increased risk of thyroid cancer (95% confidence interval, 4.3 to 41; P < 0.05) compared with the SEER rates. Of 19 MNG nodules and 3 thyroid cancers, 16 (84%) and 3 (100%), respectively, harbored germline and somatic pathogenic DICER1 mutations. Conclusions: We propose a model of thyroid carcinogenesis in DICER1 syndrome. Early-onset, familial, or male MNG should prompt consideration of the presence of DICER1 syndrome.

CT of Pleural Abnormalities in Lymphangioleiomyomatosis and Comparison of Pleural Findings After Different Types of Pleurodesis

OBJECTIVE The objective of our article was to describe the spectrum and frequency of pleural abnormalities on CT in patients with lymphangioleiomyomatosis (LAM) and the pleural findings associated with different types of pleurodesis (talc, mechanical, and chemical) performed to treat the complications of pleural disease in these patients. MATERIALS AND METHODS Two hundred fifty-eight patients with LAM underwent CT of the chest. Pleural abnormalities assessed included pleural thickening, presence of a pleural mass, areas of high attenuation, effusion, and pneumothorax. In patients who had had pleurodesis, the CT findings were correlated with the type of procedure performed. RESULTS One hundred thirty-three (52%) of 258 patients had pleurodesis (unilateral, 68/133; bilateral, 65/133). Pleural abnormalities were more common in patients who had pleurodesis (101/133, 76%) than in those who had not (47/125, 38%) and were more prevalent on the operated side than on the unoperated side of those 68 patients who had unilateral pleurodesis. The frequencies of findings for the group without pleurodesis versus the group with pleurodesis were pleural thickening (26% vs 65%), effusion (10% vs 13%), loculated effusion (2.4% vs 11%), pneumothorax (1.6% vs 10%), areas of high attenuation (1.6% vs 23%), and mass (0.8% vs 14%), respectively. Areas of high attenuation in the pleura were present in all types of pleurodesis (mechanical, 8%; chemical, 13%; talc, 40%) and in two patients who had had repeated thoracentesis or pleurectomy. Pleural masses were present in patients who had had all types of pleurodesis (mechanical, 10%; chemical, 9%; talc, 24%) and in one patient who had had thoracentesis and thoracostomy; the masses commonly enhanced and did not change in size over time. CONCLUSION Pleural abnormalities are common in patients with LAM as complications of the disease itself and as sequelae of pleurodesis and other pleura manipulations. Pneumothorax and pleural effusion result from the underlying pathophysiology of LAM, whereas areas of high attenuation and masses develop after all types of pleurodesis and other manipulations of the pleura (i.e., thoracentesis, thoracostomy).

Macrocephaly associated with the DICER1 syndrome.

Purpose:Germ-line mutations in DICER1 increase the risk of various tumors, including pleuropulmonary blastoma. Macrocephaly and symmetric overgrowth have been reported in some, but not all, patients with mosaic DICER1 RNase IIIb mutations. The prevalence of these features in individuals with constitutional germ-line DICER1 mutations is unknown.Methods:We analyzed prospectively collected auxology data from 67 DICER1 mutation carriers and 43 family controls. We assessed differences between groups using an exact test for proportions and generalized estimating equations for continuous dependent variables.Results:Twenty-eight DICER1 mutation carriers (42%) were macrocephalic, and none had an occipitofrontal circumference (OFC) below the third centile, which significantly differed from family controls, of whom five were macrocephalic (12%) and two had OFC below the third centile (5%) (P < 0.001). DICER1 mutation carriers were taller than familial controls after controlling for gender (P = 0.048), but similar proportions of both groups were above the 97th centile of population norms. Head circumference remained increased after adjusting for differences in height.Conclusion:For the first time, we establish macrocephaly as a common finding in the DICER1 syndrome. Like some other tumor-predisposition disorders, macrocephaly may be a useful, albeit a subtle, clinical clue to the DICER1 syndrome diagnosis.Genet Med 19 2, 244–248.