Patients with chronic idiopathic neutropenia of adults have increased serum concentrations of inflammatory cytokines and chemokines

Incidence of Severe Chronic Neutropenia in South Korea and Related Clinical Manifestations: A National Health Insurance Database Study

Background and objectives: Severe chronic neutropenia (SCN) is a condition in which absolute neutrophil counts remain at a low level (under 500/µL) over months or years. Because of the rare onset of SCN, its epidemiology, prognosis, and clinical manifestations have not yet been fully understood. In particular, large-cohort studies in Asian countries are still insufficient. Therefore, in this study, national health insurance data was used to investigate the epidemiologic features and prognosis of SCN in South Korea. Materials and Methods: The data from the Health Insurance Review and Assessment database recorded between 1 January 2011 and 31 December 2015 were explored. SCN was defined based on the ICD-10 code, registry of benefit extension policy, and inclusion criteria of the study. After identifying patients with SCN, annual incidence and their co-morbidities were analyzed. Results: Among the initially identified patients with severe neutropenia (N = 2145), a total of 367 patients had SCN and were enrolled. The annual incidence rate of SCN ranged from 0.12 to 0.17 per 100,000 person-year (PY) during the study period. The highest incidence was observed in pediatric patients aged between 0 to 9 years (N = 156), followed by women in their fifties (N = 43). The total incidence rate was 0.17 in females and 0.12 in males (Relative risk (RR): 1.43, 95%, CI: 1.16–1.76). The most common accompanying condition was mild respiratory infection, but about 3.2% of patients progressed to hematologic malignancy after an average of 2.4 years. Conclusions: This nationwide population-based epidemiological study showed that incidence of SCN is higher in pediatrics and middle-aged women. As progression to hematologic malignancy was significantly higher in the age of in 45–49 years old, careful follow-up is necessary in this group. However, since this study lacks the molecular information, these finding need to be interpreted with great caution.

The Metabolic Cytokine Adiponectin Inhibits Inflammatory Lung Pathology in Invasive Aspergillosis

Systemic immunity and metabolism are coregulated by soluble factors, including the insulin-regulating adipose tissue cytokine adiponectin. How these factors impact detrimental inflammatory responses during fungal infection remains unknown. In this study, we observed that mortality, fungal burden, and tissue histopathology were increased in adiponectin-deficient mice in a neutropenic model of invasive aspergillosis. Lung RNA sequencing, quantitative RT-PCR, and subsequent pathway analysis demonstrated activation of inflammatory cytokine pathways with upstream regulation by IL-1 and TNF in adiponectin-deficient mice with decreased/inhibited anti-inflammatory genes/pathways, suggesting broad cytokine-mediated pathology along with ineffective fungal clearance. Quantitative RT-PCR analysis confirmed increased transcription of IL-1a, IL-6, IL-12b, IL-17A/F, and TNF in adiponectin-deficient mice at early time points postinfection, with a specific increase in intracellular TNF in alveolar macrophages. Although eosinophil recruitment and activation were increased in adiponectin-deficient mice, mortality was delayed, but not decreased, in mice deficient in both adiponectin and eosinophils. Interestingly, neutrophil depletion was required for increased inflammation in adiponectin-deficient mice in response to swollen/fixed conidia, suggesting that immune suppression enhances detrimental inflammation, whereas invasive fungal growth is dispensable. Our results suggest that adiponectin inhibits excessive lung inflammation in invasive aspergillosis. Our study has therefore identified the adiponectin pathway as a potential source for novel therapeutics in immune-compromised patients with detrimental immunity to invasive fungal infection.

Autoimmune hemolytic anemia, autoimmune neutropenia and aplastic anemia in the elderly

The physiology of the immune system involves morphologic and functional changes occurring along ageing, with a decrease in immune response and an increase in autoimmune phenomena, even in the absence of overt disese. Autoimmune cytopenias, namely autoimmune hemolytic anemia (AIHA), chronic idiopathic neutropenia (CIN) and aplastic anemia (AA), show different epidemiologic predilection, but are increasingly diagnosed in the elderly, where complications and comorbidities are more frequent. A systematic review of recent literature, shows that comorbidities as well as underlying deficiencies, medications, neoplasms, and, pathophysiologic chronic organ failures, frequently challenge the differential diagnosis in this setting and should always be evaluated and excluded. Complications, particularly infections and thrombosis for AIHA, and bleeding for AA, should be monitored and promptly treated. Treatment choice should be carefully weighed on the individual general condition and comorbidities, granted that intense primary care and support (including evidence-based transfusion policies) are provided. Finally, bone marrow histology is highly advisable in the elderly, both at diagnosis to detect underlying conditions, and along the follow-up to monitor possible bone marrow failure or neoplastic evolution.

Neutropenia and neutrophil-to-lymphocyte ratio in a healthy Korean population: race and sex should be considered

INTRODUCTION

We evaluated the prevalence and severity of asymptomatic neutropenia in a healthy Korean population according to sex and age. We explored normal neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in an asymptomatic Korean population and the association of these ratios with biomarkers related to inflammation, rheumatoid disease, and glucose metabolism.

METHODS

We analyzed complete blood cell counts in 83 740 subjects who participated in a routine health check-up program. NLR and PLR were compared to age, rheumatoid factor, C-reactive protein (CRP), erythrocyte sedimentation rate, hemoglobin A1c, and fasting glucose levels.

RESULTS

Of the entire study population, 7.48% exhibited neutropenia; 8.61% of females and 6.69% of males. The neutropenia was more severe in females compared to males (P < 0.01). Median NLR and PLR values were 1.53 and 121.07, respectively. An inverse relationship was observed between NLR and age, but no differences were seen between sexes. CRP, erythrocyte sedimentation rate, and fasting glucose level were significantly correlated with NLR.

CONCLUSION

Our data indicate that the normal range of absolute neutrophil counts should be adjusted and cutoff values for neutropenia should be re-established according to sex and race. NLR and PLR cutoff values for disease evaluation should be established separately according to race and age.

Is chronic neutropenia always a benign disease? Evidences from a 5-year prospective study

AIM

To evaluate infections and oncohematologic evolution in adult patients with chronic idiopathic and autoimmune neutropenia in a prospective study.

PATIENTS AND METHODS

76 consecutive patients were enrolled from September 2008 to April 2012. Complete blood counts and clinical evaluation were performed at enrolment, at month 3, 6, and then every 6 months. Anti-neutrophil antibodies were tested by GIFT method.

RESULTS

Patients (49 chronic idiopathic- and 27 autoimmune neutropenia) were followed for a median of 5 years (range 24-84 months). At enrolment, neutropenia was mild in 44 patients (median neutrophils 1.27×10(3)/μL), moderate in 23 (median 0.8×10(3)/μL), and severe in 9 (median 0.4×10(3)/μL). Neutrophil counts showed a great inter-subject but no intra-subject variability, with lower values in autoimmune neutropenia, in males, and in MGUS cases. Over time, no grade >3 infections occurred; 13/49 chronic idiopathic and 6/27 autoimmune neutropenia patients experienced a grade 2 event, irrespective of mean and nadir neutrophil values. Bone marrow evaluation at enrolment showed reduced cellularity in 23% of cases, and dyserythropoietic features in 55%, with no definite hematologic diagnosis. During the follow-up, 5 cases were diagnosed with NK expansion, 4 with hairy cell leukemia, and 3 with myelodysplasia (1 myelomonocytic leukemia, 1 refractory cytopenia with unilineage dysplasia, and 1 multilineage dysplasia), with a median time to evolution of 30 months.

CONCLUSION

Chronic idiopathic and autoimmune neutropenia, although usually benign, deserve hematological follow-up with a bone marrow evaluation at diagnosis and a re-evaluation in the presence of worsening neutropenia, appearance of additional cytopenias, and lymphocytosis.

How we evaluate and treat neutropenia in adults

Isolated neutropenia is a common clinical problem seen by primary care physicians and hematologists. The evaluation of neutropenia is dictated by the acuity of the clinical presentation and the duration, age, and clinical status of the patient. In this review, we provide a practical approach to the evaluation of the adult patient with neutropenia, with the major focus on the evaluation of neutropenia in the outpatient setting.

Genetic associations in acquired immune-mediated bone marrow failure syndromes: insights in aplastic anemia and chronic idiopathic neutropenia

Increasing interest on the field of autoimmune diseases has unveiled a plethora of genetic factors that predispose to these diseases. However, in immune-mediated bone marrow failure syndromes, such as acquired aplastic anemia and chronic idiopathic neutropenia, in which the pathophysiology results from a myelosuppressive bone marrow microenvironment mainly due to the presence of activated T lymphocytes, leading to the accelerated apoptotic death of the hematopoietic stem and progenitor cells, such genetic associations have been very limited. Various alleles and haplotypes of human leucocyte antigen (HLA) molecules have been implicated in the predisposition of developing the above diseases, as well as polymorphisms of inhibitory cytokines such as interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 along with polymorphisms on molecules of the immune system including the T-bet transcription factor and signal transducers and activators of transcription. In some cases, specific polymorphisms have been implicated in the outcome of treatment on those patients.

Increased levels of the high mobility group box 1 protein sustain the inflammatory bone marrow microenvironment in patients with chronic idiopathic neutropenia via activation of toll-like receptor 4

PURPOSE

Chronic idiopathic neutropenia (CIN) is a granulocytic disorder characterized by increased apoptosis of the bone marrow (BM) granulocytic progenitor cells and an inflammatory BM microenvironment. The aim of this study was to investigate the possible involvement of Toll-like receptors (TLRs) in the production of pro-inflammatory mediators in CIN BM.

METHODS

We evaluated the expression of TLRs in patient BM cell subsets and adherent cells of long-term BM cultures (LTBMCs) using flow cytometry. We also examined the activation of TLR-mediated signaling using real-time PCR arrays and explored for potential endogenous TLR-specific ligands in CIN BM.

RESULTS

CIN patients (n = 30) displayed significantly increased expression of surface TLR4 in monocytes of BM and LTBMC adherent cells compared to controls (n = 27). The TLR signaling gene array study in purified BM CD14(+) cells showed that numerous TLR-related genes displayed at least two-fold increase in patients compared to controls. Among the over-expressed genes were genes related to the MyD88-dependent and MyD88-independent pathway suggesting a TLR4-mediated signaling. BM plasma from CIN patients induced the production of pro-inflammatory mediators including interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and IL-8 by autologous BM monocytes, and this effect was abrogated by a specific TLR4 inhibitor. The levels of the high mobility group box 1 protein (HMGB1), representing a TLR4 ligand, were significantly increased in patient LTBMC supernatants compared to controls.

CONCLUSION

These data demonstrate a significant role of BM monocytes in the pathophysiology of CIN through the production of pro-inflammatory cytokines in a TLR4-mediated mechanism under the influence of endogenous ligands such as HMGB1.

Neutrophils sequestered in the liver suppress the proinflammatory response of Kupffer cells to systemic bacterial infection

The liver plays a major role in clearing bacteria from the bloodstream. Rapid clearance is primarily the function of fixed tissue macrophages (Kupffer cells) that line the hepatic sinusoids. Although Kupffer cells play a critical role in blood clearance, the actual elimination of the bulk of bacteria taken up by the liver depends upon the accumulation of bactericidal neutrophils. Subsequent experiments demonstrating neutrophils inside Kupffer cells derived from infected animals prompted our speculation that neutrophils modulate the proinflammatory response of Kupffer cells to bacteria cleared from the bloodstream. Indeed, we report here that neutrophils accumulated in the liver sinusoids suppress cytokine and chemokine mRNA expression and protein production by Kupffer cells. Using listeriosis in mice as an experimental model, we found that IL-1beta, IL-6, IL-10, IL-12, TNF-alpha, MIP-1alpha, keratinocyte-derived chemokine, and MCP-1 mRNA levels were >or=10-fold more in the livers of Listeria-infected, relative to noninfected control, mice at 0.5-2 h after i.v. infection. Most message levels were sharply diminished thereafter, correlating inversely with increased neutrophil sequestration. Relative to intact animals, mice rendered neutrophil deficient exhibited marked increases in cytokine/chemokine mRNA expression and protein production in the liver subsequent to infection. Moreover, purified Kupffer cells derived from infected, neutrophil-depleted mice produced significantly more IL-6, IL-10, IL-12, TNF-alpha, keratinocyte-derived chemokine, and MCP-1 in culture. These findings document the critical role of neutrophils in moderating the proinflammatory response of Kupffer cells to bacteria taken up by the liver.

Normal levels of constitutive and death receptor-mediated apoptosis of peripheral blood neutrophils from patients with chronic idiopathic neutropenia

To investigate the role of neutrophil apoptosis in the pathogenesis of chronic neutropenia, we examined constitutive and death receptor-mediated apoptosis ex vivo of peripheral blood neutrophils obtained from six chronic idiopathic neutropenia (CIN) patients and six healthy adult blood donors. Apoptosis was quantified based on phosphatidylserine externalization and caspase-3 activation in freshly isolated neutrophils or after overnight cultivation of neutrophils in the absence or presence of pro- or anti-apoptotic factors, including the pan-caspase inhibitor, zVAD-fmk. Neutrophils from CIN patients receiving treatment with granulocyte colony-stimulating factor appeared to be more prone to constitutive apoptosis than cells from untreated patients; however, further investigations in larger cohorts of patients are needed to validate these pilot studies. Overall, the level of neutrophil apoptosis was similar in patient and control groups, thus supporting the notion that the underlying defect in these neutropenia patients lies elsewhere, such as in the bone marrow microenvironment.

Ethnic differences in plasma levels of interleukin-8 (IL-8) and granulocyte colony stimulating factor (G-CSF)

Ethnic neutropenia is common in people of African descent. As interleukin-8 (IL-8) and granulocyte colony stimulating factor (G-CSF) bind to receptors on neutrophils, ethnic differences in neutrophil counts are hypothesized to result in different plasma levels of these cytokines. A prospective study was conducted in 72 healthy young volunteers. Neutrophil counts were 60% higher in Caucasians (P<0.00001). Average IL-8 and G-CSF levels were about 50% and 70% higher in African volunteers compared with Caucasian volunteers (P=0.0008 and P=0.00005, respectively). Additionally, oxidative burst capacity in stimulated neutrophils was significantly lower in volunteers of African descent (P=0.03 between both groups). In sum, lower neutrophil counts are associated with higher levels of IL-8 and G-CSF in Africans.

Causes of incidental neutropenia in adulthood

The incidental discovery of neutropenia during routine blood counting represents a common problem for clinicians. However, there are no reported data of systematic evaluations of adults with incidental neutropenia. As such, this was the aim of the present study. Ninety-seven adults with incidental neutropenia were submitted to a clinical and laboratory approach including medical evaluation, complete blood count (CBC), serial CBC, direct and indirect antiglobulin test, bone marrow smear and biopsy, assessment of folate, vitamin B12 and iron status, serum liver enzymes, serum proteins, serological exams for hepatitis B and C virus, cytomegalovirus, mononucleosis, human immunodeficiency virus and toxoplasmosis, detection of lupus erythematosus cells, antinuclear and anti-DNA antibodies and rheumatoid factor, dosage of free thyroxin and thyrotropin, chest roentgenogram and abdominal echography. Chronic idiopathic neutropenia of adults was identified in 34.0% of the individuals, neutropenia due to exposure to chemical agents was seen in 16.5%, infectious diseases in 9.3%, autoimmune diseases in 9.3%, haematological diseases in 9.3%, thyroid disorders in 8.2%, ethnic neutropenia in 7.2%, drug-related neutropenia in 2.1%, cyclic neutropenia in 2.1% and iron deficiency in 2.1%. Recovery or improvement of the neutrophil count was seen upon treatment or recuperation from infectious, autoimmune, haematological and thyroid diseases and iron supplementation. We conclude that the evaluation of individuals with incidental neutropenia using a structured approach may make the identification of clinically silent diseases possible, and provide an opportunity for early treatment, avoiding complications of the diseases and consequences of neutropenia.

Increased levels of soluble flt-3 ligand in serum and long-term bone marrow culture supernatants in patients with chronic idiopathic neutropenia

The levels of serum and long-term bone marrow culture supernatant soluble flt-3 ligand (sFL) were determined in 54 patients with chronic idiopathic neutropenia (CIN) and 16 normal controls. Both serum and supernatant sFL levels were significantly increased in the patients compared with controls. Individual sFL values inversely correlated with the number of circulating neutrophils and the proportion of bone marrow CD34+ cells. Supernatant sFL values positively correlated with the levels of supernatant G-CSF. These findings suggest that the impaired myelopoiesis in CIN patients is accompanied by a compensatory mechanism attempting to increase the neutrophil production at the myeloid progenitor cell level.

Helicobacter pylori infection is probably the cause of chronic idiopathic neutropenia (CIN)-associated splenomegaly

Splenic volume and Helicobacter pylori (H. pylori) infection were evaluated in 67 patients with chronic idiopathic neutropenia (CIN) and 39 healthy individuals. Using ultrasound, splenomegaly was found in 61.7% of H. pylori-infected subjects compared to only 8.7% noted in the group of H. pylori-non-infected individuals (P < 0.0001). Splenomegaly was also found in 47.8% of CIN patients compared to 12.8% in the group of non-CIN subjects (P = 0.0003). However, applying the two-way ANOVA test, a statistically significant effect on splenic volume was documented for "factor H. pylori " (F1(102) = 16.800, P < 0.0001) but not for "factor CIN" (F1(102) = 3.213, P = 0.0760), suggesting that CIN-associated splenomegaly is probably due to H. pylori infection.

Soluble c-kit ligand production by bone marrow stromal cells is independent of the degree of neutropenia in patients with chronic idiopathic neutropenia

The levels of soluble c-kit ligand (sKL), also known as Steel factor or stem cell factor, were measured in blood serum and long-term bone marrow culture supernatants of 81 patients with chronic idiopathic neutropenia (CIN) and 22 normal controls using a commercially available enzyme-linked immunosorbent assay (ELISA). We found that the levels of serum and culture supernatant sKL did not differ significantly between patients and control subjects and that both serum and supernatant values of the cytokine did not correlate with the number of circulating neutrophils. Furthermore, we found that the levels of the culture supernatant granulocyte colony-stimulating factor (G-CSF), also measured by ELISA, were significantly increased in the patients compared to controls but individual G-CSF values did not correlate with the values of supernatant sKL. These findings suggest that sKL-producing cells continuously secrete sKL and that cytokine secretion is independent of the degree of neutropenia or the levels of supernatant G-CSF in patients with CIN.

Neutropenia: Etiology and Pathogenesis

Neutropenia is defined as an absolute neutrophil count <1500 cells/mm(3) and can be graded as mild (1000-1500 cells/mm(3)), moderate (500-1000 cells/mm(3)), or severe (<500 cells/mm(3)). Neutropenia can develop as a result of > or =1 pathologic mechanism, including decreased bone marrow production, the sequestering of neutrophils, and increased destruction of neutrophils in the peripheral blood. The clinical result is increased risk for infection. This risk is directly proportional to the severity and duration of neutropenia. Neutropenia is classified according to the etiology as congenital or acquired, with the latter further defined according to the etiology or pathology. Febrile neutropenia is associated with substantial morbidity and even mortality.

Polymorphisms of interleukin-1 gene complex, IL6 and tumour necrosis factor genes in chronic idiopathic neutropenia of adults

Chronic idiopathic neutropenia of adults (CINA) is a granulocytic disorder characterised by the "unexplained" decrease in the number of circulating neutrophils. Serum inflammatory cytokines and chemokines are increased in CINA. In addition, cytokines gene polymorphisms are associated with increased levels of respective products and related with inflammatory diseases. The aim of the present study was to investigate the association of polymorphisms of IL1B-511C/T and +3953C/T, IL1RN intron 2, IL6-174G/C and TNF-308G/A genes with CINA. We analysed 29 CINA and controls by polymerase chain reaction and restriction fragment length polymorphism. Statistical analyses were performed using chi2 test, and the Hardy-Weinberg equilibrium (HWE) was investigated. All alleles analysed were in HWE in both populations. Similar frequencies of IL1B-511C/T, IL1B+3953C/T, IL1RN, IL6-174G/C and TNF-308G/A genotypes were observed in CINA and controls. These results suggest that cytokine polymorphisms associated with control of gene expression and protein levels were not associated with occurrence of CINA and were not responsible for the increased cytokine in CINA patients.

Transcriptional regulation of TNF-α production in neutropenia

Neutropenia has been shown to markedly increase plasma TNF-α concentration after LPS injection and to enhance LPS-induced mortality. Experiments reported here demonstrate that the 15-fold higher plasma TNF-α concentration elicited by LPS in neutropenic vs. nonneutropenic unanesthetized mice correlated with increased hepatic and splenic, but not pulmonary, TNF-α mRNA. Core 2 β-1,6- N-acetylglucosaminyltransferase-null and CD18-deficient mice also exhibited exaggerated plasma TNF-α responses to LPS injection. Findings suggest that extravasated neutrophils inhibit systemic TNF-α production and that they do so through organ-selective mechanisms involving CD18 integrin and selectin binding.

Perspectives on cancer immuno-epidemiology

Estimating human cancer risk based on host-environment interaction is one task of epidemiology, and it has provided indispensable knowledge for prevention of cancer. The recent develop-ment of gene-engineered mice has also provided solid evidence about the relationship between cancer development and immunity. The aim of this review is to discuss the possible contribution of epidemiology to understanding the role of immunity in host defense against cancer, and also to assess the involvement of inflammation in the occurrence of selected cancers. Here we look at the concepts of cancer immunosurveillance and infection-inflammation-cancer, and include a brief introduction to recent studies in humans and experimental animal models. It has been postulated for many years that the immune system has the ability to recognize and eliminate nascent transformed cells in the body (so-called cancer immunosurveillance hypothesis), and this idea has recently obtained strong support from animal experiments. In humans, follow-up studies among immunosuppressed transplant recipients revealed a remarkably increased risk of not only selected malignancies, but also cancers with no known viral etiology. On the other hand, a prospective cohort study among the general population revealed that individuals with low natural cytotoxic activity of peripheral blood lymphocytes had an increased risk of cancer development. More studies are warranted to allow the construction of a model for the interaction between host immunity, aging, and the environment. The host immune system is also involved in inflammatory responses to pathogen infection: insufficient immune function of the host, or repeated infection, may result in persistent inflammation, where growth/survival factors continuously act on initiated cells. The combined use of biomarkers will be necessary to define low-grade persistent inflammation in future cohort studies; and, in addition to these phenotype marker-based cohort studies, one plausible future direction will be a genomic approach that can be undertaken within cohort studies, looking at the genetic background underlying individual variations in phenotype markers.

Recovery of Neutrophil Count by Ganciclovir in Patients with Chronic Idiopathic Neutropenia Associated with Cytomegalovirus Infection in Bone Marrow Stromal Cells

Patients with chronic idiopathic neutropenia (CIN) usually show chronic inflammation in their bone marrow stromal cells, but the etiologies of this disorder are still unknown. We suspected viral infection of the bone marrow stromal cells and used polymerase chain reaction (PCR) analysis to test for cytomegalovirus (CMV) infection in 4 patients with CIN and in 6 healthy volunteers. Peripheral blood mononuclear cells did not yield signals in any of the patients or healthy volunteers, but PCR analysis for CMV DNA in bone marrow stromal cells showed positive signals in 2 of the patients with CIN. CMV DNA was not detected in the other 2 patients or in the healthy volunteers. The 2 patients who were positive for stromal CMV received 500 mg/day ganciclovir for 14 days. After this treatment, the PCR band showing the presence of stromal CMV disappeared, and the neutrophil numbers of the 2 patients who received this viral eradication therapy normalized 6 months after treatment. In conclusion, the etiology in some cases of CIN is speculated to be infection by CMV in bone marrow stromal cells, and treatment with ganciclovir may be effective in treating such patients.

Congenital and Acquired Neutropenia

Our understanding of the pathogenesis of congenital and acquired neutropenia is rapidly evolving. New ground-breaking observations have identified the genes responsible for many of the congenital neutropenia syndromes and are also providing new insights into normal neutrophil commitment and differentiation. Acquired neutropenia remains a poorly understood syndrome, although new insights into its pathogenesis are also emerging, especially with regard to subsets of immune neutropenia.

In Section I, Dr. Marshall Horwitz reviews the current understanding of the genetic basis, molecular pathology, and approaches to treatment of congenital neutropenia and cyclic hematopoiesis. Mutations in the ELA2 gene, which encodes for neutrophil elastase, cause cyclic hematopoiesis. ELA2 mutations are also the most common cause of congenital neutropenia, where their presence may equate with a more severe clinical course and higher frequency of leukemic progression. Emerging evidence indicates interrelatedness with Hermansky Pudlak syndrome and other disorders of neutrophil and platelet granules.

In Section II, Dr. Nancy Berliner presents an overview of the clinical approach to the evaluation and treatment of acquired neutropenia. This includes a review of the pathogenesis of primary and secondary immune neutropenia, drug-induced neutropenia, and non-immune chronic idiopathic neutropenia of adults. Studies used to evaluate patients for potential immune neutropenia are reviewed. Management issues, especially the use of granulocyte colony-stimulating factor (G-CSF), are discussed.

In Section III, Dr. Thomas Loughran, Jr., reviews the pathogenesis and clinical manifestations of large granular lymphocyte (LGL) leukemia. Possible mechanisms of neutropenia are discussed. In particular, discussion focuses on the relationship between LGL leukemia, rheumatoid disease, and Felty’s syndrome, and the complex interplay of defects in neutrophil production, distribution, destruction, and apoptosis that underly the development of neutropenia in those syndromes.

Cyclosporine A effectively inhibits graft-versus-host disease during development of Epstein-Barr virus-infected human B cell lymphoma in SCID mouse

We previously constructed human peripheral blood lymphocyte (hu-PBL)/severe combined immunodeficiency mouse (SCID) chimeras and induced human B-cell lymphomas associated with Epstein-Barr virus (EBV) in SCID mice. However, a number of SCID mice died of graft-versus-host disease (GVHD) during the early experimental course. The aim of this study was to test the efficacy of cyclosporine A (CSA) for prevention of GVHD and to define how CSA inhibits the occurrence of GVHD and the production of soluble interleukin (IL) 2 receptor (sIL-2R) in hu-PBL/SCID mice. No mouse died in the active EBV infection group with CSA administration, while 17 mice in three groups without CSA administration died of GVHD. Mortalities in these three groups were 55.56% (5/9), 30.43% (7/23), and 27.78% (5/18), and the medium life span was 17 days. Over the first 33 days after hu-PBL transplantation, serum level of human sIL-2R in hu-PBL/SCID chimeras was stable in the active EBV infection plus CSA group, while sIL-2R concentration gradually increased in the sera of mice with active EBV infection without CSA administration and peaked at 22 days. Thirty-two mice developed tumors among the 43 surviving SCID mice. There was no significant difference of tumor incidence between the active EBV infection groups with CSA and without CSA administration (P > 0.05). From their morphological and immunohistochemical features, as well as detection of human Alu-sequence and EBV in tumor cells, these EBV-induced tumors were identified as human B-cell lymphomas. Thus, CSA can strikingly inhibit GVHD in hu-PBL/SCID chimeras, and should therefore be effective to establish a stable SCID mouse model of human lymphoma associated with EBV. Treatment with CSA had no effect on the tumor incidence in hu-PBL/SCID chimeras after active EBV infection. Accordingly, serum level of sIL-2R is a valuable indicator of GVHD occurrence in hu-PBL/SCID chimeras.

Effect of intense exercise on inflammatory cytokines and growth mediators in adolescent boys

OBJECTIVE

Exercise can enhance growth and development in children, but recent investigations have revealed an intriguing paradox. Namely, the early (4-5 weeks) response to training programs in children lead to a catabolic, growth hormone (GH)-resistant state rather than the expected anabolic activation of the GH-->insulin-like growth factor-I (IGF-I) axis. This paradox led us to hypothesize that single bouts of exercise in children could stimulate proinflammatory cytokines known to inhibit directly anabolic activity of the GH-->IGF-1 axis (interleukin [IL]-6, IL-1beta, and tumor necrosis factor-alpha [TNF-alpha]).

METHODS

Eleven healthy high school-age boys, age 14 to 18.5 years, performed a single, typical, 1.5-hour wrestling practice session. Blood was sampled before and after the session.

RESULTS

We found significant decreases in anabolic mediators: total IGF-I (-11.2 +/- 2.3%), bound IGF-I (-11.2 +/- 2.4%), and insulin (-42 +/- 10%. However, there was no change in unbound IGF-I. Remarkable increases were found in proinflammatory cytokines IL-6 (795 +/- 156%), TNF-alpha (30 +/- 12%), and IL-1beta (286 +/- 129%) and in IGF-binding protein-1 (835 +/- 234%), which itself is stimulated by inflammatory cytokines and is known to inhibit IGF-I. Evidence for compensatory mechanisms to counter the antianabolic inflammatory response to acute exercise were also noted: IL-1ra increased (80 +/- 20%) and IGF-binding protein-3 proteolysis (which can maintain unbound, biologically active IGF-I despite losses in total IGF-I) increased significantly (101 +/- 39%) as well.

CONCLUSIONS

These data demonstrate that an intense exercise bout in male adolescents leads to reductions in anabolic mediators and profound increases in inflammatory cytokines. This might explain the development of what seems to be a paradoxical catabolic state in the initial phases of exercise training programs.

Non-immune chronic idiopathic neutropenia of adult: an overview

There is strong evidence that non-immune chronic idiopathic neutropenia of adult is a cytokine-mediated syndrome characterized by (a) neutropenia of varying degree associated with a low number of lineage-specific CD34+ cells and increased production of inhibitors of hematopoiesis, including transforming growth factor-beta1 and tumor necrosis factor-alpha; (b) lymphopenia due to selective loss of primed/memory T-cells and NK cells; (c) increased splenic volume on ultrasonography in 48.1% of patients; (d) osteopenia and/or osteoporosis in 60.0% of patients; (e) anemia, mostly of the type of anemia of chronic disease, in 15.6% of patients; (f) features of chronic antigenic stimulation, including increased proportion of bone marrow plasma cells, increased serum levels of IgG1 and/or IgA, increased frequency of monoclonal gammopathy of undetermined significance, increased frequency of antinuclear antibodies with specific reactivity, and increased serum levels of circulating immune complexes; and (g) increased concentrations of a variety of macrophage-derived pro-inflammatory cytokines and chemokines capable of affecting bone metabolism, bone marrow function, and leukocyte trafficking. All these findings are suggestive of the existence of an unrecognized low-grade chronic inflammatory process which may be involved in the pathogenesis of the disorder. Neutropenia in these patients is probably the result of a combination of at least three factors, reduced neutrophil production in bone marrow, enhanced neutrophil extravasation, and increased sequestration and/or extravasation of neutrophils into the spleen.

Increased frequency and specific reactivity of serum antinuclear antibodies in patients with nonimmune chronic idiopathic neutropenia of adults

This study describes the frequency of serum organ-specific and organ-nonspecific autoantibodies in 157 patients with nonimmune chronic idiopathic neutropenia of adults (NI-CINA). Forty-two age- and gender-matched volunteers were used as controls. We found that patients with NI-CINA had increased frequency of antinuclear antibodies (ANA) compared to controls (33.1 vs. 9.5%, p = 0.0025), and that ANA positivity inversely correlated with the number of circulating neutrophils (r = -0.2765, p < 0.0001). Speckled pattern of reactivity was seen in 84.6% of ANA-positive patients, and diffuse pattern in the remaining 15.4%. Patients had also increased levels of circulating immune complexes compared to controls (3.30 +/- 2.41 vs. 1.70 +/- 1.19 microg/ml, p = 0.0042), which inversely correlated with the number of circulating neutrophils (r = -0.2405, p = 0.0154) but not with the titer of ANA positivity. No significant differences were found between the patients and the normal controls in the frequency of positive tests for antibodies to dsDNA, Sm, nRNP, SSA, SSB and Scl-70 antigens, or for parietal cell antibodies, anti-neutrophil cytoplasmic antibodies (ANCA), anti-cardiolipin and anti-thyroid antibodies. Serum levels of rheumatoid factor, C-reactive protein (CRP) and complement factors C3 and C4 ranged within normal limits in the patients studied, but a highly significant correlation was noted between the levels of CRP and ANA positivity (r = 0.3936, p < 0.0001). These findings are suggestive of a chronic inflammation in NI-CINA patients which provides the antigenic stimulus for ANA production, and they further support our previously reported suggestion for the possible involvement of such a low-grade chronic inflammatory process in the pathogenesis of neutropenia in the affected subjects.

Interleukin-8 receptor antagonists in pulmonary diseases

Inflammatory cells are thought to be instrumental in the pathophysiology of pulmonary diseases, and control of their recruitment and activation in the lung would appear to be an attractive strategy for therapeutic intervention. Interleukin-8 and related CXC chemokines are involved in the function of neutrophils and T cells, and have been implicated in several lung diseases. Small-molecule antagonists of the interleukin-8 receptors have been identified, which may help elucidate the role of interleukin-8 and related chemokines in the pathophysiology of lung diseases.

Patients with non-immune chronic idiopathic neutropenia syndrome have increased splenic volume on ultrasonography

Clinically detectable splenomegaly is rarely seen in patients with non-immune chronic idiopathic neutropenia syndrome (NI-CINS). Using ultrasound, we estimated splenic volume in 52 NI-CINS patients and 14 age- and sex-matched normal controls by determining the "corrected splenic index" (CSI) from the product of length, width and thickness of the organ expressed in cm3/m2 body surface area. We found that CSI was significantly higher in the group of patients compared to controls (202.8 +/- 82.0 vs. 133.8 +/- 28.1 cm3/m2, P=0.003), and that individual CSI values was inversely correlated with the number of circulating neutrophils (r=-0.5097, P < 0.0001). About 48.1% of the patients had CSI above 190 cm3/m2 body surface, representing the upper 95% confidence limit of values found in the controls. Patients also had increased serum concentrations of pro-inflammatory cytokines and chemokines mainly produced by activated macrophages (IL-1beta, TNF-alpha, RANTES and IL-8), as well as increased serum levels of soluble cell adhesion molecules derived from activated endothelium (sE-Selectin, sICAM and sVCAM). We hypothesize that the increased splenic volume in NI-CINS patients may be due to the accumulation of activated macrophages inside the spleen, possibly as the result of an unrecognized low-grade chronic inflammatory process. The nature of such an inflammation is unknown. A study was designed to search for viral or bacterial genomic material in patients' bone marrow stromal macrophages in which the unknown causal agent might be located.

Increased frequency of monoclonal gammopathy of undetermined significance in patients with nonimmune chronic idiopathic neutropenia syndrome

This study describes the frequency of monoclonal gammopathy of undetermined significance (MGUS) and the changes in some inflammation-related serum proteins in 157 patients with nonimmune chronic idiopathic neutropenia syndrome (NI-CINS). Of these patients, 42 had pronounced neutropenia with neutrophil counts < 1500/microL, and 115 had mild neutropenia with neutrophil counts ranging from 1500 to 2499/microL. Sixty-six volunteers served as healthy control subjects and 157 age- and sex-matched patients hospitalized for nonmalignant diseases served as patient control subjects. We found that 28.6% of patients with pronounced neutropenia and 14.8% of patients with mild neutropenia had increased serum gamma globulins (above the 95% confidence limit of values of the control subjects). In the group of patients with pronounced neutropenia, 30.9% had increased immunoglobulin (Ig)G values and 23.8% had increased IgA values. In the group of patients with mild neutropenia, 17.4% had increased IgG values and 21.7% had increased IgA values. IgG and IgA values strongly correlated with the neutrophil count. No changes in serum IgM were found. Three of 42 patients with pronounced neutropenia (7.14%) and 3 of 115 patients with mild neutropenia (2.61%) had serum immunofixation tests which showed a small monoclonal spike--4 were IgG-kappa type, 1 was IgG-lambda type, and 1 was IgA-kappa type. None of the healthy or patient control subjects had any evidence of MGUS. No significant changes in the amount of monoclonal spikes were documented during an 18- to 143-month follow-up (median, 58 months). Except for significantly increased alpha1-antitrypsin levels, there were no significant differences in the levels of acute-phase proteins studied between the study patients and the control subjects. These findings are consistent with our previous report suggesting the possible existence of an unrecognized low-grade chronic inflammation in patients with NI-CINS, which may be involved in the pathogenesis of neutropenia in the affected subjects.