Tumor necrosis factor alpha promoter polymorphism associated with increased susceptibility to secondary hemophagocytic lymphohistiocytosis in the Korean population

Secondary hemophagocytic lymphohistiocytosis in children (Review)

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by hyperinflammation in an uncontrolled and ineffective immune response. Despite great improvement in diagnosis and treatment, it still represents a challenge in clinical management, with poor prognosis in the absence of an aggressive therapeutic approach. The present literature review focuses on secondary HLH at pediatric age, which represents a heterogeneous group in terms of etiology and therapeutic approach. It summarizes the most recent evidence on epidemiology, pathophysiology, diagnosis, treatment and prognosis, and provides a detailed description and comparison of the major subtypes of secondary HLH. Finally, it addresses the open questions with a focus on diagnosis and new treatment insights.

Polymorphisms and haplotypes of IL2RA, IL10, IFNG, IRF5, and CCR2 are associated with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

OBJECTIVE

Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies have shown that single-nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. As such, we investigated the association between susceptibility to EBV-HLH in children and SNPs and haplotypes of genes encoding interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL10), interferon gamma (IFNG), interferon regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2).

METHODS

Sixty-six children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in this study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656; IL10 rs1800896, rs1800871, and rs1800872; IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique.

RESULTS

Frequencies of the A allele of IL2RA rs2104286 and IL10 rs1800896, and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group than in the control group. The AA genotype of IL2RA rs2104286 and IL10 rs1800896, and the CC genotype of IL10 rs1800872 might be associated with a significantly high risk of EBV-HLH. However, the frequencies of genotypes and alleles of IL2RA rs2104286, IL10 rs1800871, IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. Additionally, IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also associated with an increased risk of EBV-HLH.

CONCLUSIONS

SNPs of IL2RA rs2104286, IL10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL10 ACC were highly associated with susceptibility to EBV-HLH in children.

Relationship between cytokine gene polymorphisms and risk of postoperative pneumonia with esophageal cancer

BACKGROUND

We retrospectively evaluated the relationship between cytokine gene polymorphisms and development of postoperative pneumonia after esophagectomy.

METHODS

In 120 patients who underwent esophagectomy, serum samples were obtained to measure levels of serum interleukin (IL)-6 and IL-10 at four time points (preoperatively, postoperative day (POD)0, POD1, and POD3). DNA extracted from peripheral blood in all patients was analyzed to determine polymorphisms of cytokines such as tumor necrosis factor-α -1031 T/C, IL-1β -511C/T, IL-6 -634C/G, and IL-10 -819 T/C.

RESULTS

Postoperative pneumonia arose in 34 patients (28.3 %). Perioperative serum IL-10 levels were significantly higher for IL-10 -819 C/T + C/C genotypes than for T/T genotypes (POD0 16.7 ± 2.84 vs. 8.54 ± 0.87 pg/ml, p = 0.0002; POD1 14.0 ± 2.64 vs. 8.8 ± 0.87 pg/ml, p = 0.0143; POD3 8.9 ± 2.67 vs. 4.4 ± 0.52 pg/ml, p = 0.0076). The frequency of the IL-10 -819 T/T genotype was significantly higher in patients with postoperative pneumonia than in patients without pneumonia (p = 0.0323). Multivariate analysis of factors such as sex, smoking, length of operation, field of lymph node dissection, and IL-10 polymorphism identified IL-10 polymorphism as independent predictor of postoperative pneumonia.

CONCLUSIONS

Patients with IL-10 -819 T/T genotype may be at high risk for postoperative pneumonia after esophagectomy.

Hemophagocytic syndrome in an acute human immunodeficiency virus infection

Hemophagocytic syndrome (HPS) is an unrecognized complication occurring in the acute stage of human immunodeficiency virus (HIV) infection that is seldom reported in the literature. We herein present a case of HPS that occurred during the seroconversion stage of HIV infection. In this case, pancytopenia and liver dysfunction related to HPS recovered after the initiation of antiretroviral therapy (ART). This report indicates the importance of early recognition of HPS and suggests that prompt initiation of ART has the potential to control HPS in the acute stage of HIV infection.

Screening the PRF1, UNC13D, STX11, SH2D1A, XIAP, and ITK gene mutations in Chinese children with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

BACKGROUND

This study aimed to investigate the prevalence of mutations in the PRF1, UNC13D, STX11, SH2D1A, XIAP, and ITK in Chinese pediatric patients with EBV-HLH.

METHODS

Sixty-seven pediatric patients diagnosed with EBV-HLH in Beijing Children's Hospital were recruited. Nucleotide sequences of all exons and their flanking intronic sequences of PRF1, UNC13D, STX11, SH2D1A, XIAP, and ITK were amplified by PCR followed by direct sequencing.

RESULTS

Eight patients were identified with heterozygous, compound heterozygous, or homozygous mutations in PFR1, UNC13D, and XIAP. Three missense mutations (c.83G>A, c.503G>A, c.632C>T) were found in PRF1 of two males and two females. Compound heterozygous c.93C>G and c.1066C>T were found in PRF1 of a 2.5-year-old female. Four different mutations were found in UNC13D of two patients: compound nonsense heterozygous mutations c.766C>T and c.1215C>G were found in one male and two splicing mutations c.1596+1G>C and c.2709+1G>A were found in another male. A heterozygous mutation c.1099+2T>C in XIAP was found in a 4-year-old male. No detrimental mutations were identified in STX11, SH2D1A, or ITK. NK cell activity did not differ between the eight FHL patients and the remaining patients. There was no statistical difference in clinical features and laboratory data for these two subgroups with biallelic and heterozygous mutations.

CONCLUSIONS

Seven novel mutations in PRF1, UNC13D, and XIAP were identified in EBV-HLH patients. Only a fraction of the Chinese children with EBV-HLH have genetic defects in PRF1, UNC13D, and XIAP. There were no gene mutations of PRF1/UNC13D/STX11/SH2D1A/XIAP/ITK in the majority of Chinese child patients with EBV-HLH.

Association of polymorphisms in the promoter regions of TNF-α (-308) with susceptibility to hepatitis E virus and TNF-α (-1031) and IFN-γ (+874) genes with clinical outcome of hepatitis E infection in India

BACKGROUND & AIMS

Hepatitis E virus (HEV) is the predominant cause of acute viral hepatitis (AVH-E) and acute liver failure (ALF-E) among adults from developing countries. Pathogenesis of hepatitis E is poorly understood. Earlier, we showed association of elevated serum levels of TNF-α, IFN-γ, and IL-12 with ALF-E. The role of TNF-α and IFN-γ gene promoter polymorphisms with disease severity was investigated.

METHODS

The study population included 374 anti-HEV negative apparently healthy controls, 136 subclinical hepatitis E, 353 AVH-E, and 25 ALF-E patients. Polymorphisms at promoter regions of TNF-α-308G/A, TNF-α-1031T/C, and IFN-γ+874T/A were investigated employing allelic discrimination/SNaPshot™ methods.

RESULTS

ALF-E patients were younger with significantly higher ALT levels when compared to other categories. Genotype TNF-α-308AA frequency was significantly higher among subclinical and clinical hepatitis E than the controls (p=0.03, 0.0007). No significant difference was observed among AVH-E/ALF-E groups. The -308A allele was significantly higher in HEV-infected individuals; fatal ALF patients showed higher frequency than the recovered (p=0.024). TNF-α-1031CC, IFN-γ+874TT, and IFN-γ+874TA genotypes were significantly associated with clinical disease. With respect to the controls, genotype+874TA was more frequent in subclinical infection (p=0.005) while+874AA frequency was lower in the AVH-E category (p=0.003).

CONCLUSIONS

The data reveal association of TNF-α-308AA genotype with susceptibility to HEV and that of TNF-α-1031CC and IFN-γ+874TT and TA with clinical disease, irrespective of the outcome. Higher -308A allele frequency was associated with susceptibility to HEV and the fatal outcome of ALF-E.

Viral infections associated with haemophagocytic syndrome

Haemophagocytic syndrome (HPS) or haemophagocytic lymphohistiocytosis (HLH) is a rare disease caused by a dysfunction of cytotoxic T cells and NK cells. This T cell/NK cell dysregulation causes an aberrant cytokine release, resulting in proliferation/activation of histiocytes with subsequent haemophagocytosis. Histiocytic infiltration of the reticuloendothelial system results in hepatomegaly, splenomegaly, lymphadenopathy and pancytopenia ultimately leading to multiple organ dysfunctions. Common clinical features include high fevers despite broad spectrum antimicrobials, maculopapular rash, neurological symptoms, coagulopathy and abnormal liver function tests. Haemophagocytic syndrome can be either primary, i.e. due to an underlying genetic defect or secondary, associated with malignancies, autoimmune diseases (also called macrophage activation syndrome) or infections. Infectious triggers are most commonly due to viral infections mainly of the herpes group, with EBV being the most common cause. HPS can be fatal if untreated. Early recognition of the clinical presentation and laboratory abnormalities associated with HPS and prompt initiation of treatment can be life saving. HPS triggered by viral infections generally does not respond to specific antiviral therapy but may be treated with immunosuppressive/immunomodulatory agents and, in refractory cases, with bone marrow transplantation. Copyright © 2010 John Wiley & Sons, Ltd.

Secondary hemophagocytic lymphohistiocytosis and severe sepsis/ systemic inflammatory response syndrome/multiorgan dysfunction syndrome/macrophage activation syndrome share common intermediate phenotypes on a spectrum of inflammation

In an effort to attain earlier diagnoses in children with hemophagocytic lymphohistiocytosis (HLH), the International Histiocyte Society has now broadened their diagnostic criteria to no longer differentiate primary (HLH) and secondary hemophagocytic lymphohistiocytosis (SHLH). Five of the following eight diagnostic criteria needed to be met: 1) fever, 2) cytopenia of two lines, 3) hypertriglyceridemia and/or hypofibrinogenemia, 4) hyperferritinemia (>500 microg/L), 5) hemophagocytosis, 6) elevated soluble interleukin-2 receptor (CD25), 7) decreased natural killer-cell activity, and 8) splenomegaly can also commonly be found in patients with sepsis, systemic inflammatory response syndrome (SIRS), multiorgan dysfunction syndrome (MODS), and macrophage activation syndrome (MAS). Nevertheless, the therapeutic options for these are radically different. Chemotherapy and bone marrow transplant have been used for treatment of HLH/SHLH, whereas antibiotics and supportive treatment are used in severe sepsis/SIRS and MODS. MAS is treated with limited immune suppression. Outcomes are also different, SHLH has a mortality rate around 50%, whereas pediatric septic shock and MODS have a mortality of 10.3% and 18%, respectively, and severe sepsis in previously healthy children has a mortality rate of 2%. MAS has a mortality rate between 8% and 22%. Because SHLH and severe sepsis/SIRS/MODS/MAS share clinical and laboratory inflammatory phenotypes, we recommend extreme caution when considering applying HLH therapies to children with sepsis/SIRS/MODS/MAS. HLH therapies are clearly warranted for children with HLH; however, a quantitative functional estimate of cytotoxic lymphocyte function may be a more precise approach to define the overlap of these conditions, better identify these processes, and develop novel therapeutic protocols that may lead to improved treatments and outcomes.