Prognostic role of Interleukin-6/lymphocytes ratio in SARS-CoV2 related pneumonia.

INTRODUCTION AND AIM: Interleukin-6 to lymphocyte (IL-6/Lym) ratio has been identified as a potential prognostic tool in patients with SARS-CoV2 related pneumonia. The aim of our study was to compare the prognostic power of IL-6/Lym ratio with other biomarkers in patients initially admitted in a non intensive unit and suffering for respiratory failure associated with SARS-CoV2 related pneumonia. MATERIALS AND METHODS: IL-6/Lym ratio, IL-6, D-Dimer, D-Dimer/fibrinogen ratio, fibrinogen, C-reactive protein (CRP), lymphocytes count and neutrophil/lymphocyte (N/L) ratio collected at hospital admission were tested as prognosticators of negative outcome, defined as combined endpoint in-hospital mortality and/or Intensive Care Unit (ICU) admission requiring oro-tracheal intubation (OTI). RESULTS: Study population encompassed two hundreds and twenty-three patients (46% females) with mean age ± DS 69.4 ± 13.3 years. Eighty-nine patients (39.9%) suffered for severe respiratory failure and required non invasive ventilation, helmets and/or high flow nasal cannula. Fourty-one patients (18.3%) died during hospital stay and/or required OTI. In these patients mean values of IL-6/Lym ratio, IL-6, CRP and N/L were significantly higher and lymphocytes count was significantly lower compared with patients discharged alive and/or not requiring OTI, while no difference was found in mean values of D-Dimer, D-Dimer/Fibrinogen ratio and fibrinogen. AUC (0.797, 95% CI: 0.738-0.848) of IL-6/Lym ratio was the highest compared with those of all the other analyzed biomarkers and the difference was significant with the exception of IL-6. At multivariate logistic regression IL-6/Lym ratio > 66.5 resulted the only independent biomarker associated with mortality and/or OTI (OR 5.65; 95% 1.63-19.54). CONCLUSION: IL-6/Lym ratio seems to be an optimal prognosticator in SARS-CoV2 related pneumonia. Its routinary use in COVID-19 patients could be warranted.

Patients with Griscelli syndrome and normal pigmentation identify RAB27A mutations that selectively disrupt MUNC13-4 binding.

BACKGROUND: Familial hemophagocytic lymphohistiocytosis (FHL) is a rare and often fatal disorder characterized by defective cellular cytotoxicity and hyperinflammation, and the only cure known to date is hematopoietic stem cell transplantation. Mutations in RAB27A, LYST, and AP3B1 give rise to FHL associated with oculocutaneous albinism, and patients with FHL are usually only screened for mutations in these genes when albinism is observed. A number of patients with FHL and normal pigmentation remain without a genetic diagnosis. OBJECTIVE: We asked whether patients with FHL with immunodeficiency but with normal pigmentation might sometimes have mutations that affected cellular cytotoxicity without affecting pigmentation. METHODS: We carried out mutation analysis of RAB27A, LYST, and AP3B1 in patients with FHL with pigment dilution, as well as a cohort with no clinical evidence of pigment dilution but no mutations in the other known FHL-related genes (PRF1, STXBP2, and UNC13D). RESULTS: We identify patients with Griscelli syndrome type 2 with biallelic mutations in RAB27A in the absence of albinism. All 6 patients carried mutations at amino acids R141, Y159, or S163 of Rab27a that disrupt the interaction of Rab27a with Munc13-4, without impairing the interaction between melanophilin and Rab27a. CONCLUSION: These studies highlight the need for RAB27A sequencing in patients with FHL with normal pigmentation and identify a critical binding site for Munc13-4 on Rab27a, revealing the molecular basis of this interaction.

Familial hemophagocytic lymphohistiocytosis: when rare diseases shed light on immune system functioning.

The human immune system depends on the activity of cytotoxic T lymphocytes (CTL), natural killer (NK) cells, and NKT cells in order to fight off a viral infection. Understanding the molecular mechanisms during this process and the role of individual proteins was greatly improved by the study of familial hemophagocytic lymphohistiocytosis (FHL). Since 1999, genetic sequencing is the gold standard to classify patients into different subgroups of FHL. The diagnosis, once based on a clinical constellation of abnormalities, is now strongly supported by the results of a functional flow-cytometry screening, which directs the genetic study. A few additional congenital immune deficiencies can also cause a resembling or even identical clinical picture to FHL. As in many other rare human disorders, the collection and analysis of a relatively large number of cases in registries is crucial to draw a complete picture of the disease. The conduction of prospective therapeutic trials allows investigators to increase the awareness of the disease and to speed up the diagnostic process, but also provides important functional and genetic confirmations. Children with confirmed diagnosis may undergo hematopoietic stem cell transplantation, which is the only cure known to date. Moreover, detailed characterization of these rare patients helped to understand the function of individual proteins within the exocytic machinery of CTL, NK, and NKT cells. Moreover, identification of these genotypes also provides valuable information on variant phenotypes, other than FHL, associated with biallelic and monoallelic mutations in the FHL-related genes. In this review, we describe how detailed characterization of patients with genetic hemophagocytic lymphohistiocytosis has resulted in improvement in knowledge regarding contribution of individual proteins to the functional machinery of cytotoxic T- and NK-cells. The review also details how identification of these genotypes has provided valuable information on variant phenotypes.

Monoallelic mutations of the perforin gene may represent a predisposing factor to childhood anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) accounts for approximately 15% of all pediatric non-Hodgkin lymphomas. It has distinct clinical features, including frequent involvement of extranodal sites and rare localization to the central nervous system. As some presenting features of ALCL are in common with the hemophagocytic syndrome, we previously analyzed a small series of patients with ALCL for PRF1 mutations and found that 27% of them carried mutations. We now expanded our preliminary study by increasing the cohort of ALCL patients to a total of 84 consecutive cases, in whom we extended mutation analysis to the genes SH2D1A, PRF1 e UNC13D, all related to familial HLH. Furthermore, perforin expression in tumor cells was investigated on paraffin-embedded tissues by immunohistochemical analysis. Mutations were observed in 23/84 patients (27.4%). Twenty-one patients (25%) carried a total of 10 different mutations of PRF1; they were monoallelic in 20 patients, biallelic in 1. No mutations were found in the gene SH2D1A. Two additional patients had missense mutations of the UNC13D gene. These data show that monoallelic germline mutations of PRF1 are frequent in patients with childhood ALCL, suggesting that partially impaired cytotoxic machinery may represent a predisposing factor for ALCL. Involvement is less frequent for UNC13D and absent for SH2D1A.

Genotype-phenotype study of familial haemophagocytic lymphohistiocytosis type 3.

BACKGROUND: Mutations of UNC13D are causative for familial haemophagocytic lymphohistiocytosis type 3 (FHL3; OMIM 608898). OBJECTIVE: To carry out a genotype-phenotype study of patients with FHL3. METHODS: A consortium of three countries pooled data on presenting features and mutations from individual patients with biallelic UNC13D mutations in a common database. RESULTS: 84 patients with FHL3 (median age 4.1 months) were reported from Florence, Italy (n=54), Hamburg, Germany (n=18), Stockholm, Sweden (n=12). Their ethnic origin was Caucasian (n=57), Turkish (n=10), Asian (n=7), Hispanic (n=4), African (n=3) (not reported (n=3)). Thrombocytopenia was present in 94%, splenomegaly in 96%, fever in 89%. The central nervous system (CNS) was involved in 49/81 (60%) patients versus 36% in patients with FHL2 (p=0.001). A combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia was present in 71%. CD107a expression, NK activity and Munc 13-4 protein expression were absent or reduced in all but one of the evaluated patients. 54 different mutations were observed, including 15 new ones: 19 missense, 14 deletions or insertions, 12 nonsense, nine splice errors. None was specific for ethnic groups. Patients with two disruptive mutations were younger than patients with two missense mutations (p<0.001), but older than comparable patients with FHL2 (p=0.001). CONCLUSION: UNC13D mutations are scattered over the gene. Ethnic-specific mutations were not identified. CNS involvement is more common than in FHL2; in patients with FHL3 and disruptive mutations, age at diagnosis is significantly higher than in FHL2. The combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia appears to be the most easily and frequently recognised clinical pattern and their association with defective granule release assay may herald FHL3.

Endometrial cancer and somatic G>T KRAS transversion in patients with constitutional MUTYH biallelic mutations.

MUTYH-associated polyposis (MAP) is an autosomal recessive condition predisposing to colorectal cancer, caused by constitutional biallelic mutations in the base excision repair (BER) gene MUTYH. Colorectal tumours from MAP patients display an excess of somatic G>T mutations in the APC and KRAS genes due to defective BER function. To date, few extracolonic manifestations have been observed in MAP patients, and the clinical spectrum of this condition is not yet fully established. Recently, one patient with a diagnosis of endometrial cancer and biallelic MUTYH mutations has been described. We here report on two additional unrelated MAP patients with biallelic MUTYH germline mutations who developed endometrioid endometrial carcinoma. The endometrial tumours were evaluated for PTEN, PIK3CA, KRAS, BRAF and CTNNB1 mutations. A G>T transversion at codon 12 of the KRAS gene was observed in one tumour. A single 1bp frameshift deletion of PTEN was observed in the same sample. Overall, these findings suggest that endometrial carcinoma is a phenotypic manifestations of MAP and that inefficient repair of oxidative damage can be involved in its pathogenesis.