Expression of CD64 on polymorphonuclear neutrophils in patients with familial Mediterranean fever

Early and Effective Diagnosis of Sepsis Using Flow Cytometry

Objective Sepsis is a major global health issue due to its high death and morbidity rates. To avoid the negative effects of sepsis and decrease mortality, it is vital to diagnose and treat it as soon as possible. Blood cultures can take up to 2 days to give result, and they are not always reliable. According to recent studies, neutrophil CD64 expression might be a sensitive and specific option for assessing sepsis. This study aimed to evaluate the diagnostic performance of a flow cytometry analysis for the expression of neutrophil CD64 in sepsis and its comparison with other standard tests in a tertiary care center.

Materials and Methods Prospective analysis on 40 blood samples from suspected sepsis patients admitted to intensive care units with criteria for the systemic inflammatory response syndrome on presentation was performed for expression of neutrophil CD64, C-reactive protein, procalcitonin, and complete blood count. Ten healthy volunteers were also enrolled in this prospective study. The laboratory results were compared in different groups.

Results The neutrophil CD64 had the highest diagnostic value to differentiate between patients of sepsis and nonsepsis groups with a sensitivity of 100% (95% confidence interval [CI]: 77.19–100%) and 100% (95% CI: 55.32–86.83%); specificity of 90.00% (95% CI: 59.58–99.49%) and 87.24% (95% CI: 66.69–99.61%); and likelihood ratio of 10.00 and 7.84, respectively.

Conclusion The neutrophil CD64 expression provides a more sensitive, specific, and novel marker for the early detection of sepsis in critically ill patients.

Persistent Activation of Innate Immunity in Patients with Primary Antibody Deficiencies

Primary antibody deficiencies (PAD) represent a heterogeneous group of disorders, with common variable immunodeficiency being the most common with clinical significance. The main phenotypic defect resides in the inability of B cells to produce antibodies, and the cornerstone of therapy is immunoglobulin replacement treatment in order to fight infections. However, the management of the other inflammatory manifestations is inadequate, reinforcing the hypothesis that a complex genetic background affecting additional cell populations, such as polymorphonuclear cells (PMN) and monocytes, influences the expression of the clinical phenotype of the disease. In this study, we investigated by flow cytometry in different conditions (resting state, and after isolation and incubation, with and without stimuli) the expression pattern of several markers on PMN and monocytes, indicative of their maturation, capacity for chemotaxis, adhesion, opsonization, migration, and phagocytosis in 25 PAD patients, 12 healthy blood donors, and 4 septic patients. In this context, we also analyzed patients before and after the initiation of replacement treatment, as well as an untreated patient in different clinical conditions. Interestingly, we observed that PAD patients exhibit a chronic activation status of the innate immunity compartment, along with several differences in the expression of activation, maturation, and adhesion markers, with respect to different clinical conditions. Moreover, immunoglobulin replacement treatment had a favorable effect on PMN, as it was expressed by a more mature and less activated phenotype on basal state cells, and an enhanced activation capacity after LPS exposure. Thus, we conclude that PAD patients display a persistent innate immune cell activation, which is probably associated with the chronic inflammatory stress, usually observed in these disorders.

Familial Mediterranean fever: overview of pathogenesis, clinical features and management

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease, and is characterized by recurrent attacks of fever and polyserositis. It is associated with mutations in the MEFV gene encoding pyrin, which result in inflammasome activation and the uncontrolled production of IL-1β. FMF mainly affects individuals originating from the Mediterranean basin; however, a Japanese nationwide survey demonstrated that FMF is not uncommon in Japan. The survey also indicated that Japanese FMF patients are clinically or genetically distinct from Mediterranean FMF patients, suggesting a genotype-phenotype correlation. In Japanese patients with FMF, MEFV exon 10 mutations are associated with the more typical FMF phenotype. Conversely, Japanese FMF patients with mutations in MEFV exons 2 or 3 present with an atypical FMF phenotype. Colchicine is the mainstay of FMF treatment, and its regular use prevents febrile attacks and decreases the long-term risk of AA amyloidosis. However, a minority of FMF patients are colchicine-resistant, and anti-IL-1 treatment has proven beneficial in suppressing inflammation in these patients. Although Japanese FMF patients may develop less severe disease compared with Mediterranean FMF patients, they should nevertheless be treated early to prevent recurrent attacks and the subsequent development of AA amyloidosis.

The role of the neutrophil Fcγ receptor I (CD64) index in diagnosing spontaneous bacterial peritonitis in cirrhotic patients

OBJECTIVE

To investigate the role of the neutrophil Fcγ receptor I (CD64) index in the diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients.

METHODS

A total of 123 cirrhotic patients with ascites who fulfilled the inclusion criteria were enrolled in this study. Ascites and blood samples were collected; the polymorphonuclear neutrophil (PMN) count, bacterial culture, and related laboratory tests were performed. The CD64 index was determined for each sample using flow cytometry.

RESULTS

The neutrophil CD64 index results were significantly higher in cirrhotic patients with SBP than in those without SBP (p<0.001). There was a positive correlation between the neutrophil CD64 index and the PMN count in ascites. In the receiver operating characteristic curve (ROC) analysis, the area under the curve (AUC) was 0.894 (95% confidence interval 0.823-0.964, p<0.001). The optimal cut-off value for the neutrophil CD64 index was 2.02. The sensitivity and specificity of the neutrophil CD64 index for cirrhotic patients with SBP were 80.49% and 93.90%, respectively. The elevated neutrophil CD64 index was down-regulated by antibiotic therapy (p=0.002).

CONCLUSIONS

The neutrophil CD64 index could be used as a sensitive and specific indicator for the diagnosis of SBP in cirrhotic patients with ascites and is also modulated by antibiotic therapy.

Multiple Serum Cytokine Profiling to Identify Combinational Diagnostic Biomarkers in Attacks of Familial Mediterranean Fever

The precise cytokine networks in the serum of individuals with familial Mediterranean fever (FMF) that are associated with its pathogenesis have been unknown. Here, we attempted to identify specific biomarkers to diagnose or assess disease activity in FMF patients. We measured serum levels of 45 cytokines in 75 FMF patients and 40 age-matched controls by multisuspension cytokine array. FMF in "attack" or "remission" was classified by Japan College of Rheumatology-certified rheumatologists according to the Tel Hashomer criteria. Cytokines were ranked by their importance by a multivariate classification algorithm. We performed a logistic regression analysis to determine specific biomarkers for discriminating FMF patients in attack. To identify specific molecular networks, we performed a cluster analysis of each cytokine. Twenty-nine of the 45 cytokines were available for further analyses. Eight cytokines' serum levels were significantly elevated in the FMF attack versus healthy control group. Nine cytokines were increased in FMF attack compared to FMF remission. Multivariate classification algorithms followed by a logistic regression analysis revealed that the combined measurement of IL-6, IL-18, and IL-17 distinguished FMF patients in attack from the controls with the highest accuracy (sensitivity 89.2%, specificity 100%, and accuracy 95.5%). Among the FMF patients, the combined measurement of IL-6, G-CSF, IL-10, and IL-12p40 discriminated febrile attack periods from remission periods with the highest accuracy (sensitivity 75.0%, specificity 87.9%, and accuracy 84.0%). Our data identified combinational diagnostic biomarkers in FMF patients based on the measurement of multiple cytokines. These findings help to improve the diagnostic performance of FMF in daily practice and extend our understanding of the activation of the inflammasome leading to enhanced cytokine networks.

Markedly elevated CD64 expression on neutrophils and monocytes as a biomarker for diagnosis and therapy assessment in Kawasaki disease

OBJECTIVE

Kawasaki disease (KD) is the most commonly encountered inflammatory disease in children. However, its pathogenesis and diagnostic biomarkers have not been fully investigated. We examined the activation of neutrophils and monocytes in KD.

METHODS

We studied the expression of the Fcγ-receptors CD64 and CD16 on neutrophils and monocytes in KD before and after the treatment with intravenous infusion of high dose immunoglobulin (IVIG). Bacterial infections were addressed as well.

RESULTS

CD64 expression on neutrophils and monocytes was dramatically increased at the onset of KD flare-ups, but later decreased just after IVIG. Similarly, CD16-positive monocytes were observed at the onset and were less apparent after therapy. The addition of immunoglobulin did not block the expression of CD64 or CD16 in vitro. Serum G-CSF in the majority of patients, and IFN-γ in some patients, were elevated during flares but decreased after treatment.

CONCLUSION

Our findings demonstrate that remarkable CD64 expression during KD flare-ups may serve as a biomarker for diagnosis. Evaluation of CD64 is also potentially useful for the determination of treatment efficacy in KD.

Coexistence of polymyositis and familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive disease affecting populations surrounding the Mediterranean area. In this case report, we report a Japanese female patient with polymyositis (PM) who presented with periodic fever. Genetic analysis revealed that she had compound heterozygous mutations in exon 2 of the MEFV gene (L110P/E148Q/R202Q). Treatment with colchicines (1.0 mg/day) successfully eliminated febrile attack and normalized the elevated levels of neutrophil CD64 expression, leading to the diagnosis of FMF. The association of FMF and PM has not previously been reported, so we discuss this rare association.

[Clinical aspects of Familial Mediterranean fever]

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent and short duration (1-3 days) of fever, and serositis. Based on the nationwide survey of FMF in Japan, the estimated number of Japanese FMF patients is about three hundred. High grade fever was observed in 95.5%, chest pain in 35.8% abdominal pain in 62.7% and arthritis in 31.3% among Japanese FMF patients. AA amyloidosis was confirmed in 5 patients (3.7%). Colchicine was effective in 91.8% of Japanese FMF patients. A significant number of FMF patients exist in Japan, and early diagnosis and treatments should be required to prevent AA amyloidosis.