Perforin gene mutations in 77 Chinese patients with lymphomas

Genetic lesions and targeted therapy in Hodgkin lymphoma

Hodgkin lymphoma is a special type of lymphoma in which tumor cells frequently undergo multiple genetic lesions that are associated with accompanying pathway abnormalities. These pathway abnormalities are dominated by active signaling pathways, such as the JAK-STAT (Janus kinase-signal transducer and activator of transcription) pathway and the NFκB (nuclear factor kappa-B) pathway, which usually result in hyperactive survival signaling. Targeted therapies often play an important role in hematologic malignancies, such as CAR-T therapy (chimeric antigen receptor T-cell immunotherapy) targeting CD19 and CD22 in diffuse large B-cell lymphoma, while in Hodgkin lymphoma, the main targets of targeted therapies are CD30 molecules and PD1 molecules. Drugs targeting other molecules are also under investigation. This review summarizes the actionable genetic lesions, current treatment options, clinical trials for Hodgkin lymphoma and the potential value of those genetic lesions in clinical applications.

A study of elective genome sequencing and pharmacogenetic testing in an unselected population

BACKGROUND

Genome sequencing (GS) of individuals without a medical indication, known as elective GS, is now available at a number of centers around the United States. Here we report the results of elective GS and pharmacogenetic panel testing in 52 individuals at a private genomics clinic in Alabama.

METHODS

Individuals seeking elective genomic testing and pharmacogenetic testing were recruited through a private genomics clinic in Huntsville, AL. Individuals underwent clinical genome sequencing with a separate pharmacogenetic testing panel.

RESULTS

Six participants (11.5%) had pathogenic or likely pathogenic variants that may explain one or more aspects of their medical history. Ten participants (19%) had variants that altered the risk of disease in the future, including two individuals with clonal hematopoiesis of indeterminate potential. Forty-four participants (85%) were carriers of a recessive or X-linked disorder. All individuals with pharmacogenetic testing had variants that affected current and/or future medications.

CONCLUSION

Our study highlights the importance of collecting detailed phenotype information to interpret results in elective GS.

Comparing hemophagocytic lymphohistiocytosis in pediatric and adult patients

PURPOSE OF REVIEW

Hemophagocytic lymphohistiocytosis (HLH) has long been thought of primarily as a pediatric disease. However, this syndrome may occur secondary to underlying malignancies, infections, and autoimmune diseases, in adult patients. Here, we seek to highlight similarities and differences between pediatric and adult HLH, knowledge gaps, and areas of active research.

RECENT FINDINGS

Malignancy is a more frequent driver of HLH in adults, present in nearly half. Prognosis is poor as compared with nonmalignant HLH. Prognosis in adults is generally worse than pediatric patients, suggesting that age and other comorbid illnesses not surprisingly affect the outcome of HLH. Diagnostic and treatment approaches are more variable in adults, likely contributing to poorer outcomes. The frequency of mutations in HLH-causing genes is higher than had been anticipated in adults, although with a higher frequency of uniallelic and hypomorphic mutations than in children.

SUMMARY

Optimizing diagnostic criteria for earlier detection may benefit both children and adults. Standardizing treatment approaches in adults will be more difficult because of the variability in triggering illnesses, but a more standardized or algorithmic approach will likely be beneficial. More research into the role of uniallelic and hypomorphic mutations in adults is necessary, to understand treatment and prognostic implications.

Perforin gene variation influences survival in childhood acute lymphoblastic leukemia

Although a growing body of data links mutations in the perforin gene with increased susceptibility to hematologic malignancies, no studies discuss their influence on the clinical course of such diseases. The present study examines the impact of perforin gene variation on the clinical outcome in acute lymphoblastic leukemia (ALL) patients. The study enrolled 312 children aged 1-18 years, treated for ALL. PRF1 gene variants were analyzed through direct DNA sequencing. Variation in rs885822 was found to be associated with overall survival: patients carrying the GG genotype demonstrated a significantly increased risk of death compared to those carrying the A allele, independently of ALL risk groups (HR 3.13, 95%CI 1.16-7.8, p = 0.014). The effect was even more pronounced in high-risk ALL patients (p = 0.006). On the other hand, the presence of the rs35947132 minor A allele was slightly protective with regard to overall prognosis (p = 0.047). No differences in relapse-free survival were observed with regard to genotypes. The results of the study may imply that perforin gene variation has a role in modifying mortality in childhood ALL.

Germline mutations predisposing to diffuse large B-cell lymphoma

Genetic studies of diffuse large B-cell lymphomas (DLBCLs) in humans have revealed numerous targets of somatic mutations and an increasing number of potentially relevant germline alterations. The latter often affect genes involved in DNA repair and/or immune function. In general, defects in these genes also predispose to other conditions. Knowledge of these mutations can lead to disease-preventing measures in the patient and relatives thereof. Conceivably, these germline mutations will be taken into account in future therapy of the lymphoma. In other hematological malignancies, mutations originally found as somatic aberrations have also been shown to confer predisposition to these diseases, when occurring in the germline. Further interrogations of the genome in DLBCL patients are therefore expected to reveal additional hereditary predisposition genes. Our review shows that germline mutations have already been described in over one-third of the genes that are somatically mutated in DLBCL. Whether such germline mutations predispose carriers to DLBCL is an open question. Symptoms of the inherited syndromes associated with these genes range from anatomical malformations to intellectual disability, immunodeficiencies and malignancies other than DLBCL. Inherited or de novo alterations in protein-coding and non-coding genes are envisioned to underlie this lymphoma.

Variations of the perforin gene in patients with chronic inflammatory demyelinating polyradiculoneuropathy

Perforin (PRF) has a key role in the function of cytotoxic T and natural killer cells. Rare variations of PRF1 predispose to autoimmunity. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune disease of the peripheral nervous system, involving defective lymphocyte apoptosis. The aim of this study was to investigate the role of PRF1 in CIDP. The entire coding region of PRF1 was sequenced in 94 patients and 158 controls. We found three missense variations leading to amino acid substitutions and one nonsense variation resulting in a premature stop codon. All variations would decrease PRF activity. Their overall frequency was significantly higher in patients than in controls (odds ratio (OR)=4.47). The most frequent variation was p.Ala91Val (OR=3.92) previously associated with other autoimmune diseases. Clinical analysis showed that PRF1 variations were more frequent in relapsing patients and in patients displaying axonal damage. These data suggest that PRF1 variations may influence CIDP development and course.