Germline variants of uncertain significance, their frequency, and clinico-pathological features in a cohort of Sri Lankan patients with hereditary breast cancer

BACKGROUND

Next-Generation Sequencing (NGS)-based testing in cancer patients has led to increased detection of variants of uncertain significance (VUS). VUS are genetic variants whose impact on protein function is unknown. VUS pose a challenge to clinicians and patients due to uncertainty regarding their cancer predisposition risk. Paucity of data exists on the pattern of VUS in under-represented populations. This study describes the frequency of germline VUS and clinico-pathological features in Sri Lankan hereditary breast cancer patients.

METHODS

Data of 72 hereditary breast cancer patients who underwent NGS-based testing between January 2015 and December 2021 were maintained prospectively in a database and analyzed retrospectively. Data were subjected to bioinformatics analysis and variants were classified according to international guidelines.

RESULTS

Germline variants were detected in 33/72(45.8%) patients, comprising 16(48.5%) pathogenic/likely pathogenic variants and 17(51.5%) VUS. Distribution of VUS in breast cancer predisposing genes were :APC:1(5.8%), ATM:2(11.7%), BRCA1:1(5.8%), BRCA2:5(29.4%), BRIP1:1(5.8%), CDKN2A:1(5.8%), CHEK2:2(11.7%), FANC1:1(5.8%), MET:1(5.8%), STK11:1(5.8%), NF2:1(5.8%). Mean age at cancer diagnosis in patients with VUS was 51.2 years. Most common tumour histopathology was ductal carcinoma 11(78.6%). 50% of tumours in patients having VUS in BRCA1/2 genes were hormone receptor negative. 73.3% patients had family history of breast cancer.

CONCLUSIONS

A significant portion of patients had a germline VUS. Highest frequency was in BRCA2 gene. Majority had family history of breast cancer. This highlights the need to undertake functional genomic studies to determine the biological effects of VUS and identify potentially clinically actionable variants that would be useful for decision-making and patient management.

The first genetically authenticated case of Leber hereditary optic neuropathy in Sri Lanka: a case report and review of the literature

INTRODUCTION

Leber hereditary optic neuropathy is a genetic disease of mitochondrial inheritance characterized by bilateral irreversible vision loss, predominantly affecting males. We report the first genetically authenticated Sri Lankan case of Leber hereditary optic neuropathy, illustrating its characteristic features of male predominance and variable penetrance.

CASE PRESENTATION

A 15-year-old previously healthy Sri Lankan boy presented with painless progressive vision loss in his right eye, followed by vision loss in his left eye within 3 months. There was no history of drug or toxin exposure, or a family history of vision loss. His parents were nonconsanguineous. On examination, he could only perceive light. Funduscopy revealed bilateral optic atrophy. Routine hematological and biochemical blood tests, including inflammatory markers, were normal. Cranial magnetic resonance imaging was unremarkable. Optical coherence tomography, and the clinical presentation, suggested a diagnosis of Leber hereditary optic neuropathy, which was confirmed by detection of m.14484T > C pathogenic variant in the MT-ND6 gene through targeted genetic analysis for the three common pathogenic variants in mitochondrial deoxyribonucleic acid. He was homoplasmic for the variant, and his asymptomatic mother and two female siblings were also found to be harboring the variant with homoplasmy.

CONCLUSIONS

This case report is intended to increase awareness of Leber hereditary optic neuropathy, and highlights the need to consider this rare diagnosis in the appropriate clinical context. It also illustrates the phenomena of incomplete penetrance and male predominance, and suggests the possibility of an X-linked gene governing Leber hereditary optic neuropathy disease expression, which warrants further investigation.

Multi-system Klebsiella sepsis: A tale of destruction form lung to eye

Klebsiella pneumoniae, found in the gastrointestinal flora is a causative agent of hospital-acquired infections. Although isolated organ infections are common, reports of multi-system involvement are rare. We report on a susceptible patient presenting with disseminated Klebsiella infection with concurrent multi-organ disease involving the lung, liver, prostate and eye. He recovered after prolonged therapy but suffered from permanent sequalae. Early diagnosis and aggressive therapy is facilitated by awareness and a high degree of suspicion in at-risk patient groups.

Tuberculosis presenting as arthritis of the ankle: A case report

Tuberculosis presenting as monoarticular involvement in immunocompetent patients is rare. Here, we report a Sri Lankan patient presenting with ankle swelling due to tuberculosis with no other extrapulmonary or pulmonary involvement. Magnetic resonance imaging showed destruction of articular cartilage of the ankle joint with chronic inflammation of the subtalar joint. The diagnosis was confirmed by synovial tissue culture which was positive for Mycobacterium tuberculosis. The patient recovered uneventfully with anti-tuberculosis treatment. Therefore, a high degree of suspicion is necessary to diagnose extrapulmonary tuberculosis when patients are presenting with atypical monoarthritis.

Strong dose response after immunotherapy with PQ grass using conjunctival provocation testing

Background

Pollinex Quattro Grass (PQ Grass) is an effective, well-tolerated, short pre-seasonal subcutaneous immunotherapy to treat seasonal allergic rhinoconjunctivitis (SAR) due to grass pollen. In this Phase II study, 4 cumulative doses of PQ Grass and placebo were evaluated to determine its optimal cumulative dose.

Methods

Patients with grass pollen-induced SAR were randomised to either a cumulative dose of PQ Grass (5100, 14400, 27600 and 35600 SU) or placebo, administered as 6 weekly subcutaneous injections over 31-41 days (EudraCT number 2017-000333-31). Standardized conjunctival provocation tests (CPT) using grass pollen allergen extract were performed at screening, baseline and post-treatment to determine the total symptom score (TSS) assessed approximately 4 weeks after dosing. Three models were pre-defined (Emax, logistic, and linear in log-dose model) to evaluate a dose response relationship.

Results

In total, 95.5% of the 447 randomized patients received all 6 injections. A highly statistically significant (p < 0.0001), monotonic dose response was observed for all three pre-specified models. All treatment groups showed a statistically significant decrease from baseline in TSS compared to placebo, with the largest decrease observed after 27600 SU (p < 0.0001). The full course of 6 injections was completed by 95.5% of patients. Treatment-emergent adverse events were similar across PQ Grass groups, and mostly mild and transient in nature.

Conclusions

PQ Grass demonstrated a strong curvilinear dose response in TSS following CPT without compromising its safety profile.

Randomized controlled trials define shape of dose response for Pollinex Quattro Birch allergoid immunotherapy

BACKGROUND

The Birch Allergoid, Tyrosine Adsorbate, Monophosphoryl Lipid A (POLLINEX^® Quattro Plus 1.0 ml Birch 100%) is an effective, well-tolerated short course subcutaneous immunotherapy. We performed 2 phase II studies to determine its optimal cumulative dose.

METHODS

The studies were conducted in Germany, Austria and Poland (EudraCT numbers: 2012-004336-28 PQBirch203 and 2015-000984-15 PQBirch204) using a wide range of cumulative doses. In both studies, subjects were administered 6 therapy injections weekly outside the pollen season. Conjunctival Provocation Tests were performed at screening, baseline and 3-4 weeks after completing treatment, to quantify the reduction in Total Symptom Scores (as the primary endpoint) with each cumulative dose. Multiple Comparison Procedure and Modeling analysis was used to test for the dose response, shape of the curve and estimation of the median effective dose (ED₅₀ ), a measure of potency.

RESULTS

Statistically significant dose responses (P < .01 & .001) were seen, respectively. The highest cumulative dose in PQBirch204 (27 300 standardized units [SU]) approached a plateau. Potency of the PQBirch was demonstrated by an ED₅₀ 2723 SU, just over half the current dose. Prevalence of treatment-emergent adverse events was similar for active doses, most being short-lived and mild. Compliance was over 85% in all groups.

CONCLUSION

Increasing the cumulative dose of PQBirch 5.5-fold from 5100 to 27 300 SU achieved an absolute point difference from placebo of 1.91, a relative difference 32.3% and an increase in efficacy of 50%, without compromising safety. The cumulative dose response was confirmed to be curvilinear in shape.

The monoterpenes of Artemisia tridentata ssp. vaseyana, Artemisia cana ssp. viscidula and Artemisia tridentata ssp. spiciformis

Monoterpenes from three different members of the Anthemideae family, Artemisia tridentata ssp. vaseyana, Artemisia cana ssp. viscidula and Artemisia tridentata ssp. spiciformis were isolated and their structures determined using spectroscopic techniques. A total of 26 irregular and regular monoterpenes were identified. Among these, 20 had previously been identified in the Anthemideae family. Of the remaining six, four were known, but previously unidentified in this family. 2,2-Dimethyl-6-isopropenyl-2H-pyran, 2,3-dimethyl-6-isopropyl-4H-pyran and 2-isopropenyl-5-methylhexa-trans-3,5-diene-1-ol were isolated from both A. tridentata ssp. vaseyana and A. cana ssp. viscidula. The irregular monoterpene 2,2-dimethyl-6-isopropenyl-2H-pyran has a carbon skeleton analogous to the biologically important triterpene squalene. Two additional irregular monoterpenes, artemisia triene and trans-chrysanthemal were isolated from A. cana ssp. viscidula and lavandulol was isolated from A. tridentata ssp. spiciformis. This is the first time a compound possessing a lavandulyl-skeletal type has been found in the Anthemideae family.

Pharmacokinetics and pharmacodynamics of epoetin alfa once weekly and three times weekly

OBJECTIVE

To compare the pharmacokinetics, pharmacodynamics, and tolerance of epoetin alfa administered subcutaneously (s.c.) once weekly (q.w.) and three times weekly (t.i.w.).

METHODS

An open-label, randomized, parallel-design study was conducted in 36 healthy adults with hemoglobin (Hb) levels of 11.7 14.0 g/dl for women and 13.0-14.8 g/dl for men. Subjects were randomized to epoetin alfa 150 IU/kg s.c. t.i.w. or 40,000 IU s.c. q.w. for 4 weeks. Serum erythropoietin concentrations were measured using a validated enzyme-linked immunosorbent assay (ELISA). Pharmacokinetic parameters [peak serum concentration (Cmax), mean predose trough concentration (Cmin), time to Cmax (tmax), clearance after s.c. administration (CL/F), area under the plasma concentration time curve (AUC), and terminal elimination half-life (t 1/2)] were calculated using model-independent methods. Mean changes from baseline and AUC of percentage reticulocytes, Hb, and total red blood cell (RBC) concentrations over the 1-month study period were calculated.

RESULTS

The Cmax values for serum epoetin alfa q.w. were six times and AUC(0-168) values three times that of the t.i.w. regimen. Time profiles of changes in percentage reticulocytes, Hb, and total RBC over 1 month were similar between regimens. The rate of increase in Hb was similar for the two groups, and both groups exhibited a 3.1-g/dl increase in mean Hb levels from baseline through day 29. Changes in ferritin levels were generally similar between groups and reflected expected use of iron stores for Hb production. Epoetin alfa administered t.i.w. or q.w. was well tolerated and no serious adverse events occurred.

CONCLUSION

The pharmacodynamic responses were equivalent between groups despite expected differences in total erythropoietin exposure. These results indicate that the epoetin alfa 150 IU/kg t.i.w. and 40,000 IU q.w. regimens can be considered clinically equivalent.

Vitamin E and other antioxidants inhibit human prostate cancer cells through apoptosis

BACKGROUND

Many human prostate cancer cells have escaped the apoptotic effects of natural regulators of cell growth such as transforming growth factor betal (TGF beta-1) and tumor necrosis factor (TNF).

METHODS

Prostate cancer cell growth was investigated by treating with antioxidants. DU-145 (androgen-unresponsive), LNCaP (androgen-responsive), and ALVA-101 (androgen moderately responsive) were grown in RPMI-1640 medium supplemented with bovine fetal calf serum and antibiotics, and were treated with various antioxidants for 1-7 days. Cell growth was then determined with the Cell Titer 96 AQ assay, and apoptosis was assessed by cell death detection ELISA, nuclear morphology, and TUNEL techniques.

RESULTS

Cells treated with or without (+/-)-alpha-tocopherol (vitamin E) for 1-7 days at concentrations from 0.078-2.5 microg/ml modestly affected cell growth compared to other antioxidants tested. Tocopherol produced a significant (P < 0.01) inhibition of ALVA-101 and LNCaP (10-24% of control; 0.078-2.5 microg/ml; at 6 days; n = 6). DU-145 cells were not growth-inhibited significantly. However, pyrrolidinedithiocarbamate (PDTC) produced a significant (P < 0.01, n = 6; 17-80% of control; 2.5-20 microg/ml; 1-7 days) inhibition of DU-145 and ALVA-101 cells. A significant (P < 0.01) and maximum inhibition of LNCaP cells occurred at all concentration of PDTC (2. 5-20 microg/ml). A third compound, diethyldithiocarbamic acid (DETC), incubated for 1-7 days, produced a significant dose response suppression of cell growth of DU-145 and ALVA-101 cells (P < 0.01; 14-88% of control; 1.25-80 microg/ml; n = 6). LNCaP cells were inhibited by DETC (P < 0.01; 28% of control; 1.25-80 microg/ml; n = 6). All three antioxidants tested stimulated apoptosis in actively dividing ALVA-101, DU-145, and LNCaP cells (P < 0.01; n = 6), but confluent cells were affected less. Testosterone had additive inhibitory effects when combined with PDTC in ALVA-101 cells; however, the other cell lines were not influenced.

CONCLUSIONS

These results demonstrate that antioxidants modulate human prostate cancer cell proliferation by altering apoptosis in dividing cells, and this necrosis or apoptosis in confluent cells is not as effective.