Stability and heterogeneity in the antimicrobiota reactivity of human milk-derived immunoglobulin A

Immunoglobulin A (IgA) is secreted into breast milk and is critical for both protecting against enteric pathogens and shaping the infant intestinal microbiota. The efficacy of breast milk-derived maternal IgA (BrmIgA) is dependent upon its specificity; however, heterogeneity in BrmIgA binding ability to the infant microbiota is not known. Using a flow cytometric array, we analyzed the reactivity of BrmIgA against bacteria common to the infant microbiota and discovered substantial heterogeneity between all donors, independent of preterm or term delivery. Surprisingly, we also observed intradonor variability in the BrmIgA response to closely related bacterial isolates. Conversely, longitudinal analysis showed that the antibacterial BrmIgA reactivity was relatively stable through time, even between sequential infants, indicating that mammary gland IgA responses are durable. Together, our study demonstrates that the antibacterial BrmIgA reactivity displays interindividual heterogeneity but intraindividual stability. These findings have important implications for how breast milk shapes the development of the preterm infant microbiota and protects against necrotizing enterocolitis.

Understanding the Burden of Kidney Failure in Trinidad and Tobago: A Review of the Epidemiological Data From a Regional Center

Objective The aim of this study was to determine the incidence of new patients requiring renal replacement therapy and to gather data on sex, age, ethnicity, mortality, and causes of kidney failure in Trinidad and Tobago in comparison with the rest of the world. Method Electronic data were gathered for new patients initiating dialysis between January 1, 2016, and December 31, 2017, including the date of dialysis initiation, age, gender, ethnicity, diagnosis, dialysis access and modality, and outcome at three months and the end of the year. The data were analyzed using simple descriptive statistics via Microsoft Excel (Microsoft Corporation, Redmond, Washington, United States). Results Over a two-year period, 265 new patients underwent renal replacement therapy, of which 51.7% were 50-69 years of age, 53.9% were male, 46% were female, 67.9% were Afro-Trinidadian, and 38.1% had a combination of diabetes mellitus and hypertension as the cause of kidney failure. The incidence rates of treated end-stage renal disease (ESRD) globally in 2016 and 2017 were 306 and 224 per million population, respectively, and mortality for both years was 32% and 32.1%, respectively. Conclusion Our study showed that Trinidad and Tobago has one of the highest incidences of patients initiating renal replacement therapy and mortality rates.

Stability and heterogeneity in the anti-microbiota reactivity of human milk-derived Immunoglobulin A

Immunoglobulin A (IgA) is secreted into breast milk and is critical to both protecting against enteric pathogens and shaping the infant intestinal microbiota. The efficacy of breast milk-derived maternal IgA (BrmIgA) is dependent upon its specificity, however heterogeneity in BrmIgA binding ability to the infant microbiota is not known. Using a flow cytometric array, we analyzed the reactivity of BrmIgA against bacteria common to the infant microbiota and discovered substantial heterogeneity between all donors, independent of preterm or term delivery. We also observed intra-donor variability in the BrmIgA response to closely related bacterial isolates. Conversely, longitudinal analysis showed that the anti-bacterial BrmIgA reactivity was relatively stable through time, even between sequential infants, indicating that mammary gland IgA responses are durable. Together, our study demonstrates that the anti-bacterial BrmIgA reactivity displays inter-individual heterogeneity but intra-individual stability. These findings have important implications for how breast milk shapes the development of the infant microbiota and protects against Necrotizing Enterocolitis.

SUMMARY

We analyze the ability of breast milk-derived Immunoglobulin A (IgA) antibodies to bind the infant intestinal microbiota. We discover that each mother secretes into their breast milk a distinct set of IgA antibodies that are stably maintained over time.

Antioxidants and/or fish oil reduce intermittent hypoxia-induced inflammation in the neonatal rat terminal ileum

Intermittent hypoxia (IH) is associated with the pathogenesis of necrotizing enterocolitis (NEC). We tested the hypothesis that early supplementation with antioxidants and/or fish oil protects the terminal ileum from oxidative injury induced by neonatal IH. Newborn rats were exposed to neonatal IH from birth (P0) until P14 during which they received daily fish oil, coenzyme Q10 (CoQ10), glutathione nanoparticles (nGSH), fish oil + CoQ10, or olive oil. Pups were then placed in room air from P14 to P21 with no further supplementation. Terminal ileum was assessed for IH-induced injury and inflammatory biomarkers. Neonatal IH induced severe damage consistent with NEC, and was associated with oxidative stress and elevations in PGE₂, PGF_2α, TxB₂, NOS-2 and TLR-4, effects that were ameliorated with nGSH and combination CoQ10+fish oil. Early postnatal supplementation with antioxidants and/or fish oil during neonatal IH may be favorable for preserving gut integrity and reducing oxidative injury.

Effects of omega 3 polyunsaturated fatty acids, antioxidants, and/or non-steroidal inflammatory drugs in the brain of neonatal rats exposed to intermittent hypoxia

Preterm infants experience frequent arterial oxygen desaturations during oxygen therapy, or intermittent hypoxia (IH). Neonatal IH increases oxidative distress which contributes to neuroinflammation and brain injury. We tested the hypotheses that exposure to neonatal IH is detrimental to the immature brain and that early supplementation with antioxidants and/or omega 3 polyunsaturated fatty acids (n-3 PUFAs) combined with non-steroidal anti-inflammatory drugs (NSAIDs) is protective. Newborn rats were exposed to brief hypoxia (12% O₂ ) during hyperoxia (50% O₂ ) from the first day of life (P0) until P14 during which they received daily oral supplementation with antioxidants, namely coenzyme Q10 (CoQ10) or glutathione nanoparticles (nGSH), n-3 PUFAs and/or topical ocular ketorolac. Placebo controls received daily oral olive oil and topical ocular saline. Room air (RA) littermates remained in 21% O₂ from birth to P21 with all treatments identical. At P14 animals were allowed to recover in RA until P21 with no further treatment. Whole brains were harvested for histopathology and morphometric analyses, and assessed for biomarkers of oxidative stress and inflammation, as well as myelin injury. Neonatal IH resulted in higher brain/body weight ratios, an effect that was reversed with n-3 PUFAs and n-3 PUFAs+CoQ10 with or without ketorolac. Neonatal IH was also associated with hemorrhage, oxidative stress, and elevations in inflammatory prostanoids. Supplementation with n-3 PUFAs and nGSH with and without ketorolac were most beneficial for myelin growth and integrity when administered in RA. However, the benefit of n-3 PUFAs was significantly curtailed in neonatal IH. Neonatal IH during a critical time of brain development causes inflammation and oxidative injury. Loss of therapeutic benefits of n-3 PUFAs suggest its susceptibility to oxidation in neonatal IH and therefore indicate that co-administration with antioxidants may be necessary to sustain its efficacy.

Gemcitabine/platinum alone or in combination with cetuximab as first-line treatment for advanced non-small cell lung cancer (NSCLC)

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Background: This randomized phase II study was conducted to evaluate the benefit of adding cetuximab, an IgG1 monoclonal antibody targeting the EGF receptor, to gemcitabine/platinum chemotherapy in patients with recurrent or metastatic NSCLC. Methods: Patients with previously untreated stage IIIB (malignant pleural effusion) or stage IV NSCLC irrespective of their EGF receptor status were eligible for this study. Patients on arm A received cetuximab (400 mg/m2 IV on day 1 followed by 250 mg/m2 weekly) combined with either cisplatin (75 mg/m2 IV q3 weeks) and gemcitabine (1,250 mg/m2 IV days 1 and 8) or carboplatin (AUC 5 IV q3 weeks) and gemcitabine (1,000 mg/m2 IV days 1 and 8). Patients on Arm B received the same chemotherapy regimen without cetuximab. The primary endpoint was tumor response rate with progression-free (PFS) and overall survival (OS) as secondary endpoints. Results: 73 women and 58 men, median age 66 years (35–88) were randomized to arm A (n=65) or arm B (n=66). Partial responses occurred in 18 (27.7%, 95% CI: 17.3–40.2) patients in arm A and 12 (18.2%, 95% CI 9.8–29.6) in arm B. Median PFS was 5.09 months for arm A (95% CI: 4.17–5.98) and 4.21 months (95% CI: 3.81–5.49) in arm B; median OS was 11.99 (95% CI: 8.80–15.20) and 9.26 months (95% CI: 7.43–11.79) respectively. The incidence of drug related infusion reactions (any grade) in arm A was 15.6% and 1.5% in arm B. Three patients in arm A had grade 3–4 cetuximab related infusion reactions. Severe acneform rash was observed in 14.1% of patients in arm A and none in arm B. Other toxicities were similar and only 18.5% of patients in arm A and 10.6% patients in arm B discontinued treatment for toxicity. Conclusions: These data confirm the previously observed benefit for the combination of cetuximab with a platinum based doublet chemotherapy regimen patients with metastatic NSCLC. The difference of 2.7 months in median OS between treatment arms seems to suggest a more substantial clinical benefit. Fully powered phase III studies addressing this question are on- going and results will become available in 2007.

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Randomized phase II trial of single agent erlotinib vs. standard chemotherapy in patients with advanced non-small cell lung cancer (NSCLC) and performance status (PS) of 2

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Background: A previous CALGB trial suggested a benefit for carboplatin-paclitaxel (CP) over P alone in pts with PS 2. Erlotinib (E) has activity in previously treated pts with low PS but has not been formally tested in 1st line. Methods: In a multi-center randomized phase II trial, untreated pts with advanced NSCLC and PS 2 were randomized to E 150 mg daily or CP (AUC 6 and 200 mg/m2) for 4 cycles. Pts in CP who progressed, did not tolerate, or refused further therapy were allowed to cross over to E. The primary endpoint was progression-free survival (PFS). QoL analysis was performed in all pts and tumor samples were obtained whenever possible. Results: As of 12/05, 98 of 102 projected pts have been accrued. Results are reported for 88 (46 E; 42 CP). Demographics were balanced except for more females in E (59%) than CP (45%). Most pts had stage IV adenoca histology. Never-smokers comprised 13% and 7% of pts respectively. Response for E: 2% PR and 30% SD; for CP, 10% PR and 45% SD. Gr 2–4 toxicities for E: rash (34%) and diarrhea (11%); for CP: nausea (12%), neuropathy (14%) and fatigue (29%). Median PFS was 2.5 mo for E (95%CI 1.28 - 2.79) and 4.0 mo for CP (95%CI 2.66 - 4.86). Of 42 pts in CP, 21 have crossed over to E. Conclusions: This is the first randomized phase II trial of E in PS 2 patients. Based on preliminary results, PS 2 patients seemed to fare better with standard CP than single agent E as initial therapy. Mature survival and QoL data will be available in June.

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ZD6474 versus gefitinib in patients with advanced NSCLC: Final results from a two-part, double-blind, randomized phase II trial

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Background: ZD6474 is a once-daily oral agent that targets key signaling pathways in cancer by inhibiting VEGF, EGF and RET receptor tyrosine kinase activity. The efficacy and safety of ZD6474 was compared with that of gefitinib, an EGFR tyrosine kinase inhibitor. Methods: Patients with locally advanced or metastatic (stage IIIB/IV) non-small-cell lung cancer (NSCLC), after failure of 1st-line ± 2nd-line platinum-based chemotherapy because of toxicity or tumor progression, received daily oral doses of ZD6474 (300 mg) or gefitinib (250 mg) until disease progression or evidence of toxicity (Part A). After a washout period of 4 weeks, eligible patients had the option to switch to the alternative treatment, which continued until a withdrawal criterion was met (Part B). The dual primary objectives in Part A were assessments of progression-free survival (PFS) and safety/tolerability. All adverse events were assessed using Common Toxicity Criteria (CTC) version 2.0. Results: A total of 168 patients received initial treatment with ZD6474 (n=83) or gefitinib (n=85). In Part A, median PFS was 11.0 weeks for ZD6474 and 8.1 weeks for gefitinib (hazard ratio [95% CI] = 0.69 [0.50–0.96], P=0.025); disease control >8 weeks was achieved in 37/83 (45%) patients receiving ZD6474 and in 29/85 (34%) receiving gefitinib. The adverse event profile of ZD6474 in Part A was similar to that seen in previous trials, and included diarrhea (CTC grade 3/4, 8.4%), rash (CTC grade 3/4, 4.8%) and asymptomatic QTc prolongation (all CTC grade 1, 20.5%). There were no unexpected safety findings with gefitinib-treated patients. In Part B, disease control >8 weeks was achieved in 16/37 patients who switched to ZD6474 (from gefitinib) and in 7/29 who switched to gefitinib (from ZD6474). Overall survival was not significantly different between patients initially randomized to either ZD6474 or gefitinib (median 6.1 and 7.4 months, respectively). Conclusions: This study achieved its primary efficacy objective, with ZD6474 demonstrating a significant prolongation of PFS versus gefitinib. These data support further confirmatory trials of ZD6474 in patients with advanced NSCLC.

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IDEC-C2B8 (Rituximab) anti-CD20 monoclonal antibody therapy in patients with relapsed low-grade non-Hodgkin's lymphoma

IDEC-C2B8 is a chimeric monoclonal antibody (MoAb) directed against the B-cell-specific antigen CD20 expressed on non-Hodgkin's lymphomas (NHL). The MoAb mediates complement and antibody-dependent cell-mediated cytotoxicity and has direct antiproliferative effects against malignant B-cell lines in vitro. Phase I trials of single doses up to 500 mg/m2 and 4 weekly doses of 375 mg/m2 showed clinical responses with no dose-limiting toxicity. We conducted a phase II, multicenter study evaluating four weekly infusions of 375 mg/m2 IDEC-C2B8 in patients with relapsed low-grade or follicular NHL (Working Formulation groups A-D). Patients were monitored for adverse events, antibody pharmacokinetics, and clinical response. Thirty-seven patients with a median age of 58 years (range, 29 to 81 years) were treated. All patients had relapsed after chemotherapy (median of 2 prior regimens) and 54% had failed aggressive chemotherapy. Infusional side effects (grade 1-2) consisting of mild fever, chills, respiratory symptoms, and occasionally hypotension were observed mostly with the initial antibody infusion and were rare with subsequent doses. Peripheral blood B-cell depletion occurred rapidly, with recovery beginning 6 months posttreatment. There were no significant changes in mean IgG levels and infections were not increased over what would be expected in this population. Clinical remissions were observed in 17 patients (3 complete remissions and 14 partial remissions), yielding an intent to treat response rate of 46%. The onset of these tumor responses was as soon as 1 month posttreatment and reached a maximum by 4 months posttreatment. In the 17 responders, the median time to progression was 10.2 months (5 patients exceeding 20 months). Likelihood of tumor response was associated with a follicular histology, with the ability to sustain a high serum level of antibody after the first infusion, and with a longer duration of remission to prior chemotherapy. One patient developed a detectable but not quantifiable immune response to the antibody that had no clinical significance. IDEC-C2B8 in a dose of 375 mg/m2 weekly for 4 weeks has antitumor activity in patients with relapsed low-grade or follicular NHL. Results with this brief, outpatient treatment compare favorably with results with standard chemotherapy, and IDEC-C2B8 has a better safety profile. Further studies evaluating IDEC-C2B8 in other types of lymphoma either alone or combined with chemotherapy are warranted.

Molecular analysis of Polish patients with factor VII deficiency

We analyzed the mutations in patients from 10 Polish kindreds with a bleeding diathesis due to factor VII deficiency. Patients from eight families had plasma levels of factor VII coagulant activity (VII:C) and factor VII antigen (VII:Ag) that were less than 4% of normal. The coding sequence of the factor VII gene was amplified from genomic DNA by polymerase chain reaction (PCR). Sequencing demonstrated a C to T transition at position 10798 resulting in Ala294Val, a G to A transition at 10976 resulting in Arg353Gln, and a single bp deletion at 11125 to 11128 causing a frameshift mutation in the triplet encoding amino acid 404. Homozygosity for the three sequence alterations was confirmed with the restriction enzymes AvaII and MspI and allele specific PCR, respectively. A homozygous patient from a ninth family with levels of VII:C and VII:Ag of 4% and 17%, respectively, had Ala294Val and the frameshift mutation, but not Arg353Gln. Investigation of a homozygous patient from a tenth kindred with VII:C and VII:Ag of 11% and 47%, respectively, demonstrated Ala294Val and Arg353Gln, but not the frameshift mutation. Based on the above data, we conclude that the frameshift mutation in the codon for amino acid 404 is associated with marked reductions in VII:C, Arg353Gln can decrease plasma levels of factor VII in the presence of other mutations in the factor VII gene, and Ala294Val results in a dysfunctional factor VII molecule.

Comparison of antibody concentrations and protective activity of respiratory syncytial virus immune globulin and conventional immune globulin

Relative to conventional immune globulins (IG, 13 lots), IGs prepared from donors with high activity by microneutralization assay to respiratory syncytial virus (RSVIG, 8 lots) had significantly higher neutralizing antibodies to 6 RSV strains (mean enrichment, 5.2-fold; range, 2.6- to 10.0-fold). In contrast, IgG antibody concentrations to whole RSV, fusion protein, or glycoproteins of A and B strains were similar in RSVIG and IG. Treatment of cotton rats with RSVIG at 0.5 g/kg 24 h before RSV challenge reduced RSV by 99% in the lungs (P < .001). RSVIG at 5.0 g/kg reduced RSV by 99% in the nose. IG at 5.0 g/kg had efficacy similar to that of RSVIG at 0.5 g/kg. Serum plaque-reduction neutralization titers of 1/390 resulted in 99% reduction of lung RSV and titers of 1/3500 resulted in 99% reduction in nose RSV. Relative to IG, RSVIG is enriched selectively in RSV neutralizing antibodies and has approximately 10 times greater protective activity in cotton rats.

Intraluminal proteolytic activation plays an important role in replication of type 1 reovirus in the intestines of neonatal mice

Oral inoculation of suckling mice with reovirus serotype 1 (strain Lang) results in the conversion of intact virions to intermediate subviral particles (ISVPs) in the intestinal lumen. Digestion of virus in vitro with chymotrypsin or trypsin reveals two distinct forms of ISVPs, while the predominant species of ISVPs found in the small intestinal lumen appears to be identical to the chymotrypsin product. The in vivo conversion of virions to ISVPs was blocked by pretreatment of mice with protease inhibitors, resulting in inefficient replication of reovirus in intestinal tissue. The early inhibition of viral replication in suckling mice pretreated with protease inhibitors was not observed when suckling mice were inoculated with ISVPs generated by in vitro digestion with either chymotrypsin or trypsin. However, replication was decreased during secondary rounds of replication in mice receiving repeated doses of protease inhibitors, suggesting that luminal proteolytic digestion is important in rendering progeny virions infectious in the gut.