Brandon Lam - Academia.edu (original) (raw)

Papers by Brandon Lam

Research paper thumbnail of Detection of High and Low-Affinity Antibodies Against a Human Monoclonal Antibody Using Various Technology Platforms

Assay and Drug Development Technologies, 2007

The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunoso... more The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and electrochemiluminescence (ECL) methods was evaluated using a panel of murine mAbs with affinities ranging from 0.057 to 340 nM. M1 and M7 are anti-idiotypic mAbs against a human mAb, ABX10, with dissociation equilibrium constant (KD) values of 0.057 and 7.2 nM, respectively. HP6030 and HP6002 are anti human IgG mAbs with KD values of 30 and 340 nM, respectively. The limit of detection (LOD) for these mAbs was determined using ELISA, SPR, and ECL technologies and was generally correlated with the rank order of their affinities. The LODs for M1, M7, HP6030, and HP6002 by ELISA were 17 +/- 13, 26,000 +/- 9,020, 344,000 +/- 271,000, and 792,000 +/- 1,050,000 ng/ml, respectively. According to an industry-suggested detection limit of 500 ng/ml, the ELISA was not sensitive enough for detecting M7, HP6030, and HP6002, demonstrating its limitation for detection of low- affinity mAbs. The SPR method lowered the LOD for M7 to 3,900 ng/ml, which was above the industry requirement. The ECL method lowered the LOD for all antibodies tested. Importantly, the ECL method lowered the LOD for M7 to 570 +/- 370 ng/ml, which is close to the industry requirement. Since the ECL method had demonstrated a high serum tolerance, its detection capability may be improved by using a higher percentage of serum in the assay matrix. Although a hook effect was observed with ECL methods, the methods could still detect anti-drug antibody (ADA) concentrations greater than 1 mg/ml, which minimizes concerns that high-titer ADA responses could be missed. The results demonstrated the superiority of an ECL method in detecting high- and low- affinity antibodies when compared to the ELISA and SPR methods.

Research paper thumbnail of Detection of High- and Low-Affinity Antibodies Against a Human Monoclonal Antibody Using Various Technology Platforms

ASSAY and Drug Development Technologies, 2007

The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunoso... more The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and electrochemiluminescence (ECL) methods was evaluated using a panel of murine mAbs with affinities ranging from 0.057 to 340 nM. M1 and M7 are anti-idiotypic mAbs against a human mAb, ABX10, with dissociation equilibrium constant (KD) values of 0.057 and 7.2 nM, respectively. HP6030 and HP6002 are anti human IgG mAbs with KD values of 30 and 340 nM, respectively. The limit of detection (LOD) for these mAbs was determined using ELISA, SPR, and ECL technologies and was generally correlated with the rank order of their affinities. The LODs for M1, M7, HP6030, and HP6002 by ELISA were 17 +/- 13, 26,000 +/- 9,020, 344,000 +/- 271,000, and 792,000 +/- 1,050,000 ng/ml, respectively. According to an industry-suggested detection limit of 500 ng/ml, the ELISA was not sensitive enough for detecting M7, HP6030, and HP6002, demonstrating its limitation for detection of low- affinity mAbs. The SPR method lowered the LOD for M7 to 3,900 ng/ml, which was above the industry requirement. The ECL method lowered the LOD for all antibodies tested. Importantly, the ECL method lowered the LOD for M7 to 570 +/- 370 ng/ml, which is close to the industry requirement. Since the ECL method had demonstrated a high serum tolerance, its detection capability may be improved by using a higher percentage of serum in the assay matrix. Although a hook effect was observed with ECL methods, the methods could still detect anti-drug antibody (ADA) concentrations greater than 1 mg/ml, which minimizes concerns that high-titer ADA responses could be missed. The results demonstrated the superiority of an ECL method in detecting high- and low- affinity antibodies when compared to the ELISA and SPR methods.

Research paper thumbnail of Age-specific malaria seroprevalence rates: a cross-sectional analysis of malaria transmission in the Ouest and Sud-Est departments of Haiti

Malaria Journal, 2014

Background: Malaria transmission continues to occur in Haiti, with 25,423 confirmed cases of Plas... more Background: Malaria transmission continues to occur in Haiti, with 25,423 confirmed cases of Plasmodium falciparum and 161,236 suspected infections reported in 2012. At low prevalence levels, passive surveillance measures, which rely primarily on reports from health systems, becomes less appropriate for capturing annual malaria incidence. To improve understanding of malaria transmission in Haiti, participants from the Ouest and Sud-Est departments were screened using a highly sensitive enzyme-linked immunosorbent assay (ELISA). Methods: Between February and May 2013, samples were collected from four different sites including a rural community, two schools, and a clinic located in the Ouest and Sud-Est departments of Haiti. A total of 815 serum samples were screened for malaria antibodies using an indirect ELISA coated with vaccine candidates apical membrane antigen (AMA-1) and merozoite surface protein-1 (MSP-1 19 ). The classification of previous exposure was established by using a threshold value that fell three standard deviations above the mean absorbance for suspected seronegative population members (OD of 0.32 and 0.26 for AMA-1 and MSP-1, respectively). The observed seroprevalence values were used to fit a modified reverse catalytic model to yield estimates of seroconversion rates. Results: Of the samples screened, 172 of 815 (21.1%) were AMA-1 positive, 179 of 759 (23.6%) were MSP-1 19 positive, and 247 of 815 (30.3%) were positive for either AMA-1 or MSP-1; indicating rates of previous infections between 21.1% and 30.3%. Not surprisingly, age was highly associated with the likelihood of previous infection (p-value <0.001). After stratification by age, the estimated seroconversion rate indicated that the annual malaria transmission in the Ouest and Sud-Est department is approximately 2.5% (95% CI SCR: 2.2%, 2.8%). Conclusions: These findings suggest that despite the absence of sustained malaria control efforts in Haiti, transmission has remained relatively low over multiple decades. Elimination in Haiti appears to be feasible; however, surveillance must continue to be strengthened in order to respond to areas with high transmission and measure the impact of future interventions.

Research paper thumbnail of Th17 Cells in Immunity and Autoimmunity

Clinical and Developmental Immunology, 2013

Th17 and IL-17 play important roles in the clearance of extracellular bacterial and fungal infect... more Th17 and IL-17 play important roles in the clearance of extracellular bacterial and fungal infections. However, strong evidence also implicates the Th17 lineage in several autoimmune disorders including multiple sclerosis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and asthma. The Th17 subset has also been connected with type I diabetes, although whether it plays a role in the pathogenicity of or protection from the disease remains a controversial issue. In this review we have provided a comprehensive overview of Th17 pathogenicity and function, including novel evidence for a protective role of Th17 cells in conjunction with the microbiota gut flora in T1D onset and progression.

Research paper thumbnail of Detection of High and Low-Affinity Antibodies Against a Human Monoclonal Antibody Using Various Technology Platforms

Assay and Drug Development Technologies, 2007

The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunoso... more The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and electrochemiluminescence (ECL) methods was evaluated using a panel of murine mAbs with affinities ranging from 0.057 to 340 nM. M1 and M7 are anti-idiotypic mAbs against a human mAb, ABX10, with dissociation equilibrium constant (KD) values of 0.057 and 7.2 nM, respectively. HP6030 and HP6002 are anti human IgG mAbs with KD values of 30 and 340 nM, respectively. The limit of detection (LOD) for these mAbs was determined using ELISA, SPR, and ECL technologies and was generally correlated with the rank order of their affinities. The LODs for M1, M7, HP6030, and HP6002 by ELISA were 17 +/- 13, 26,000 +/- 9,020, 344,000 +/- 271,000, and 792,000 +/- 1,050,000 ng/ml, respectively. According to an industry-suggested detection limit of 500 ng/ml, the ELISA was not sensitive enough for detecting M7, HP6030, and HP6002, demonstrating its limitation for detection of low- affinity mAbs. The SPR method lowered the LOD for M7 to 3,900 ng/ml, which was above the industry requirement. The ECL method lowered the LOD for all antibodies tested. Importantly, the ECL method lowered the LOD for M7 to 570 +/- 370 ng/ml, which is close to the industry requirement. Since the ECL method had demonstrated a high serum tolerance, its detection capability may be improved by using a higher percentage of serum in the assay matrix. Although a hook effect was observed with ECL methods, the methods could still detect anti-drug antibody (ADA) concentrations greater than 1 mg/ml, which minimizes concerns that high-titer ADA responses could be missed. The results demonstrated the superiority of an ECL method in detecting high- and low- affinity antibodies when compared to the ELISA and SPR methods.

Research paper thumbnail of Detection of High- and Low-Affinity Antibodies Against a Human Monoclonal Antibody Using Various Technology Platforms

ASSAY and Drug Development Technologies, 2007

The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunoso... more The effect of monoclonal antibody (mAb) affinity on the detection limit of enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and electrochemiluminescence (ECL) methods was evaluated using a panel of murine mAbs with affinities ranging from 0.057 to 340 nM. M1 and M7 are anti-idiotypic mAbs against a human mAb, ABX10, with dissociation equilibrium constant (KD) values of 0.057 and 7.2 nM, respectively. HP6030 and HP6002 are anti human IgG mAbs with KD values of 30 and 340 nM, respectively. The limit of detection (LOD) for these mAbs was determined using ELISA, SPR, and ECL technologies and was generally correlated with the rank order of their affinities. The LODs for M1, M7, HP6030, and HP6002 by ELISA were 17 +/- 13, 26,000 +/- 9,020, 344,000 +/- 271,000, and 792,000 +/- 1,050,000 ng/ml, respectively. According to an industry-suggested detection limit of 500 ng/ml, the ELISA was not sensitive enough for detecting M7, HP6030, and HP6002, demonstrating its limitation for detection of low- affinity mAbs. The SPR method lowered the LOD for M7 to 3,900 ng/ml, which was above the industry requirement. The ECL method lowered the LOD for all antibodies tested. Importantly, the ECL method lowered the LOD for M7 to 570 +/- 370 ng/ml, which is close to the industry requirement. Since the ECL method had demonstrated a high serum tolerance, its detection capability may be improved by using a higher percentage of serum in the assay matrix. Although a hook effect was observed with ECL methods, the methods could still detect anti-drug antibody (ADA) concentrations greater than 1 mg/ml, which minimizes concerns that high-titer ADA responses could be missed. The results demonstrated the superiority of an ECL method in detecting high- and low- affinity antibodies when compared to the ELISA and SPR methods.

Research paper thumbnail of Age-specific malaria seroprevalence rates: a cross-sectional analysis of malaria transmission in the Ouest and Sud-Est departments of Haiti

Malaria Journal, 2014

Background: Malaria transmission continues to occur in Haiti, with 25,423 confirmed cases of Plas... more Background: Malaria transmission continues to occur in Haiti, with 25,423 confirmed cases of Plasmodium falciparum and 161,236 suspected infections reported in 2012. At low prevalence levels, passive surveillance measures, which rely primarily on reports from health systems, becomes less appropriate for capturing annual malaria incidence. To improve understanding of malaria transmission in Haiti, participants from the Ouest and Sud-Est departments were screened using a highly sensitive enzyme-linked immunosorbent assay (ELISA). Methods: Between February and May 2013, samples were collected from four different sites including a rural community, two schools, and a clinic located in the Ouest and Sud-Est departments of Haiti. A total of 815 serum samples were screened for malaria antibodies using an indirect ELISA coated with vaccine candidates apical membrane antigen (AMA-1) and merozoite surface protein-1 (MSP-1 19 ). The classification of previous exposure was established by using a threshold value that fell three standard deviations above the mean absorbance for suspected seronegative population members (OD of 0.32 and 0.26 for AMA-1 and MSP-1, respectively). The observed seroprevalence values were used to fit a modified reverse catalytic model to yield estimates of seroconversion rates. Results: Of the samples screened, 172 of 815 (21.1%) were AMA-1 positive, 179 of 759 (23.6%) were MSP-1 19 positive, and 247 of 815 (30.3%) were positive for either AMA-1 or MSP-1; indicating rates of previous infections between 21.1% and 30.3%. Not surprisingly, age was highly associated with the likelihood of previous infection (p-value <0.001). After stratification by age, the estimated seroconversion rate indicated that the annual malaria transmission in the Ouest and Sud-Est department is approximately 2.5% (95% CI SCR: 2.2%, 2.8%). Conclusions: These findings suggest that despite the absence of sustained malaria control efforts in Haiti, transmission has remained relatively low over multiple decades. Elimination in Haiti appears to be feasible; however, surveillance must continue to be strengthened in order to respond to areas with high transmission and measure the impact of future interventions.

Research paper thumbnail of Th17 Cells in Immunity and Autoimmunity

Clinical and Developmental Immunology, 2013

Th17 and IL-17 play important roles in the clearance of extracellular bacterial and fungal infect... more Th17 and IL-17 play important roles in the clearance of extracellular bacterial and fungal infections. However, strong evidence also implicates the Th17 lineage in several autoimmune disorders including multiple sclerosis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and asthma. The Th17 subset has also been connected with type I diabetes, although whether it plays a role in the pathogenicity of or protection from the disease remains a controversial issue. In this review we have provided a comprehensive overview of Th17 pathogenicity and function, including novel evidence for a protective role of Th17 cells in conjunction with the microbiota gut flora in T1D onset and progression.