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Objectives The aim of the study was to describe patient characteristics and outcomes among HIV-positive adults presenting to a Zambian tertiary care hospital with new-onset seizures. Methods From July 2011 to June 2013, adults with seizures and a known or probable diagnosis of HIV infection were screened for a cohort study. Demographic and clinical data were obtained, including information on engagement in HIV services and in-patient mortality. Analyses were conducted to identify characteristics associated with poor engagement in care and death. Results A total of 320 of 351 screened adults were HIV-positive, with 268 of 320 experiencing new-onset seizures. Of these, 114 of 268 (42.5%) were female, and their mean age was 36.8 years. Seventy-nine of the 268 patients (29.5%) were diagnosed with HIV infection during the index illness. Among those who were aware of their HIV-positive status, 59 of 156 (37.8%) had disengaged from care. Significant functional impairment ( Karnofsky score < 50) was evident in 44.0% of patients. Cerebrospinal fluid was not obtained in 108 of 268 (40.3%). In-patient mortality outcomes were available for 214 patients, and 47 of these 214 (22.0%) died during hospitalization. Patients with significant functional impairment were more likely to undergo lumbar puncture ( P = 0.046). Women and the functionally impaired were more likely to die ( P = 0.04 and < 0.001, respectively). Conclusions Despite the availability of care, less than half of HIV-infected people with new-onset seizures were actively engaged in care and in-patient mortality rates were high. In the absence of clinical contraindication, lumbar puncture should be performed to diagnose treatable conditions and reduce morbidity and mortality. Continued efforts are needed to expand community-based testing and improve HIV care retention rates. Qualitative studies are needed to elucidate factors contributing to lumbar puncture usage in this population. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflict of Interest for ALL Authors: NONE DECLARED

Objective: To determine the long-term outcomes, including mortality and recurrent seizures, among children living with HIV (CLWH) who present with new onset seizure., Methods: Zambian CLWH and new onset seizure were enrolled prospectively to determine the risk of and risk factors for recurrent seizures. Demographic data, clinical profiles, index seizure etiology, and 30-day mortality outcomes were previously reported. After discharge, children were followed quarterly to identify recurrent seizures and death. Given the high risk of early death, risk factors for recurrent seizure were evaluated using a model that adjusted for mortality., Results: Among 73 children enrolled, 28 died (38%), 22 within 30-days of the index seizure. Median follow-up was 533 days (IQR 18-957) with 5% (4/73) lost to follow-up. Seizure recurrence was 19% among the entire cohort. Among children surviving at least 30-days after the index seizure, 27% had a recurrent seizure. Median time from index seizure to recurrent seizure was 161 days (IQR 86-269). Central nervous system opportunistic infection (CNS OI), as the cause for the index seizure was protective against recurrent seizures and higher functional status was a risk factor for seizure recurrence., Significance: Among CLWH presenting with new onset seizure, mortality risks remain elevated beyond the acute illness period. Recurrent seizures are common and are more likely in children with higher level of functioning even after adjusting for the outcome of death. Newer antiseizure medications appropriate for co-usage with antiretroviral therapies are needed for the care of these children. CNS OI may represent a potentially reversible provocation for the index seizure, while seizures in high functioning CLWH without a CNS OI may be the result of a prior brain injury or susceptibility to seizures unrelated to HIV and thus represent an ongoing predisposition to seizures., Plain Language Summary: This study followed CLWH who experienced a new onset seizure to find out how many go on to have more seizures and identify any patient characteristics associated with having more seizures. The study found that mortality rates continue to be high beyond the acute clinical presentation with new onset seizure. Children with a CNS OI causing the new onset seizure had a lower risk of later seizures, possibly because the trigger for the seizure can be treated. In contrast, high functioning children without a CNS OI were at higher risk of future seizures., (© 2024 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Background: Seizures are relatively common among children with HIV in low- and middle-income countries and are associated with significant morbidity and mortality. Early treatment with antiretroviral therapy (ART) may reduce this risk by decreasing rates of central nervous system infections and HIV encephalopathy., Methods: We conducted a prospective, unmatched case-control study. We enrolled children with new-onset seizure from University Teaching Hospital in Lusaka, Zambia and 2 regional hospitals in rural Zambia. Controls were children with HIV and no history of seizures. Recruitment took place from 2016 to 2019. Early treatment was defined as initiation of ART before 12 months of age, at a CD4 percentage >15% in children aged 12-60 months or a CD4 count >350 cells/mm 3 for children aged 60 months or older. Logistic regression models were used to evaluate the association between potential risk factors and seizures., Results: We identified 73 children with new-onset seizure and compared them with 254 control children with HIV but no seizures. Early treatment with ART was associated with a significant reduction in the odds of seizures [odds ratio (OR) 0.04, 95% confidence interval: 0.02 to 0.09; P < 0.001]. Having an undetectable viral load at the time of enrollment was strongly protective against seizures (OR 0.03, P < 0.001), whereas history of World Health Organization Stage 4 disease (OR 2.2, P = 0.05) or CD4 count <200 cells/mm 3 (OR 3.6, P < 0.001) increased risk of seizures., Conclusions: Early initiation of ART and successful viral suppression would likely reduce much of the excess seizure burden in children with HIV., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Competing Interests: Conflict-of-Interest Disclosures: None to disclose.

Background: HIV incidence has recently increased among people who inject drugs (PWID) across the United States, with outbreaks occurring in states with long-standing syringe service programs (SSPs) including Massachusetts (MA). Antiretroviral pre-exposure prophylaxis (PrEP) is an evidence-based HIV prevention strategy recommended for PWID, but uptake in this marginalized population is extraordinarily low., Methods: We describe the design and procedures for a National Institute on Drug Abuse (NIDA)-funded (R01) randomized controlled trial (RCT) testing the efficacy of "PrEP for Health," a multicomponent behavioral intervention to increase PrEP uptake, adherence, and persistence among HIV-negative PWID attending SSPs in two areas of the U.S. Northeast that are heavily affected by injection-related HIV transmission. Participants are equally randomized to receive the "PrEP for Health" intervention (involving individually tailored HIV and PrEP education, motivational interviewing, problem-solving skills and planning, and ongoing navigation support) or an enhanced standard of care (eSOC) control condition involving a brief educational video on the utility of PrEP for HIV prevention. Co-primary outcomes are PrEP uptake (using medical/pharmacy records) and adherence (using tenofovir quantification in hair samples); a secondary outcome is PrEP persistence (using medical/pharmacy records) over 12 months. Major assessments occur at baseline, 1-, 3-, 6-, and 12-month follow-up visits. Planned analyses will examine intervention efficacy, specific hypothesized conceptual mediators of the intervention effect (e.g., self-perceived HIV risk; PrEP knowledge, interest in use, motivation, and behavioral skills) and epidemiologically linked moderators (e.g., age; gender; condomless vaginal or anal sex)., Discussion: Findings from our extensive preliminary research with the study population revealed that a multicomponent, theory-based intervention targeting PrEP knowledge, motivation, self-efficacy, behavioral skills, and structural barriers to PrEP access is urgently needed for PWID who are at risk of HIV acquisition. We also learned that SSPs represent a highly acceptable service setting for delivering such interventions. In this study, we are evaluating the efficacy of the "PrEP for Health" intervention. If efficacious, findings from our implementation evaluation could help guide its dissemination to diverse SSPs and possibly other community-based settings accessed by this population., Trial Registration: ClinicalTrials.gov number NCT04430257, registered June 12, 2020., (© 2023. The Author(s).)

Objective: This study describes clinical profiles including human immunodeficiency virus (HIV) disease history and seizure etiology among children living with HIV presenting with new-onset seizure during the era of antiretroviral therapy (ART) in Zambia. 30-day mortality and cause of death are also reported., Methods: Children living with HIV (CLWHIV) with new-onset seizures were prospectively evaluated at one large urban teaching hospital and two non-urban healthcare facilities. Interviews with family members, review of medical records, and where needed, verbal autopsies were undertaken. Two clinicians who were not responsible for the patients' care independently reviewed all records and assigned seizure etiology and cause of death with adjudication as needed., Results: From April 2016 to June 2019, 73 children (49 urban, 24 rural) were identified. Median age was 6 years (IQR 2.2-10.0) and 39 (53%) were male children. Seizures were focal in 36 (49%) and were often severe, with 37% presenting with multiple recurrent seizures in the 24 hours before admission or in status epilepticus. Although 36 (49%) were on ART at enrollment, only 7 of 36 (19%) were virally suppressed. Seizure etiologies were infectious in over half (54%), with HIV encephalitis, bacterial meningitis, and tuberculous meningitis being the most common. Metabolic causes (19%) included renal failure and hypoglycemia. Structural lesions identified on imaging accounted for 10% of etiologies and included stroke and non-accidental trauma. No etiology could be identified in 12 (16%) children, most of whom died before the completion of clinical investigations. Twenty-two (30%) children died within 30 days of the index seizure., Significance: Despite widespread ART roll out in Zambia, new-onset seizure in CLWHIV occurs in the setting of advanced, active HIV disease. Seizure severity/burden is high as is early mortality. Enhanced programs to assure early ART initiation, improve adherence, and address ART failure are needed to reduce the burden of neurological injury and premature death in CLWHIV., (© 2022 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: Interactions between enzyme-inducing anti-seizure medications (EI-ASMs) and antiretroviral drugs (ARVs) can lead to decreased ARV levels and may increase the likelihood of viral resistance. We conducted a study to determine if co-usage of ARVs and EI-ASMs is associated with ARV-resistant human immunodeficiency virus (HIV) among people living with HIV in Zambia., Methods: Eligible participants were ≥18 years of age and concurrently taking ASMs and ARVs for at least 1 month of the prior 6-month period. Data were obtained regarding medication and HIV history. CD4 counts, plasma viral loads (pVLs), and HIV genotype and resistance profile in participants with a pVL >1000 copies/mL were obtained. Pearson's test of independence was used to determine whether treatment with EI-ASM was associated with pVL >1000/mL copies., Results: Of 50 participants, 41 (82%) were taking carbamazepine (37 on monotherapy), and all had stable regimens in the prior 6 months. Among the 13 ARV regimens used, 68% had a tenofovir/lamivudine backbone. The majority (94%) were on a stable ARV regimen for >6 months. Median CD4 nadir was 205 cells/mm 3 (interquartile range [IQR] 88-389), and 60% of participants had commenced ARV treatment before advanced disease occurred. Mean CD4 count at enrollment was 464 cells/mm 3 (SD 226.3). Seven participants (14%) had a CD4 count <200 cells/mm 3 . Four (8%) had a pVL >1000 copies/mL; all were on carbamazepine. Three participants with elevated pVL had a CD4 count <200 cells/mm 3 . None had documented adherence concerns by providers; however, two had events concerning for clinical failure. HIV genotype testing showed mutations in three participants. Carbamazepine was not found to correlate with elevated pVL (P = .58)., Significance: EI-ASMs are commonly used in sub-Saharan Africa. Despite concurrent use of EI-ASMs and ARVs, the majority of participants showed CD4 counts >200 cells/mm 3 and were virally suppressed. Carbamazepine was not associated with an increased risk of virological failure or ARV-resistant HIV., (© 2020 International League Against Epilepsy.)

The ongoing syndemic of substance use disorder and human immunodeficiency virus infection threatens progress made in preventing new infections and improving outcomes among those infected. To address this challenge effectively, human immunodeficiency virus physicians must take an increased role in the screening, diagnosis, and treatment of substance use disorders. Such treatment decreases human immunodeficiency virus risk behaviors and improves human immunodeficiency virus and substance use disorder-related outcomes. An effective response to this syndemic requires increased access to adjuvant interventions and a radical movement away from the current stigmatization and criminalization of those suffering from substance use disorders., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Recurrent seizure risks in HIV-positive people with new-onset seizure are largely unknown, making it challenging to offer optimal recommendations regarding antiepileptic drug (AED) initiation. Existing outcomes data is limited, and risk factor identification requires a diagnostic assessment, which is often unavailable in regions heavily effected by HIV, like sub-Saharan Africa., Methods: HIV-positive Zambian adults with new-onset seizure were enrolled in a prospective cohort study to determine seizure recurrence and risk factors for recurrence. Seizure etiology was evaluated, and recurrent seizures and medication usage were assessed during clinic visits. Due to unexpectedly high mortality rates, predictors of death were evaluated using proportional hazards with Gray's test to compare cumulative incidence functions for recurrent seizure across groups adjusting for the competing outcome of death., Results: 95 patients were enrolled (mean age 37 years, 43% female, 83% with Karnofsky > 50) and followed for a mean of 293 days (median 241 (IQR: 29-532)). At presentation, 50 (53%) were in status epilepticus. The majority (91, 85%) had advanced HIV disease and 65 (68%) were not on combined antiretroviral therapy (cART). After extensive workup, seizure etiology remained unknown in 16 (17%). Average time to cART initiation after enrollment was 61 days. During follow up, 37 (39%) died and 23 (24%) had recurrent seizure. Most deaths (25/37, 68%) occurred in the first 60 days post-index seizure. Individuals with advanced HIV were more likely to die (HR: 19.1 [95% CI: 1.1-333.4]) as were those whose seizure etiology remained unknown (HR: 2.2 [95% CI: 1.1-4.4]). Among participants that survived from enrolment to the end of data collection on 10 May 2013 (n = 58), 20 (34%) experienced recurrent seizures., Conclusions: New-onset seizure among HIV-positive Zambian adults is associated with high mortality despite good functional status prior to presentation. Advanced HIV infection and failure to identify an underlying seizure etiology are associated with greater mortality. Recurrent seizures occur in over a third of survivors within only 2 years of follow-up. This provides evidence to support AED initiation after first seizure in HIV-positive individuals with advanced HIV disease at the time of presentation though the risks of AED-cART interactions remain a concern and warrant further study.

AbstractConcurrent treatment with combination antiretroviral therapy (cART) and an enzyme-inducing antiepileptic drug (EI-AED) is common in resource-limited settings; however, the incidence and impact of adverse effects in cotreated patients is largely unknown. Symptoms of adverse effects were assessed by both spontaneous report and checklist for 145 human immunodeficiency virus (HIV)-infected Zambian adults initiating various treatment combinations, such as cART with an EI-AED ( N = 20), cART only ( N = 43), or neither drug (untreated; N = 82). At study baseline, the cART + EI-AED group reported more headache, generalized fatigue, problems with concentration, and depression than the untreated group ( P < 0.01 for all). At 2 weeks, a greater proportion of cART + EI-AED participants reported increased nausea or vomiting compared with baseline ( P < 0.05). Adverse effects did not appear to impact self-reported adherence at 2 weeks as 100% cART adherence was reported in 19 of 20 (95%) and 42 of 43 (98%) cART + EI-AED and cART-only participants, respectively; 100% EI-AED adherence was reported in 19 of 20 (95%) participants. However, adherence at 6 months was suboptimal in both groups with 18 of 33 (56%) participants on cART experiencing greater than 1-week lapse in pharmacy-reported medication supply. Our results highlight the need to educate patients about the increased potential for nausea and vomiting with cART + EI-AED cotreatment. Although adherence was high early during treatment, adherence should be reinforced overtime to minimize the potential for HIV and/or epilepsy treatment failure.

AbstractZambia and other sub-Saharan nations suffer from a critical shortage of trained health-care professionals to combat the human immunodeficiency virus/acquired immunodeficiency syndrome crisis. The University of Maryland and the Zambian Ministry of Health have partnered over the past decade to develop health-care capacity among physicians, nurses, and community health workers. We describe novel interventions to train health-care workers at all levels and argue that our collaboration represents a successful model for such partnerships between western medical institutions and African governmental health agencies.

Objective: To identify the etiology of new-onset seizure in HIV-infected Zambian adults and identify risk factors for seizure recurrence., Methods: A prospective cohort study enrolling HIV-infected adults with new-onset seizure within 2 weeks of index seizure obtained clinical, laboratory, and neuroimaging data to determine seizure etiology. Participants were followed to identify risk factors for seizure recurrence. Risk factors for mortality were examined as mortality rates were unexpectedly high., Results: Eighty-one patients with CSF for analysis were enrolled and followed for a median of 306 days (interquartile range 61-636). Most (91%) were at WHO stage III/IV and 66 (81%) had a pre-seizure Karnofsky score ≥50. Prolonged or multiple seizures occurred in 46 (57%), including 12 (15%) with status epilepticus. Seizure etiologies included CNS opportunistic infections (OI) in 21 (26%), hyponatremia in 23 (28%), and other infections in 8 (10%). OIs included Cryptococcus (17%), JC virus (7%) and 5% each for tuberculosis, cytomegalovirus, and varicella-zoster virus. No etiology could be identified in 16 (20%). Thirty (37%) patients died during follow-up and 20 (25%) had recurrent seizures with survival being the only identifiable risk factor., Conclusions: HIV-infected adults with new-onset seizure in Zambia often have advanced HIV disease with OI being the most frequent seizure etiology. Seizure recurrence is common but no risk factors for recurrence other than survival were identified. These findings suggest an urgent need for immune reconstitution in this population. Initiating treatment for seizure prophylaxis where only enzyme-inducing antiepileptic medications are available could threaten antiretroviral efficacy., (© 2016 American Academy of Neurology.)

Objective: To describe acute EEG findings in HIV-infected adults with new-onset seizure, assess baseline clinical characteristics associated with EEG abnormalities, and evaluate the relationship between EEG abnormalities and recurrent seizure., Methods: Eighty-one HIV-infected adults with new-onset seizure had EEG recordings during their index admission. Baseline characteristics assessed included HIV stage, seizure semiology, serum and CSF studies, neuroimaging, cognitive function based on the Zambian Mini-Mental State Examination and International HIV Dementia Scale, and psychiatric symptoms using the Shona Symptom Questionnaire. We evaluated the relationship between baseline characteristics and EEG abnormalities. Patients were followed for seizure recurrence, and the association between acute EEG abnormalities and seizure recurrence was assessed. Death was a secondary outcome., Results: Fifty-five patients had abnormal EEGs (68%): 18 (22%) had interictal spikes (12) or a recorded seizure (6). Among baseline clinical characteristics, more advanced HIV disease (p = 0.039) and any imaging abnormality (p = 0.027) were associated with abnormal EEGs. Cortical (p = 0.008) and white matter (p = 0.004) abnormalities were associated with slow posterior dominant rhythm. Patients were followed for a median of 303 days (interquartile range 103-560). Twenty-four (30%) died and 23 (28%) had recurrent seizures. EEG abnormalities were not associated with recurrent seizure. There was a nonsignificant association between seizures recorded during EEG and death (67% vs 26%, p = 0.051)., Conclusions: EEG abnormalities are common in this population, particularly in patients with imaging abnormalities and advanced HIV. Acute EEG abnormalities were not associated with recurrent seizure, but high mortality rates during follow-up limited this analysis., (© 2015 American Academy of Neurology.)

A prospective cohort study of new-onset seizure in people with human immunodeficiency virus (HIV) in Zambia is ongoing to determine the incidence of subsequent epilepsy and risk factors for epileptogenesis in this population. At enrollment, we evaluated this cohort for cognitive impairment and psychiatric morbidity. Over 50% of participants had cognitive impairment and significant psychiatric morbidity. Most participants had advanced HIV disease based on CD4+ T-cell count and World Health Organization stage, but we found no association between cognitive impairment or psychiatric morbidity and HIV disease staging., (© The American Society of Tropical Medicine and Hygiene.)

In HIV-positive individuals with first seizure, we describe neuroimaging findings, detail clinical and demographic risk factors for imaging abnormalities, and evaluate the relationship between imaging abnormalities and seizure recurrence to determine if imaging abnormalities predict recurrent seizures. Among 43 participants (mean 37.4 years, 56% were male), 16 (37%) were on antiretroviral drugs, 32 (79%) had advanced HIV disease, and (28) 66% had multiple seizures and/or status epilepticus at enrollment. Among those with cerebrospinal fluid studies, 14/31 (44%) had opportunistic infections (OIs). During follow-up, 9 (21%) died and 15 (35%) experienced recurrent seizures. Edema was associated with OIs (odds ratio: 8.79; confidence interval: 1.03-236) and subcortical atrophy with poorer scores on the International HIV Dementia Scale) (5.2 vs. 9.3; P=0.002). Imaging abnormalities were not associated with seizure recurrence or death (P>0.05). Seizure recurrence occurred in at least a third and over 20% died during follow-up. Imaging was not predictive of recurrent seizure or death, but imaging abnormalities may offer additional diagnostic insights in terms of OI risk and cognitive impairment.

In July 2010, the World Health Organization (WHO) released new guidelines entitled, "Antiretroviral Drugs for Treating Pregnant Women and Preventing HIV Infection in Infants: Towards universal access." Previewed in November 2009 in abridged form, the completed document highlights the key WHO recommendations for antiretroviral treatment (ART) and prophylaxis in pregnant women, and contains substantial changes from the 2006 guidelines. Of note, the new guidelines recommend ART for all pregnant women with a CD4 cell count (CD4) less than 350 cells/mm(3), regardless of their clinical stage; includes tenofovir (TDF) as an acceptable alternative component of an ART regimen in pregnant and breastfeeding women; encourages initiation of both ART and antiretroviral (ARV) prophylaxis early in pregnancy; eliminates single-dose nevirapine (sdNVP) per se as a prophylaxis option; lists three-drug ARV prophylaxis as an option for women who do not need ART for their own health; and introduces extended daily infant nevirapine (ED-NVP) as a strategy for prevention of breast milk transmission of HIV. This article reviews these new recommendations and their rationale, and highlights key implications and challenges to their implementation in the Zambian context.

Liddle's syndrome (pseudoaldosteronism) is an autosomal dominant form of human hypertension characterized by a constellation of findings suggesting constitutive activation of the amiloride-sensitive distal renal epithelial sodium channel. We demonstrate complete linkage of the gene encoding the beta subunit of the epithelial sodium channel to Liddle's syndrome in Liddle's original kindred. Analysis of this gene reveals a premature stop codon that truncates the cytoplasmic carboxyl terminus of the encoded protein in affected subjects. Analysis of subjects with Liddle's syndrome from four additional kindreds demonstrates either premature termination or frameshift mutations in this same carboxy-terminal domain in all four. These findings demonstrate that Liddle's syndrome is caused by mutations in the beta subunit of the epithelial sodium channel and have implications for the regulation of this epithelial ion channel as well as blood pressure homeostasis.

Homologies based on structural motifs characterize conserved structures and mechanisms of maintaining function. An algorithm was developed to quantitate homology among segments of two proteins based upon structural characteristics of an amphipathic alpha-helix. This helical mimicry algorithm scored homology among sequences of two proteins in terms of: (i) presence of Leu, Ile, Val, Phe, or Met in a longitudinal, hydrophobic strip-of-helix at positions n, n + 4, n + 7, n + 11, etc. in the primary sequence, (ii) identity or chemical similarity of amino acids at intervening positions and (iii) exchanges of amino acids from positions n to n - 1, n + 3, n + 4, n + 1, n - 3, n - 4 around n (on the surface of a putative helix). While such exchanges of amino acids on the surfaces of homologous helices may conserve function, they did not maintain specific interactions of those residues with apposing groups.

An alpha-helix terminates when the virtual extension of its most hydrophobic, longitudinal strip containing Leu, Ile, Val, Phe, and Met lacks those residues. In each of 247 helices a template was fitted to maximize the mean hydrophobicity of positions forming a longitudinal strip-of-helix. The template was then extended into sequences beyond the ends of the helices. Leu, Ile, Val, Phe, and Met occurred in positions in the longitudinal strip-of-helix at an increased frequency (p less than 0.001), but in the first and second positions beyond either end of each true helix, they occurred at the same frequency as for their empirical distribution over all the proteins. Excesses of Asp and Glu were found in the N-terminal loop, and of Arg, His, and Lys in specific positions about the C terminus of helices. The longitudinal hydrophobic strip, the smallest amino acid in that strip, and charged amino acids in that strip, related to rotational and longitudinal orientation of alpha-helices in 15 proteins. Adjacent helices generally crossed through their longitudinal hydrophobic strips. They usually crossed through the smallest residue in the strip. Charged residues, when they occurred in the strips, were excluded from the crossing regions.

We seek to identify consensus sequences in digested fragments of antigenic proteins regulating selection and major histocompatibility complex (MHC)-restricted presentation to T cells of epitopes within those fragments. One such pattern, of recurrent, hydrophobic sidechains forming a longitudinal hydrophobic strip when a sequence is coiled as an alpha-helix, is found in or near most T cell-presented epitopes. Such recurrent hydrophobicity may lead to protease-protected coiling of the fragment against endosomal membranes and transfer to MHC molecules. This concept leads to better identification of T cell-presented sequences and possible to engineering of T cell-presented vaccines to affect their potency and MHC restriction.