A smartphone dongle for diagnosis of infectious diseases at the point of care.

This work demonstrates that a full laboratory-quality immunoassay can be run on a smartphone accessory. This low-cost dongle replicates all mechanical, optical, and electronic functions of a laboratory-based enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy; all necessary power is drawn from a smartphone. Rwandan health care workers used the dongle to test whole blood obtained via fingerprick from 96 patients enrolling into care at prevention of mother-to-child transmission clinics or voluntary counseling and testing centers. The dongle performed a triplexed immunoassay not currently available in a single test format: HIV antibody, treponemal-specific antibody for syphilis, and nontreponemal antibody for active syphilis infection. In a blinded experiment, health care workers obtained diagnostic results in 15 min from our triplex test that rivaled the gold standard of laboratory-based HIV ELISA and rapid plasma reagin (a screening test for syphilis), with sensitivity of 92 to 100% and specificity of 79 to 100%, consistent with needs of current clinical algorithms. Patient preference for the dongle was 97% compared to laboratory-based tests, with most pointing to the convenience of obtaining quick results with a single fingerprick. This work suggests that coupling microfluidics with recent advances in consumer electronics can make certain laboratory-based diagnostics accessible to almost any population with access to smartphones.

Cleavage/alteration of interleukin-8 by matrix metalloproteinase-9 in the female lower genital tract.

OBJECTIVE: Interleukin-8 (IL-8, CXCL8) plays important roles in immune responses at mucosal sites including in the lower genital tract. Since several types of bacteria produce proteases that cleave IL-8 and many types of bacteria can be present in lower genital tract microbiota, we assessed genital fluids for IL-8 cleavage/alteration. STUDY DESIGN: Genital fluids collected by lavage from 200 women (23 HIV-seronegative and 177 HIV-seropositive) were tested for IL-8 cleavage/alteration by ELISA. RESULTS: IL-8 cleaving/altering activity was observed in fluids from both HIV-positive (28%) and HIV-negative women (35%). There was no clear relationship between the activity and the types of bacteria present in the lower genital tract as determined by high-throughput sequencing of the 16S rRNA gene. Protease inhibitors specific for matrix metalloproteinases (MMPs) reduced the activity and a multiplex assay that detects both inactive and active MMPs showed the presence of multiple MMPs, including MMP-1, -3, -7, -8, -9, -10 and -12 in genital secretions from many of the women. The IL-8-cleaving/altering activity significantly correlated with active MMP-9 as well as with cleavage of a substrate that is acted on by several active MMPs. CONCLUSIONS: These studies show that multiple MMPs are present in the genital tract of women and strongly suggest that MMP-9 in genital secretions can cleave IL-8 at this mucosal site. These studies suggest that MMP-mediated cleavage of IL-8 can modulate inflammatory responses in the lower genital tract.

Comparison of lower genital tract microbiota in HIV-infected and uninfected women from Rwanda and the US.

INTRODUCTION: Previous studies have shown that alterations of the bacterial microbiota in the lower female genital tract influence susceptibility to HIV infection and shedding. We assessed geographic differences in types of genital microbiota between HIV-infected and uninfected women from Rwanda and the United States. METHODS: Genera of lower genital tract bacterial microbiota were identified by high-throughput pyrosequencing of the 16S rRNA gene from 46 US women (36 HIV-infected, 10 HIV-uninfected) and 40 Rwandan women (18 HIV-infected, 22 HIV-uninfected) with similar proportions of low (0-3) Nugent scores. Species of Lactobacillus were identified by assembling sequences along with reference sequences into phylogenetic trees. Prevalence of genera and Lactobacillus species were compared using Fisher's exact tests. RESULTS: Overall the seven most prevalent genera were Lactobacillus (74%), Prevotella (56%), Gardnerella (55%), Atopobium (42%), Sneathia (37%), Megasphaera (30%), and Parvimonas (26%), observed at similar prevalences comparing Rwandan to US women, except for Megasphaera (20% vs. 39%, p = 0.06). Additionally, Rwandan women had higher frequencies of Mycoplasma (23% vs. 7%, p = 0.06) and Eggerthella (13% vs. 0%, p = 0.02), and lower frequencies of Lachnobacterium (8% vs. 35%, p<0.01) and Allisonella (5% vs. 30%, p<0.01), compared with US women. The prevalence of Mycoplasma was highest (p<0.05) in HIV-infected Rwandan women (39%), compared to HIV-infected US women (6%), HIV-uninfected Rwandan (9%) and US (10%) women. The most prevalent lactobacillus species in both Rwandan and US women was L. iners (58% vs. 76%, p = 0.11), followed by L. crispatus (28% vs. 30%, p = 0.82), L. jensenii (20% vs. 24%, p = 0.80), L. gasseri (20% vs. 11%, p = 0.37) and L. vaginalis (20% vs. 7%, p = 0.10). DISCUSSION: We found similar prevalence of most major bacterial genera and Lactobacillus species in Rwandan and US women. Further work will be needed to establish whether observed differences differentially impact lower genital tract health or susceptibility to genital infections.

Assessment of haematological parameters in HIV-infected and uninfected Rwandan women: a cross-sectional study.

OBJECTIVES: Although haematological abnormalities are common manifestations of HIV infection, few studies on haematological parameters in HIV-infected persons have been undertaken in sub-Saharan Africa. The authors assessed factors associated with haematological parameters in HIV-infected antiretroviral-naïve and HIV-uninfected Rwandan women. STUDY DESIGN: Cross-sectional analysis of a longitudinal cohort. SETTING: Community-based women's associations. PARTICIPANTS: 710 HIV-infected (HIV+) antiretroviral-naïve and 226 HIV-uninfected (HIV-) women from the Rwanda Women's Interassociation Study Assessment. Haematological parameters categorised as (abnormal vs normal) were compared by HIV status and among HIV+ women by CD4 count category using proportions. Multivariate logistic regression models using forward selection were fit. RESULTS: Prevalence of anaemia (haemoglobin (Hb) <12.0 g/dl) was higher in the HIV+ group (20.5% vs 6.3%; p<0.001), and increased with lower CD4 counts: ≥350 (7.6%), 200-349 (16%) and <200 cells/mm(3) (32.2%). Marked anaemia (Hb <10.0 g/dl) was found in 4.2% of HIV+ and none of the HIV- women (p<0.001), and was highest in HIV+ women with CD4 <200 cells/mm(3) (8.4%). The HIV+ were more likely than HIV- women (4.2 vs 0.5%, respectively, p=0.002) to have moderate neutropenia with white blood cells <2.0×10(3) cells/mm(3) and 8.4% of HIV+ women with CD4 <200 cells/mm(3) had moderate neutropenia. In multivariate logistic regression analysis, BMI (OR 0.87/kg/m(2), 95% CI 0.82 to 0.93; p<0.001), CD4 200-350 vs HIV- (OR 3.59, 95% CI 1.89 to 6.83; p<0.001) and CD4 <200 cells/mm(3) vs HIV- (OR 8.09, 95% CI 4.37 to 14.97; <0.001) had large independent associations with anaemia. There were large independent associations of CD4 <200 cells/mm(3) vs HIV- (OR 7.18, 95% CI 0.78 to 65.82; p=0.081) and co-trimoxazole and/or dapsone use (OR 5.69, 95% CI 0.63 to 51.45; p=0.122) with moderate neutropenia. CONCLUSIONS: Anaemia was more common than neutropenia or thrombocytopenia in the HIV-infected Rwandan women. Future comparisons of haematological parameters in HIV-infected patients before and after antiretroviral therapy initiation are warranted.

Selection of T-cell receptors with a recurrent CDR3ß peptide-contact motif within the repertoire of alloreactive CD8(+) T cells.

Peptide/MHC complexes recognized by alloreactive T lymphocytes (TLs) have been identified, but their contribution to in vivo allo-rejection is not known. We previously characterized the peptide pBM1, highly represented among endogenous H-2K(b) (K(b) )-associated peptides and critically required to induce full activation of H-2(k) monoclonal CD8(+) TLs expressing the cognate TCR-BM3.3. Here, we asked whether a pBM1/K(b) -specific TL subset could be detected within a polyclonal TL population rejecting allogeneic cells in vivo. We show that the proportion of pBM1/K(b) -binding CD8(+) TLs increased from <0.04% in naïve mice to 3% of activated CD44(+) CD8(+) TLs in H-2(k) mice rejecting K(b) -expressing cells. Among these, TCR-Vß2 usage was greatly enriched, and 75% of them shared a TCR-Vß2 CDR3ß motif with the prototype TCR-BM3.3. Fewer than 5% of K(b) -reactive CD44(+) CD8(+) TLs not binding pBM1/K(b) displayed this CDR3ß motif. We found that the recurrent CDR3ß motif of pBM1/K(b) -binding TLs was assembled from distinct V/D/J recombination events, suggesting that it is recruited upon immunization for its optimal TCR-peptide/MHC fit. Thus, a CDR3ß motif generated by a process akin to "convergent recombination" accounts for a sizable fraction of the alloreactive anti-K(b) TCR repertoire.