Correlation of the ratio of CD4+/CD8+ cells in lymph node fine needle aspiration biopsies with HIV clinical status. A preliminary study

Frequencies of lymphoid T-follicular helper cells obtained longitudinally by lymph node fine-needle aspiration correlate significantly with viral load in SIV-infected rhesus monkeys

BACKGROUND

T-follicular helper (T(FH)) cells are an important population in lymph nodes (LNs) contributing to the generation of highly specific B cells. For SIV studies in rhesus macaques (RM), analysis of LN is necessary, but restricted due to invasive sampling. We applied the minimally invasive LN fine-needle aspiration (LN-FNA) and examined dynamics of T(FH) cells during SIV infection.

MATERIALS AND METHODS

LN-FNA and LN resection were carried out on uninfected RM. Lymphocytes were analyzed by flow cytometry. Additionally, cells obtained by LN-FNA over time from SIV-infected RM were analyzed.

RESULTS

Percentages of lymphocyte subsets were similar in LN aspirates and whole LNs. Analysis of LN aspirates from SIV-infected RM demonstrated a decrease of CD4(+) T cells, while T(FH) cell frequencies increased over time and correlated significantly with plasma viral load.

CONCLUSIONS

By applying LN-FNA, we showed that T(FH) cell expansion in chronic SIV infection is associated with viral load.

Oral lichen planus and chronic junctional stomatitis: differences in lymphocyte subpopulations

OBJECTIVE

Oral lichen planus (OLP) is an oral counterpart or oral manifestation of the common skin disease lichen planus. Chronic junctional stomatitis (CJS) is a relatively unknown condition characterized by a stromal lymphocyte infiltrate, which is also a diagnostic feature of OLP. The differential diagnosis of OLP and CJS is unclear and they have been suggested to represent variants of the same disease.

MATERIAL AND METHODS

To investigate possible differences in lymphocyte (sub)populations between these two conditions, we immunostained 10 OLP and 10 CJS specimens for CD1-a, and the lymphocyte markers, CD3, CD4, CD5, CD8, and CD20. We scored the staining results by a four-step grading system and used the Fisher exact test to analyze them statistically.

RESULTS

The proportional amount of (CD20 positive) B lymphocytes was higher in CJS than in OLP and the predominance of CD4 positive T lymphocytes over CD8 positive T lymphocytes was stronger in OLP than in CJS. The differences were statistically significant.

CONCLUSION

The results reflect differences in the lymphatic infiltrate between OLP and CJS. Their significance needs further investigation.

FINE NEEDLE ASPIRATION CYTOLOGY OF LYMPH NODES IN HIV INFECTED PATIENTS

Lymphadenopathy is the commonest presentation in HIV positive individuals. Fine needle aspiration cytology of 196 HIV positive patients was studied during six monthly review. 75% paients in this study who were asymptomatic were detected to have lymphadenopathy during the surveillance. 82% had lymph nodes smaller than 1cm size. Lymphadenopathy at more than one site was observed in 46.8% cases. Commonest opportunistic infection noticed was tuberculosis (TB) in 34.2%. Cyto-morphologically reactive pattern with Add fast bacilli (AFB) positivity was observed in 16.4% of TB cases. In 2.9% cases AFB were detected even in the tissue fluid. Negative images of AFB were observed in the macrophages in 3 cases. TB was detected with equal frequency in both asymptomatic and symptomatic groups. Axillary nodes pose problem due to deeper location. False positives were a case of dermatopathic lymphadenopathy and a case of Kimura's disease. False negatives include two cases of TB lymphadenitis. Pathogens should be looked for irrespective of cyto-morphology. Biopsy should be done to confirm cases of lymphomas. Fine needle aspiration cytology should be included in the protocol of six monthly review of HIV infected cases.

Impact of inversion of the CD4/CD8 ratio on the natural history of HIV-1 infection

BACKGROUND

HIV-1 infection is characterized by an inverted CD4/CD8 T-cell ratio, but the distribution of inversions over time after seroconversion and whether delay of inversion is associated with a favorable prognosis are not known.

METHODS

T-cell counts and clinical outcomes among men in the Multicenter AIDS Cohort Study who had incident HIV-1 infection before December 31, 1995 were analyzed by Kaplan-Meier and Cox proportional hazards methods. Results were also analyzed by time-dependent multivariate methods to adjust for CD4 lymphocyte counts, viral loads, age, race, and polymorphisms in host chemokine receptor genes (CCR5-Delta32 and CCR2-64I).

RESULTS

Among 424 cases whose date of seroconversion was known to within +/-4.5 months, 317, 52, and 55 inverted their CD4/CD8 ratio within less than 1, 1 to 2, and more than 2 years of seroconversion, respectively. Longer time to inversion was significantly associated with longer time to AIDS, even after adjusting for CD4 lymphocyte count and viral load at the first seropositive visit and over the first 3 seropositive visits. Of the 6 seroconverters who had more than 500 CD4 lymphocytes 10 years after seroconversion without receiving highly active antiretroviral therapy, 5 took more than 2 years to invert their CD4/CD8 ratio.

CONCLUSIONS

Time from HIV-1 seroconversion to inversion of the CD4/CD8 ratio independently predicted time to AIDS. Early measurements of the CD4/CD8 ratio until inversion occurs may identify people likely to become long-term nonprogressors or slow progressors, thus facilitating detailed studies of the mechanism of HIV-1 disease progression.

Inverse correlation of telomerase activity/proliferation of CD4+ T lymphocytes and disease progression in simian immunodeficiency virus-infected nonhuman primates

Both increased lymphocyte renewal with subsequent exhaustion of the immune system and impaired T-cell renewal have been put forth to account for CD4+ T-cell depletion and development of AIDS in HIV-1-infected humans and SIV-infected nonhuman primates. In the present study, telomeric terminal restriction fragment length and telomerase activity were used as measures of proliferative activity of T lymphocytes from three nonhuman primate species before and after being infected with SIV. In peripheral blood T cells, our data show both species and T-cell-subset-specific differences in proliferative activity accompanied by different patterns of disease progression. A significant postinfection increase in telomerase/proliferative activity in CD4+ T cells from seropositive sooty mangabeys and from normal progressor rhesus macaques was associated with asymptomatic infection or delayed disease progression, respectively, whereas a decrease in telomerase/proliferative activity detected in CD4+ T cells postinfection from SIVsmmPBj14-infected pigtailed macaques was associated with rapid CD4+ T-cell depletion and disease progression. The levels of telomerase activity observed in CD4+ T cells from peripheral blood closely parallelled those seen in CD4+ T cells in lymph node samples from selected animals. Our data suggest that an increase in proliferative activity of T lymphocytes in vivo may be associated with a favorable course of SIV infection in nonhuman primates.

Signaling Through the Lymphotoxin-β Receptor Stimulates HIV-1 Replication Alone and in Cooperation with Soluble or Membrane-Bound TNF-α

The level of ongoing HIV-1 replication within an individual is critical to HIV-1 pathogenesis. Among host immune factors, the cytokine TNF-α has previously been shown to increase HIV-1 replication in various monocyte and T cell model systems. Here, we demonstrate that signaling through the TNF receptor family member, the lymphotoxin-β (LT-β) receptor (LT-βR), also regulates HIV-1 replication. Furthermore, HIV-1 replication is cooperatively stimulated when the distinct LT-βR and TNF receptor systems are simultaneously engaged by their specific ligands. Moreover, in a physiological coculture cellular assay system, we show that membrane-bound TNF-α and LT-α1β2 act virtually identically to their soluble forms in the regulation of HIV-1 replication. Thus, cosignaling via the LT-β and TNF-α receptors is probably involved in the modulation of HIV-1 replication and the subsequent determination of HIV-1 viral burden in monocytes. Intriguingly, surface expression of LT-α1β2 is up-regulated on a T cell line acutely infected with HIV-1, suggesting a positive feedback loop between HIV-1 infection, LT-α1β2 expression, and HIV-1 replication. Given the critical role that LT-α1β2 plays in lymphoid architecture, we speculate that LT-α1β2 may be involved in HIV-associated abnormalities of the lymphoid organs.