Persistently high IgA serum levels are a marker of immunological or virological failure of combined antiretroviral therapy in children with perinatal HIV-1 infection

Association between different anti-Tat antibody isotypes and HIV disease progression: data from an African cohort

BACKGROUND

The presence of IgG and IgM against Tat, an HIV protein important for viral replication and immune dysfunction, is associated with slow disease progression in clade B HIV-infected individuals. However, although Tat activities strictly depend on the viral clade, our knowledge about the importance of anti-Tat antibodies in non-clade B HIV infection is poor. The objective of this study was to investigate the association of different anti-Tat antibody isotypes with disease progression in non-clade B HIV-infected subjects and to study the relationship between anti-Tat humoral responses and immunological abnormalities.

METHODS

Anti-clade B and -clade C Tat IgG, IgM and IgA titers were assessed in serum samples from 96 cART-naïve subjects with chronic HIV infection from Mbeya, Tanzania, and associated with CD4(+) T cell count, plasma viremia and CD4(+) and CD8(+) T cell phenotypes.

RESULTS

Anti-Tat IgM were preferentially detected in chronic HIV-infected subjects with low T cell activation (p-value = 0.03) and correlated with higher CD4(+) T cell counts and lower viral loads irrespective of the duration of infection (p-value = 0.019 and p-value = 0.037 respectively). Conversely, anti-Tat IgA were preferentially detected in individuals with low CD4(+) T cell counts and high viral load (p-value = 0.02 and p-value < 0.001 respectively). The simultaneous presence of anti-Tat IgG and IgM protected from fast CD4(+) T cell decline (p-value < 0.01) and accumulation of CD38(+)HLADR(+)CD8(+) T cells (p- value = 0.029).

CONCLUSIONS

Anti-Tat IgG alone are not protective in non-clade B infected subjects, unless concomitant with IgM, suggesting a protective role of persistent anti-Tat IgM irrespective of the infecting clade.

Long-term effect of highly active antiretroviral therapy on immunologic features in children

BACKGROUND

Highly active antiretroviral therapy (HAART) has transformed human immunodeficiency virus infection (HIV) into a chronic condition. The effects of long-term HAART on the immune system activity of early infected children are not fully understood. Hence, the aim of this review is to investigate immune system recovery and residual alteration in HIV-infected children receiving HAART in high-income countries.

METHODS

A systematic review was performed by searches of PubMed and references of the relevant articles. Studies published between January 1, 2000 and April 1, 2014 and conducted in high-income countries reporting data on immunological features in HIV-infected children receiving HAART were included in this review.

RESULTS

Fifty-three articles were included in this review. Present knowledge on B-cell and T-cell function, immunoglobulin production, response to vaccine and innate immune system activity in HIV-infected children receiving HAART is discussed.

CONCLUSION

Starting therapy as soon as diagnosis is ascertained and monitoring vaccine response in children under HAART are the most important tools to safeguard immunological function in HIV-infected children.

Low prevalence of selective IgA deficiency in infected children born to HIV-seropositive mothers: an in vivo model for speculation on selective IgA deficiency pathogenesis

Anecdotal reports of restored immunoglobulin production in individuals with common variable immunodeficiency after acquiring HIV infection suggest that perturbation of the immune system occurring during HIV infection may force some underlying functional defects. These findings raise intriguing questions about the pathogenesis of common variable immunodeficiency. No study has investigated the possible influence of HIV infection on the development of selective IgA deficiency, a primary immunologic defect genetically related to common variable immunodeficiency. IgA serum levels were evaluated in a large cohort of children born to HIV-infected mothers from 1985 to 2006. To avoid differences possibly due to different follow-up durations we considered only infected and non-infected children aged over 4 years at last-follow-up. The study included 1,157 non-infected children and 964 infected children, aged ≥ 4 years at last-follow-up and with availability of two or more serum IgA determinations over six months of age. No child displayed immunoglobulin values compatible with diagnosis of common variable immunodeficiency. However, 0/964 infected children vs. 5/1157 non-infected children had selective IgA deficiency (P=0.048). It may be speculated that several immunological alterations, occurring simultaneously in perinatal HIV infection, surpass the functional defect exhibited in some children with selective IgA deficiency. Our data may shed light on the pathogenesis of selective IgA deficiency.

Treatment of pediatric HIV infection

HIV-infected children require a peculiar management when compared to infected adults. Antiretroviral therapy has been quite well adapted to children, but new studies are needed to answer many unsolved questions, such as when to start therapy in asymptomatic infected children. Recently, several guidelines have been updated. In this review, we compare these recommendations together with the latest studies concerning the treatment of HIV in children. A triple-drug combination therapy based either on nonnucleoside reverse transcriptase inhibitors or protease inhibitors is the recommended initial therapy. After treatment failure, a second-line therapy should be based on switching between these two regimens. Antiretroviral therapy should be managed by an expert in pediatric and adolescent HIV infection. The importance of children's adherence to therapy is a crucial point, particularly in adolescents.