Mechanisms of immunomodulatory action of intravenous immunoglobulin in autoimmune and systemic inflammatory diseases

Intravenous immunoglobulin treatment during pregnancy and the post-partum period in women with multiple sclerosis: A prospective analysis

Background

Relapsing-remitting multiple sclerosis (RRMS) affects predominantly young women within reproductive years. As an increased risk of relapses is known to occur during the post-partum period, it is important to consider treatment options.

Aim

Evaluate the effects of intravenous immunoglobulins (IVIg) to prevent post-partum relapses.

Methods

We prospectively followed 198 pregnant female RRMS patients, 67 treated with IVIg during pregnancy and the three months post-partum, and 131 untreated patients that served as controls.

Results

During the pre-gestation year, 41.4% were treated with immunomodulatory drugs, and 28.3% experienced a relapse. During pregnancy and the post-partum period, the number of relapsing patients significantly decreased in the IVIg group (37.3%, 10.4%, 8.9%, respectively, p = 0.0003), while no significant change was observed in the untreated group (23.7%, 17.6%, and 22.1%). During the three-month post-partum period, there were only mild and moderate relapses in the IVIg group, while in the untreated group, there were also severe relapses. Stepwise logistic regression that assessed the relation between three-month post-partum relapse and explanatory variables demonstrated that untreated patients had increased risk for post-partum relapse (odds ratio = 4.6, 95% CI [1.69, 12.78], p = 0.033).

Conclusions

IVIg treatment proved efficient to reduce the rate and severity of relapses during pregnancy and the three-month post-partum.

Immunoglobulin for Treating Bacterial Infections: One More Mechanism of Action

The mechanisms underlying the effects of immunoglobulins on bacterial infections are thought to involve bacterial cell lysis via complement activation, phagocytosis via bacterial opsonization, toxin neutralization, and antibody-dependent cell-mediated cytotoxicity. Nevertheless, recent advances in the study of the pathogenicity of Gram-negative bacteria have raised the possibility of an association between immunoglobulin and bacterial toxin secretion. Over time, new toxin secretion systems like the type III secretion system have been discovered in many pathogenic Gram-negative bacteria. With this system, the bacterial toxins are directly injected into the cytoplasm of the target cell through a special secretory apparatus without any exposure to the extracellular environment, and therefore with no opportunity for antibodies to neutralize the toxin. However, antibodies against the V-antigen, which is located on the needle-shaped tip of the bacterial secretion apparatus, can inhibit toxin translocation, thus raising the hope that the toxin may be susceptible to antibody targeting. Because multi-drug resistant bacteria are now prevalent, inhibiting this secretion mechanism is an attractive alternative or adjunctive therapy against lethal bacterial infections. Thus, it is not unreasonable to define the blocking effect of anti-V-antigen antibodies as the fifth mechanism for immunoglobulin action against bacterial infections.

Follow up of children after antenatal treatment for alloimmune thrombocytopenia

OBJECTIVE

To evaluate the long-term follow-up of surviving offspring after antenatal treatment for fetal or neonatal alloimmune thrombocytopenia (FNAIT).

PATIENTS

Fifty children at risk of FNAIT were antenatally treated with maternal intravenous immunoglobulins (IVIG) (n=11), IVIG with intrauterine platelet transfusions (IUPT) (n=26) or IUPT alone (n=9). In four cases (n=4), only fetal blood sampling (FBS) was performed. One child died in the neonatal period and one was lost to follow up.

METHODS

The remaining 48 children, aged 1.3-11.6 years (median 5.1 years), were given both general and neurological examinations and assessed on their development and susceptibility for infections or atopic constitution. In addition, immunoglobulin levels were measured in 17 infants, aged 5 years and older.

RESULTS

Intracranial hemorrhage (ICH) was not observed. The general health and neurodevelopmental outcome in the children was comparable to a normal Dutch population. Children not exposed to maternal IVIG treatment had significantly more infections and hearing problems than children exposed to IVIG treatment or the normal population. Immunoglobulin G, A and M levels were within the normal range, independent of treatment and severity of FNAIT. A high IgE level was more frequently seen in children exposed to IVIG, but did not result in clinical consequences such as allergy or atopy.

CONCLUSIONS

Antenatal treatment of children for FNAIT did not affect general health or neurodevelopmental outcome. In particular, exposure to IVIG in utero showed no adverse effect on the clinical outcome of these children.