Is Neonatal Lupus Genetic?

Neonatal lupus is a rare, acquired, autoimmune, and congenital (present at birth) condition characterized by red rash or skin eruptions and heart issues.

The mother of the affected baby often does not have lupus but they carry certain antibodies that attack the cells in the body and may lead to several symptoms and complications in the infants.

Although the exact estimated ratio is not available, researchers believe that the condition is very rare and affects approximately 1 in every 20,000 infants.

Also called:

• Neonatal lupus erythematosus
• Congenital heart block
• Neonatal lupus syndrome

The exact underlying process by which the maternal autoantibodies affect the fetus is not completely understood yet and is under investigation. However, research suggests:

• Neonatal lupus is an acquired disorder, which means it develops when specific antibodies are passed from a pregnant woman to the developing fetus via the placenta.
• In most cases, the mother could be carrying antibodies referred to as anti-Ro (or SS-A) and anti-La (or SS-B) or both.
• Mothers of infants with neonatal lupus do not necessarily have lupus themselves. They may have anti-Ro or anti-La antibodies from different rheumatic disorders, such as Sjogren’s syndrome or rheumatoid arthritis.
• Antibodies are produced by the body’s immune system to fight foreign substances called antigens, which include microorganisms, toxins, and other such substances.
• Usually, during pregnancy, antibodies travel across the placenta from the mother to the bloodstream of the developing fetus because the fetus cannot make antibodies on its own.
• In neonatal lupus, certain antibodies called autoantibodies cross over the placenta that mistakenly damages specific fetal healthy tissues.

Some infants may develop only skin symptoms, whereas some may develop only heart symptoms. Rarely, some infants do develop both.

Most common symptoms include:

• Red, ring-like skin lesions resembling the rash associated with systemic lupus erythematosus
• Erythematous plaques are predominately on the scalp, neck, or face (typically periorbital in distribution) but may appear on the trunk or extremities
• The rash is temporary or transient and often develops during the first few weeks of life (about six weeks after birth)
• Raccoon eye pattern
• Abnormal sensitivity to sunlight (photosensitivity)
• Congenital heart block (conduction abnormalities may vary among affected infants: first, second, or third-degree blocks)

Other less common findings include:

• Liver diseases, such as cholestatic hepatitis (characterized by the reduced flow of bile from the liver), cholestasis (inflammation of the liver), hepatitis, and yellowing of the skin, mucus membranes, and whites of the eyes (jaundice)
• Macrocephaly (an abnormally large head circumference)
• Thrombocytopenia (low numbers of circulating blood platelets)
• Neutropenia (low levels of white blood cells)
• Anemia (low red blood cells)
• Splenomegaly (abnormally large spleen)
• Hepatomegaly (abnormally large liver)
• Hydrocephalus (excessive accumulation of cerebrospinal fluid in the skull that can put pressure on the tissues of the brain)

To diagnose neonatal lupus, along with thorough physical examinations and close attention to the cardiopulmonary status, the doctor will perform cutaneous (skin), cardiac, hepatobiliary, hematologic, and neurologic assessments.

Neonatal lupus begins before birth when these autoantibodies reach the baby via the placenta. The condition ends within the first few months of life because the autoantibodies disappear from the baby’s system.

The symptoms, such as skin rashes and low blood cell counts, are transient and usually go away after six months with no long-term consequences. However, neonatal lupus does have the potential to cause permanent damage to the baby’s heart called heart block between 18 and 24 weeks of their life.

This condition does not disappear and if the heart block is significant, the affected infant will eventually need a pacemaker to prevent further complications.

The most significant potential complication of neonatal lupus is a heart condition called congenital heart block due to problems in the electrical system of the baby's heart. If this is not resolved within the first few months of life, infants may ultimately require a pacemaker.

In some cases, heart block may lead to syncope (fainting or passing out), severe breathlessness, and arrhythmias (irregular heartbeats).

Some infants may develop a disease of the heart muscle called cardiomyopathy, which can occur in association with thickening within the muscular lining of the heart chambers due to an increase in the amount of supporting connective tissue and elastic fibers (endocardial fibroelastosis).

There can be abnormalities of the mitral and tricuspid valves.

Additionally, cardiac abnormalities have been reported to cause myocarditis (inflammation of the myocardium, which are the muscles of the heart).

In severe cases, life-threatening complications, such as heart failure or sudden cardiac arrest, can potentially develop with substantial-associated morbidity and mortality in up to 65 percent of patients.