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5TH NATIONAL CONFERENCE OF PEDIATRIC RHEUMATOLOGY, KOLKATA, 29TH & 30TH SEPTEMBER 2007
Tapas Sabui
Associate Professor
Pediatrics, NRS Medical College
Kolkata
Madhumita Nandi
Clinical Tutor
IPGMER, Kolkata
The neonatal lupus syndromes (NLS), while quite rare, carry significant mortality and morbidity. Although it is classically believed that the disease is due to transplacental passage of maternal antinuclear antibodies, they are not sufficient to directly cause cardiac scarring. It seems genetic factors are likely to have role in clinical expression. Mothers with HLA DR3 are at increased risk of delivering babies with NLS. Clinical manifestations occur usually within the first 2 months of life. It is characterized by presence of anti SSA/Ro and SSB and/or U1 RNP antibody both in baby and mother. Target organs are heart, skin, liver, blood and gastrointestinal tract. All clinical manifestations are usually transient except cardiac complications. Cardiac manifestations include complete (classical) or incomplete heart block (CHB) in a structurally normal heart, immune myocarditis, dilated cardiomyopathy and endomyocardial fibroelastosis. Only 2% of fetuses born to mothers with maternal SLE/Connective tissue disorder develop CHB and majority of mothers are usually asymptomatic. The recurrence rate of CHB in subsequent pregnancies is 19%. Once CHB/NLS is suspected in a fetus, echocardiography should be done weekly from 16 to 26 weeks and every other week until about 34 weeks. Until recently, in utero detection of first degree block was not technically feasible. However, the EKG equivalent of the PR interval can now be measured by echocardiography (Mechanical PR). Intervention at this stage with glucocorticoids may decrease acute inflammation but not necessarily prevent subsequent fibrosis.
50% of patients suffer from dermatological complications. Skin lesions are photosensitive and characterized classically by annular erythematous scaling plaques. It frequently involves the face and scalp with characteristic predilection for upper eyelids. Rash is rarely present at birth. Hematological manifestations include thrombocytopenia, immune hemolytic anemia and neutropenia. Incidence of hepatobiliary disease is 19%. Three common clinical presentations are severe hepatic failure, conjugated hyperbilirubinemia with mild or no rise of aminotransferases and asymptomatic mild rise of aminotransferases levels.
Risk factors for death are a fetal diagnosis, the presence of hydrops, gestational age under 33 weeks or the development of endocardial fibroelastosis (EFE) with ejection fraction 40%. Outcome is directly related to heart rate and inversely proportional to it. Heart rate 50 is associated with 50% mortality and all survivors require permanent pacing. Heart rate 60 is associated with a mortality of 6% and 20% of survivors require cardiac pacing. EFE occurs despite adequate cardiac pacing and is associated with significant mortality, whether developing in fetal or postnatal life.
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