Pregnancy Complicated With Sjögren Syndrome

Author Information

Sharma K*, Chauhan AR**.

(* Senior Resident, ** Professor, Department of Obstetrics and Gynecology, Seth G.S. Medical College and K.E.M. Hospital, Mumbai, India).

Abstract

This is a case of pregnancy complicated with Sjögren syndrome (anti Ro antinuclear antibodies) with a past history of hypokalemic paralysis and distal renal tubular acidosis (dRTA). Patient was successfully managed by a multidisciplinary approach, had a preterm delivery and was discharged with a healthy baby.

Introduction

Sjögren syndrome is an autoimmune disease characterized by the presence of autoimmune antibodies which cause destruction of salivary and lacrimal glands, primarily resulting in dry eyes and dry mouth.[1]  If Sjögren syndrome occurs primarily it is called primary Sjögren syndrome, and if it occurs in association with other connective tissue disorders it is called secondary Sjögren syndrome.[2]

Case Report

Our patient 28-year-old primigravida with 32 weeks gestation presented to the emergency room with pain in abdomen. Pregnancy up to this point was uneventful. Patient’s general examination was normal. On per abdomen examination, uterus was 30 weeks gestation and relaxed with normal liquor and a normal regular fetal heart rate. On per vaginal examination, os was closed, posterior and uneffaced.

Patient was diagnosed in 2013 as a case of Sjögren syndrome when she had an episode of hypokalemic paralysis and facial palsy, at which time her potassium level was 2.9 mEq/ l (normal value 3.5- 5 mEq/ l). On investigation at that time, it was found that hypokalemia was due to distal renal tubular acidosis (dRTA). USG done showed left renal stone which was due to hypercalciuria and hyperphosphaturia which is a feature of dRTA. Patient was found to have hypothyroidism, Raynaud’s phenomena and dRTA with presence of antinuclear antibody (ANA) and anti SS-A Ro and anti SS-B La antibodies pointing towards diagnosis of Sjögren syndrome. She was treated in the ICU and was on ventilator support. She was advised confirmatory tests like Schimer’s test and lip biopsy but she did not get them done. She recovered completely but was lost to follow up and stopped all her medications on her own. 

In the current pregnancy, patient was admitted and investigated; case was reviewed by physician, endocrinologist, rheumatologist and obstetrician. In her present reports, VBG (venous blood gas) showed a pH of 7.35 (normal 7.35-7.45), potassium level was 3.9 mEq/ l, bicarbonate was 13 mEq/ l (normal 7-13 mEq/ l) and urine calcium to creatinine ratio was 0.26 (normal <0.2). Her USG abdomen showed no renal stones. Her urine routine and vaginal swab were normal ruling out any source of infection. Her 2 D echocardiography was normal and ENT and ophthalmological examination were normal ruling out systemic complications if any. ANA blot was done which was strongly positive for anti SSA Ro antibodies. Her obstetric USG showed a single live intrauterine pregnancy of 30 weeks with normal liquor and no IUGR, with normal Doppler. The fetal 2D echocardiography was normal with no conduction defects; anomaly scan was also normal. She was started on tablet aspirin 75 mg daily, tab hydrochloroquine 200 mg daily, tab thyroxine 75 µg daily, syrup potassium chloride 10 ml thrice a day, along with calcium, vitamin D and hematinics.  She was given steroids for fetal lung maturity. She was advised to have coconut water and fruit juices which are potassium rich. Patient remained asymptomatic and was discharged on request with the instructions for medications and weekly serum potassium monitoring.  She presented in active labor at 35 weeks gestation and delivered vaginally a preterm male child with birth weight of 1.68 kg.  Baby was admitted in NICU and discharged on day 6, along with the mother. On discharge patient was reviewed by various departments and advised to continue syrup potassium chloride and calcium supplements.

Discussion

Sjögren syndrome is basically a genetic defect which is precipitated by environmental triggers like viral and bacterial infections. It is more common in females. Estrogen in females might affect immune system in body increasing susceptibility to this syndrome.[3]  The diagnosis of Sjögren syndrome is based on symptomatology.  Antibodies like ANA and Rh factors which are indicative of autoimmune disorders are present in this syndrome. ANA is the most commonly detected antibody and anti SSB LA is the most specific. A lip or salivary gland biopsy that reveals lymphocytic infiltration around salivary gland is diagnostic of the condition. In our patient ANA and anti Ro and La antibodies were positive. Lip biopsy was proposed but patient refused the same. Sjögren syndrome does not impair fertility but patients experience more complications during pregnancy compared to normal controls. The course and outcome of pregnancy has not been extensively studied as the syndrome occurs mostly in perimenopausal and post-menopausal women. This syndrome may sometimes be complicated with pulmonary hypertension specially during pregnancy and post-partum period. Effect of auto immune disease on pregnancy depends on various factors like disease activity, severity of organ damage, antibody profile and drug treatment.[4]  There is an increased risk of spontaneous abortions and fetal loss.[5]  The rate of preterm deliveries and IUGR is also higher in these patients.[6]  IUGR and fetal distress increases the rate of cesarean delivery in affected cases.[7] These adverse fetal effects are due to presence of immunological factors like SSA, SSAB and APLA antibodies. Neonatal lupus and congenital heart block (CHB) are the most common fetal manifestations. CHB results from damage of atrioventricular node caused by anti SSA and SSB antibodies. Incidence of CHB in anti SSA affected pregnancy is 1- 2 %. Cases of Sjögren syndrome affected pregnancies are managed by multidisciplinary approach.[8]  Prenatal counseling of affected women must be done explaining the maternal and fetal manifestations of the disease. Ideally disease should be well in control 3 to 6 months prior to conception. During antenatal period, serial 2 D echocardiogram should be done starting from 16- 20 weeks to detect CHB as early as possible. Monitoring of fetal wellbeing by serial USG is advised for early detection of IUGR and other fetal manifestations. 

Fluorinated corticosteroids like dexamethasone and betamethasone are the most commonly used drugs. These decrease the load of maternal antibodies which in turn reduces placental transfer of these antibodies. These steroids can also cross the placenta to reach the fetus and reduce inflammatory damage and fibrosis of atrioventricular node thus preventing CHB.[9] Renal involvement in the mother is seen in 4.2 to 50 % cases. Distal RTA is the most common renal manifestation seen in 25 % cases of Sjögren syndrome.[10]  Hypokalemia is the most common electrolyte disorder caused by increased potassium secretion by distal tubular cells in setting of diminished H+ ion secretion.  Hypokalemia in distal RTA is usually not very severe but in a few cases can cause hypokalemic periodic paralysis and hypokalemic cardiac arrhythmias. Hypokalemic paralysis, though very rarely, can present as primary manifestation of Sjögren syndrome as seen in our case. There is hypercalciuria and hyperphosphatemia in distal DTA due to reduction in calcium absorption secondary to chronic acidosis and due to increased calcium phosphate release from bones due to bone buffering of excess acid. All these can result in recurrent renal stones, bone pain and osteomalacia. RTA and hypokalemia are treated with potassium citrate and sodium bicarbonate. Our case is one of the very rare cases of pregnancy with Sjögren syndrome complicated with distal RTA and hypokalemia. Our patient was treated with potassium syrup and recovered completely without any recurrence of symptoms.

References

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Citation

Sharma K, Chauhan AR. Pregnancy Complicated With Sjögren Syndrome. JPGO 2017. Volume 4 No.7. Available from: http://www.jpgo.org/2017/07/pregnancy-complicated-with-sjogren.html