Presentation of case
Dr. A. Lueger:
The patient came to Austria as a refugee during the Yugoslav Wars 25 years ago. She was in the 7th week of pregnancy when her husband brought her to the emergency room (ER) of the Graz University Medical Center at 3 o’clock in the morning due to increasing dyspnea. She also complained of a dry cough but there was no fever. She had had a miscarriage 7 months previously and 3 years earlier, the patient had had a cesarean section at 40 weeks of gestation due to fetal distress. A healthy infant was delivered, weighing 3290 g and measuring 52 cm in length. At that time the hemoglobin before the cesarean section was 11.0 g/dL (normal: 12.0–15.3 g/dL), the mean corpuscular volume (MCV) was 82.8 fL (normal: 80–98 fL) and hemoglobin after delivery was 9.2 g/dL. On the current admission, she did not complain of any pain and there was no history of a vaginal discharge. She had no known allergies, and the only medication she took was oral replacement of folic acid and iron. Iron deficiency was said to have been present since youth but was never investigated. The electronic hospital record system also showed that she had come to the ER 16 months prior to admission because of fatigue, lassitude and exhaustion. The hemoglobin then was 10.4 g/dL, serum iron was 16 µg/dL (normal: 50–160 µg/dL) and ferritin 6 ng/mL (normal: 30–150 ng/mL). She received intravenous iron, and a work-up of the anemia was recommended, but not pursued by the patient. Physical examination revealed a slimly built person (55 kg, 170 cm, body mass index, BMI 19.0 kg/m2), blood pressure 110/80 mm Hg, heart rate 140 bpm, temperature 37.2 °C, O2 saturation 100% in room air and pale skin. There was no pulmonary or cardiac abnormality. Electrocardiogram showed sinus tachycardia. Laboratory results: hemoglobin 8.3 g/dL, MCV 60.3 fL, reticulocytes 13.9 ‰ (normal: 5–20 ‰), leukocytes 9.6 × 109/L (normal: 4.4–11.3 × 109/L), platelets 322 × 109/L (normal: 140–440 × 109/L), albumin 3.1 g/dL (normal: 3.5–5.3 g/dL), serum iron 10 µg/dL, transferrin 1.73 g/L (normal: 2.0–3.6 g/L), transferrin saturation 4% (normal: 16–45%), ferritin 11 ng/mL, vitamin D 8.1 ng/mL (normal: 30–60 ng/mL), parathyroid hormone 117.3 pg/mL (normal: 15–65 pg/mL), osteocalcin 98.0 ng/mL (normal: 1.0–35.0 ng/mL), prothrombin time 14% (normal: 70–120%), international normalized ratio (INR) 4.73 (normal: 2–3.5), activated partial thromboplastin time (APTT) 88.9 s (normal: 26–36 s), fibrinogen 606 mg/dL (normal: 210–400 mg/dL), antithrombin (AT) 108% (normal: >75%), D‑dimer 0.67 mg/dL (normal: <50 mg/dL), factor II 20% (normal: >70%), factor V 102% (normal: >70%), factor XI 59% (normal: >50%), factor XII 73% (normal: >50%), haptoglobin 2.84 g/L (normal: 0.3–2.0 g/L), folic acid 3.6 ng/mL (normal: 2.7–34.0 ng/mL), vitamin B12 531 pg/mL (normal: 180–1100 pg/mL), C‑reactive protein (CRP) 62.4 mg/dL (normal: <5.0 mg/dL), thyroid-stimulating hormone 0.62 µU/mL (normal: 0.27–4.2 µU/mL). The patient received intravenous iron and vitamins K and D. Her levels of hemoglobin (12.8 mg/dL), MCV (85.5 fL) and ferritin (38 ng/mL) normalized within 3 weeks and so did prothrombin time and the serum vitamin D level. The remainder of the pregnancy was uneventful.
A diagnostic test was performed.
Differential diagnosis
Dr. C. Tinchon:
The patient under discussion is a young woman with increasing dyspnea and anemia in the 7th week of pregnancy. Anemia is a common condition in pregnancy and is defined as a hemoglobin level <11 g/dL in the first trimester and below 10.5 g/dL in the second and third trimester [
1‐
3]. It affects up to 40% of pregnant women worldwide and nearly one third in the USA [
4,
5]. It is a risk factor associated with antepartum, intrapartum and postpartum maternal morbidity, and perinatal morbidity and mortality with adverse effects arising proportionally to the severity of anemia [
6]. The topic of anemia in pregnancy is complex and there is a wide variety of potential underlying etiologies that should be considered (Table
1). However, physiologic anemia (dilutional) and iron deficiency are the two most common causes of anemia in pregnant women. Physiologic anemia is due to an increase in plasma volume by 10–15% at weeks 6–12 of gestation with a further rapid expansion by weeks 30–34, and plateauing or slightly decreasing toward term. All of this occurs despite an adequate increase in red blood cell mass. At term, the total plasma volume of 4700–5200 mL is about 30–50% above that in non-pregnant women, while the increase in red cell mass is only about 10–30% [
7]. This physiologic fall in hemoglobin concentration across pregnancy is often quoted as 5 g/L, but it was found to be as high as 8 g/L in some studies [
8]. Insufficient supply of iron and micronutrients, such as folate, vitamins B
12, B
6 and copper due to inappropriate intake, hyperemesis gravidarum or malabsorption may also contribute to an imbalance between availability and increased nutrient requirements for fetal red blood cell production and fetoplacental growth, and consequently result in anemia. Iron deficiency is the most common cause of anemia worldwide and affects about one in three pregnant women [
9,
10]. Laboratory data of the discussed patient showed significantly reduced levels of all iron status parameters (serum iron, transferrin saturation and ferritin) and confirmed the diagnosis of iron deficiency. However, this condition has been known for many years in this patient and could not be improved by regular oral iron supplementation. Assessment of iron status is sometimes challenging. Thus, the markedly reduced transferrin levels observed in the discussed patient may hint at malnutrition, protein deficiency, zinc deficiency, chronic liver injury or conditions, such as acute phase reactions, chronic disease or hereditary hypotransferrinemia [
11]. Iron deficiency may be due to increased loss (gastrointestinal or urogenital bleeding, epistaxis, blood donation, hemoglobinuria caused by intravascular hemolysis), malnutrition, malabsorption, relative iron deficiency during therapy with erythropoietin, infection with
Helicobacter pylori, or increased physiologic needs. Microcytic anemia may further be caused by chronic inflammation with a subsequent increase in hepcidin [
12], which is an acute phase protein and hormone, and as such is a key regulator of systemic iron balance [
13]. It inhibits iron entry into the plasma compartment from the three main sources of iron, i.e. dietary absorption in the duodenum, the release of recycled iron from macrophages and the release of stored iron from hepatocytes [
13,
14]. Less frequently, microcytic hypochromic anemia may be sideroblastic (hereditary or acquired due to deficiencies in vitamin B
6 or copper, or due to lead poisoning) and in rare cases it may be caused by thalassemia, sickle cell disease, or it may present as inherited atypical form of microcytic anemia. In the presence of fragmentocytes, microcytic hypochromic anemia may be artificial, i.e. resulting from hyponatremia.
Table 1
Causes of different forms of anemia in adults. (Adapted from [
7])
Low or normal | Iron deficiency Anemia of chronic disease/inflammation Sideroblastic anemia Copper deficiency Vitamin B6 deficiency Zinc deficiency | Bleeding (acute) Iron deficiency (early) Anemia of chronic disease/inflammation Bone marrow suppression (cancer, aplastic anemia, infection) Chronic renal insufficiency Hypothyroidism Hypopituitarism Excess alcohol | Vitamin B12 or folate deficiency Excess alcohol Myelodysplastic syndrome Liver disease Hypothyroidism HIV infection Medications that interfere with nuclear maturation |
Increased | Thalassemia Hemolysis | Bleeding (with bone marrow recovery) Hemolysis Bone marrow recovery (e.g. after infection, vitamin B12 or folate replacement and/or iron replacement) | Hemolysis Bone marrow recovery (e.g. after infection, vitamin B12 or folate replacement and/or iron replacement) |
Other causes of anemia besides physiologic factors and iron deficiency that are much less common but should be mentioned in the context of pregnancy include hemolytic anemia due to HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS); however, in the discussed patient these diagnoses can be ruled out because of lacking clinical and laboratory findings suggesting these conditions (Table
2).
Table 2
Comparison of TTP, HUS and HELLP syndrome with regard to symptoms and laboratory findings [
15,
16]
Abdominal pain | ++ | ++ | ++ |
Low ADAMTS-13 activity | +/++ | – | −/+ |
Anemia | ++ | ++ | + |
Elevated LDH | ++ very high values | ++ very high values | ++ |
Elevated transaminases | −/+ | −/+ | ++ |
Fever | + | – | – |
Headache or visual disturbance | ++ | – | ++ |
Hypertension | +/++ | ++ | ++ |
Jaundice | – | – | + |
Nausea and vomiting | ++ | ++ | ++ |
Proteinuria | + and hematuria | ++ | ++ |
Thrombocytopenia | ++ | ++ | ++ |
Von Willebrand factor | ++ | ++ | – |
Laboratory data further revealed severe vitamin D deficiency with subsequently increased levels of parathyroid hormone and osteocalcin, and deficiency in vitamin K reflected by low levels of clotting factors II, VII, IX and X, predisposing to bruising and hemorrhage. Besides deficiencies in iron, vitamins D and K, the discussed patient also presented with low levels of albumin and transferrin, suggesting a deficiency in protein. Together with a low BMI, all these findings strongly hint at malnutrition or malassimilation, i.e. maldigestion or malabsorption. While maldigestion is due to reduced hydrolysis of nutrients (luminal or at the brush border level), malabsorption may be caused by (1) luminal factors (e.g. impaired hydrolysis, impaired micelle formation, limited bioavailability, bacterial overgrowth), (2) mucosal factors (impaired brush border hydrolase activity, inherited deficiencies, damaged absorbing surface, decreased absorbing surface, surgery, infiltration or infection), or (3) postabsorptive factors (e.g. obstruction of lymphatic system, deficiency in chylomicrons or beta-lipoproteins, protein-losing enteropathy) [
17]. However, chronic iron deficiency and low serum folate levels despite regular supplementation strongly suggest a malabsorption problem in this patient.
Since the patient presented without diarrhea (silent malabsorption), we can exclude liver diseases with disturbed enterohepatic bile acid circulation as a differential diagnosis. Due to a negative history, we can rule out drugs that may cause diarrhea (e.g. olmesartan [
18], mycophenolate mofetil, colchicine, cholestyramine, neomycin, calcium carbonate), tropical sprue (negative travel history), severe malabsorption syndromes in childhood (e.g. disaccharidase deficiency, Hartnup’s disease, cystinuria, acrodermatitis enteropathica, alpha-beta-lipoproteinemia, cystic fibrosis), surgery of the gastrointestinal tract (e.g. short bowel syndrome, bypass, fistulas), radiation (radiation enteritis), allotransplantation, inactivation of pancreatic enzymes due to Zollinger-Ellison syndrome, immunodeficiency syndromes and isolated fat malabsorption syndromes, such as benign familial hypobetalipoproteinemia. Because of lacking clinical symptoms and laboratory findings, chronic pancreatitis (which causes abdominal pain in up to 80% of patients and maldigestion in about 20% of patients, but not iron deficiency anemia), intestinal lymphoma, chronic merenteric ischemia and vasculitis can be excluded as a diagnosis in this pregnant patient. Since the patient did not complain of diarrhea, conditions such as a neuroendocrine tumor, infection with amoeba,
Trichuris trichiura (whipworm) or cryptosporidium parasites, autoimmune enteropathy, intestinal amyloidosis, mastocytosis and non-celiac gluten sensitivity are unlikely in this case. Moreover, the absence of edema rules out protein-losing enteropathy as the underlying pathology, while absent eosinophilia makes eosinophilic gastroenteritis or infestation with hookworms
Strongyloides stercoralis, Paragonimus spp. or
Schistosoma spp. an improbable diagnosis [
19]. As a differential diagnosis of malabsorption, Whipple‘s disease, a rare chronic infection in which almost all organ systems can be invaded by the rod-shaped bacterium
Tropheryma whipplei, should be considered as well.
Tropheryma whipplei is a ubiquitous bacterium with a wide clinical spectrum of infections encompassing chronic systemic infection (classical Whipple’s disease), chronic focal infections, acute infections and healthy carriage [
20]. The annual incidence in central European countries is estimated to be approximately 1/1,000,000 [
21]. It primarily affects middle-aged white men. The main clinical features include gastrointestinal symptoms, such as diarrhea and abdominal pain, joint symptoms and weight loss. Up to 60% of affected patients complain of recurrent arthritis, and up to 40% suffer from sacroiliitis [
22]. Furthermore, involvement of the central nervous system, cardiac manifestations (endocarditis) and pulmonary infiltration have all been described [
23]. Although the laboratory data showed a markedly increased level of CRP, which would also be typical for Whipple’s disease, the clinical features of the patient did not suggest this rare disorder. In addition, small intestinal bacterial overgrowth and infection with
Diphyllobothrium latum can be ruled out in this case because both conditions would go along with vitamin B
12 deficiency, which was not present in our patient.
Once considered a pediatric problem, celiac disease has now become an important differential diagnosis in adults as well. Celiac disease, also known as celiac sprue, nontropical sprue or gluten-sensitive enteropathy, is a chronic enteropathy characterized by an autoimmune response in genetically susceptible individuals that affects people of all ages worldwide [
24]. In western countries, the prevalence of celiac disease is about 1% of the general population [
25,
26]. Classical celiac disease diagnosed in children typically presents with diarrhea, malabsorption, failure to thrive and growth retardation [
27]. In adults, the clinical presentation of celiac disease can vary from the asymptomatic state to malabsorption, micronutrient deficiencies, osteoporosis and neurological disorders ([
28]; Table
3). Due to malabsorption of micronutrients, anemia and osteopenia or osteoporosis can most often be found in patients with newly diagnosed celiac disease. Anemia, usually secondary to iron deficiency and often refractory to oral iron treatment, affects 60–80% of newly diagnosed patients [
29‐
31], and about 75% of patients have some degree of bone loss [
32‐
34]. Therefore, it is recommended to obtain celiac antibodies whenever there is a clinical or biochemical suspicion of malabsorption [
35]. Serological testing includes anti-tissue transglutaminase (tTG-IgA) antibodies and anti-endomysial antibodies (EmA-IgA), detected by immunofluorescence, with equivalent diagnostic accuracy. The anti-gliadin antibody (AGA) test is less reliable; however, it is suggested that IgG and IgA antibodies against deamidated gliadin peptides (DGP)-AGA have a comparable diagnostic accuracy as tTG-IgA [
36,
37]. An IgA deficiency is about 10–15 times more common in patients with celiac disease than in healthy individuals. Genetic testing of HLA-DQ2 and HLA-DQ8 is not an absolute requirement for diagnosis, but a negative result makes celiac disease unlikely. In Europe, 85–90% of patients with celiac disease are positive for HLA-DQ2, and 10–15% are positive for HLA-DQ8 [
38]. However, it should be considered that 30–40% of the general population are also positive for these alleles (with HLA-DQ2 more common than HLA-DQ8) but do not have the disease [
39]. HLA testing needs to be performed only once during the lifetime, initial negative serological tests, however, do not exclude the development of celiac disease later in life. Histopathological changes are characterized by typical architectural abnormalities as defined by the Marsh-Oberhuber classification ([
40]; Table
4). Although gluten-free diet usually results in good clinical response, abnormal histopathological findings persist in a high percentage of patients [
41,
42]. Nevertheless, for the diagnosis of celiac disease, it is important that serological and histological diagnostic tests are performed while the patient is on a gluten-containing diet because otherwise the tests may be inconclusive and necessitate a gluten challenge.
Table 3
Different presentations of celiac disease in adults. (Adapted from [
24,
53])
Villous atrophya | − | + | + | + |
Serology (tTG-IgA)a | + | + | + | + |
HLA-DQ2 or DQ8 | + | + | + | + |
Nonspecific symptomsb | − | − | + | +/− |
Chronic diarrhea, steatorrhea | − | − | − | + |
Table 4
Marsh-Oberhuber classification of architectural abnormalities in celiac disease [
40]
Marsh | 0 | 1 | 2 | 3a | 3b | 3c |
IEL/100 epithelial cells | ≤25 | >25 | >25 | >25 | >25 | >25 |
Crypts | Normal | Normal | Hyperplasia | Hyperplasia | Hyperplasia | Hyperplasia |
Villus | Normal | Normal | Normal | Moderate atrophy | Subtotal atrophy | Total atrophy |
Type of lesion | Remission | Infiltrative | Hyperplastic | Destructive | – | – |
An entity that is less frequently observed in western countries but should nevertheless be mentioned as a differential diagnosis in this case, is infection with
Giardia lamblia. This protozoan parasite attaches to the intestinal epithelium in the duodenum and jejunum, and disrupts the epithelial barrier function by altering tight junction composition and increasing apoptosis [
43]. Symptoms of acute infection include abdominal pain, diarrhea, bloating and greasy stools that tend to float; indigestion or nausea and vomiting are also frequently reported [
44‐
46]. In chronic giardiasis, symptoms fluctuate and steatorrhea may be due to the formation of a layer of
Giardia trophozoites that are attached to the duodenal mucosa by a large ventral sucking disk. Besides the described cellular and mechanical effects resulting in increased epithelial permeability,
Giardia lamblia also causes intestinal abnormalities in the host, such as the loss of intestinal brush border surface area and villus flattening, similar to that observed in celiac disease [
47]. Consequently, infection with
Giardia lamblia can lead to malabsorption which in rare cases may result in vitamin K deficiency and impaired coagulation [
48] as observed in the discussed patient. However, since eosinophilia is often present in infections with
Giardia lamblia but was not present in this case, giardiasis can probably be ruled out as a diagnosis.
Due to evidence of malabsorption in this patient, the differential diagnosis should also include Crohn’s disease, which can involve all parts of the gastrointestinal tract and present with increased CRP levels (as found in the discussed patient), nausea, vomiting and epigastric pain [
49‐
51]. Although Crohn’s disease usually afflicts patients in their 20s and 30s, exacerbation during pregnancy is typically seen in the 2nd or 3rd trimester, but not in the 1st trimester as in the discussed patient. Other forms of inflammatory bowel disease such as ulcerative colitis and indeterminate colitis, predominantly involving the rectum and variable parts of the colon, are usually not associated with malabsorption and are thus unlikely diagnoses in this case.
All these considerations finally lead to the suggested diagnostic approach of (1) endoscopy with duodenal biopsies, (2) serological testing for tTG-IgA antibodies, (3) quantitative analysis of immunoglobulins and Ig subtypes to rule out IgA deficiency, and (4) testing for parasites and ova in stool, or duodenal aspirate analysis for exclusion of giardiasis.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.