Antenatal management of severe feto-maternal alloimmune thrombocytopenia: HLA incompatibility may affect responses to fetal platelet transfusions

In feto-maternal alloimmune thrombocytopenia (FMAIT), severe hemorrhage, particularly intracranial haemorrhage (ICH), may occur before delivery. Management strategies to prevent ICH in high-risk pregnancies include maternal administration of intravenous Ig with or without steroids and fetal platelet transfusions. This report describes a patient who lost three fetuses with ICH because of FMAIT due to anti- HPA-1a. ICH occurred earlier in successive pregnancies (at 28, 19, and 16 weeks of gestation) despite maternal treatment with intravenous Ig and steroids from 14 weeks of gestation in the third pregnancy. The fourth pregnancy was managed by administering weekly intraperitoneal injections of Ig to the fetus from 12 to 18 weeks of gestation. At 18 weeks, there was no evidence of ICH, but the fetal platelet count was only 12 x 10(9)/L. Serial fetal platelet transfusions were started, but there were poor responses because of immune destruction of the transfused platelets by maternal HLA antibodies. There were improved responses to transfusions prepared from the mother and from HLA- compatible HPA-1a-negative donors. At 35 weeks of gestation, a normal infant was delivered by Caesarean section after 20 platelet transfusions. There was prolonged thrombocytopenia in the baby for 15 weeks after birth, probably due to transfer of HPA-1a antibodies in the transfusions of unwashed maternal platelets. The optimal management of pregnancies likely to be severely affected by FMAIT is still evolving. Intensive management was successful in this case, but a successful outcome cannot be guaranteed in severely affected cases. This is the first time that HLA incompatibility has been found to complicate fetal transfusion therapy.     

Spontaneous Rise of Fetal Platelet Counts Despite Increasing anti-HPA-5b Antibodies

Background and objectives: Maternal anti-HPA alloantibodies are a rare cause of severe fetal thrombocytopenia. So far there have been no reports on the dynamics of maternal anti-HPA-5 during gestation and its effect on the fetus. Materials and methods: We monitored maternal anti-HPA-5b antibody titers and fetal platelet counts during gestation in a woman with known anti-HPA-5b alloimmunization. The patient was a 32-year-old woman in her third pregnancy. The 1st pregnancy and delivery of a healthy child had been uneventful. At delivery, anti-HPA-5b was detectable in the maternal serum. A 2nd pregnancy ended in early miscarriage. Results: A steady rise in the alloantibody titer was recorded throughout the 3rd pregnancy. Therefore, cordocentesis was performed at 28 weeks of gestation (platelet count 76×10⁹/l). Serial platelet transfusions were administered to the fetus at 28, 32, and 37 weeks of gestation. The platelet counts rose spontaneously thereafter and were 220×10⁹/l at delivery, despite an increase in the anti-HPA-5b antibody titer. The child developed normally during the first year of life. Conclusions: This case illustrates the spontaneous recovery of fetal platelet counts in late pregnancy despite a rise in maternal alloantibody titer.     

Neonatal alloimmune thrombocytopenia

Neonatal alloimmune thrombocytopenia (NAIT) occurs when maternal alloantibodies to antigens present on fetal platelets cause their immune destruction resulting in thrombocytopenia in the newborn infant or fetus. Bleeding may be severe; intracranial haemorrhage and permanent neurological damage are the most serious complications. Despite the severity of the disease, there is often a delay in making the correct diagnosis and instigating appropriate treatment. Recent evidence that NAIT is more common than has previously been recognised, a better understanding of the molecular basis of platelet serology and advances in technology, which have made it possible to take blood samples from fetuses and transfuse them in utero, have all contributed to a growing interest in this condition. In addition, it is exciting to realise that an aggressive approach to the management of established cases and 'at risk' pregnancies can prevent serious neurological sequelae and dramatically improve the outcome for affected infants.     

Fetal and neonatal alloimmune thrombocytopenia: recommendations for evidence-based practice,an international approach

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) may result in severe bleeding, particularly fetal and neonatal intracranial haemorrhage (ICH). As a result, FNAIT requires prompt identification and treatment; subsequent pregnancies need close surveillance and management. An international panel convened to develop evidence-based recommendations for diagnosis and management of FNAIT. A rigorous approach was used to search, review and develop recommendations from published data for: antenatal management, postnatal management, diagnostic testing and universal screening. To confirm FNAIT, fetal human platelet antigen (HPA) typing, using non-invasive methods if quality-assured, should be performed during pregnancy when the father is unknown, unavailable for testing or heterozygous for the implicated antigen. Women with a previous child with an ICH related to FNAIT should be offered intravenous immunoglobulin (IVIG) infusions during subsequent affected pregnancies as early as 12 weeks gestation. Ideally, HPA-selected platelets should be available at delivery for potentially affected infants and used to increase the neonatal platelet count as needed. If HPA-selected platelets are not immediately available, unselected platelets should be transfused. FNAIT studies that optimize antenatal and postnatal management, develop risk stratification algorithms to guide management and standardize laboratory testing to identify high risk pregnancies are needed.     

Immune thrombocytopenic purpura in pregnancy

Of all pregnant women 1.2% have platelet counts below 100 x 10(9)/l. Only a small proportion of these have immune thrombocytopenic purpura (ITP). ITP is caused by antibodies directed against one's own platelets and may affect the mother as well as the fetus. No cases with documented intrauterine fetal bleeding have been reported. The most critical time for the fetus is usually a few days after birth. Hitherto the patient's history has been the best predictor of maternal and neonatal complications. Diagnostic cordocentesis entails a considerable risk and is to be discouraged in most situations. Intrauterine transfusions are effective only for a very limited period. There is no evidence that caesarean section protects the thrombocytopenic infant from intracranial haemorrhage. We therefore recommend restricting caesarean section to obstetric indications and to situations with proven fetal thrombocytopenia and enhanced obstetric risk. The safe cut-off level has yet to be ascertained. It is mandatory to control the newborn's platelet count during the first three days of life.     

Management of alloimmune thrombocytopenia: antenatal diagnosis and in utero transfusion of maternal platelets

Neonatal alloimmune thrombocytopenia (NAIT) can cause severe bleeding in the central nervous system (CNS) and death or severe neurologic sequelae. The expression of the PLA1 antigen is detectable as early as 19 weeks of gestation. Alloimmunization can therefore lead to fetal thrombocytopenia very early in pregnancy. Until recently, we have had no means of detecting and assessing the severity of fetal thrombocytopenia during pregnancy. The level of the maternal antibody is not of a predictable value since 20% of the mothers had no circulating antibodies in our series. An alternative approach is to carry out investigations on fetal blood samplings. This management leads to an exact knowledge of the fetal status and antenatal diagnosis is feasible as early as the 21st week of gestation. Early diagnosis facilitates appropriate management and makes possible such therapeutic options as in utero maternal platelet transfusions. We report our experience in the antenatal diagnosis and management of nine cases with in utero transfusion in the six cases with severe thrombocytopenia. All neonates did well, with no signs of bleeding at birth. No side effects of therapy were noted after a period ranging from 6 months to 3 years.     

Two successful pregnancies in a woman with chronic thrombotic thrombocytopenic purpura treated by plasma infusion

A 21-year-old primigravida in her 20th week of pregnancy developed TTP. She was managed with weekly or semiweekly plasma infusions and delivered a healthy 1.6 kg baby 2 weeks prior to the expected date of delivery. After delivery she continued to have active TTP with thrombocytopenia which responded repeatedly to plasma infusion though their frequency gradually decreased to about one unit every 3-4 weeks. Three years after the birth of the first child she conceived again and was easily managed with repeated plasma infusions although the frequency and amount of plasma required to prevent thrombocytopenia were increased. She delivered a normal 3.4 kg term baby after which she again had a decreased plasma requirement. This is the first report of a woman with 5 years of active TTP managed with plasma alone. She experienced two pregnancies in which both mother and infant survived. We believe that the use of plasma in the management of TTP during pregnancy will improve the survival rate of both mother and infant. At the time of second birth, the platelet count was low in the mother but normal in the baby. This suggests that the platelet depressing factor of this patient does not cross the placental barrier.     

Alloimmune thrombocytopenia of the fetus and the newborn

Fetal/neonatal alloimmune thrombocytopenia results from a maternal alloimmunization against fetal platelet antigens. Care must be taken in making a correct diagnosis that eliminates other causes of thrombocytopenia that may occur during pregnancy. Biological diagnosis is normally made by platelet genotyping and search for the maternal alloantibody using monoclonal antibodies in an antigen capture assay. Fetal alloimmune thrombocytopenia, when severe, may result in intracerebral hemorrhage leading to hydrocephalus and death of the fetus. Neonatal alloimmune thrombocytopenia may be present in an otherwise healthy infant. While screening procedures are not in place to detect fetal/neonatal alloimmune thrombocytopenia, it is true that fetal hydrocephalus, unexplained fetal thrombocytopenia with or without anemia, or recurrent miscarriages should be adequate indicators for suspecting fetomaternal alloimmune thrombocytopenia. Multiparous women with a history of giving birth to at least one alloimmune thrombocytopenic infant should be carefully monitored in subsequent pregnancies. Postnatal management of neonatal alloimmune thrombocytopenia involves compatible platelet transfusion in the neonate. Antenatal management of fetal alloimmune thrombocytopenia is controversial and includes a combination of maternal intravenous gamma globulin (i.v.IgG) administration, intrauterine platelet transfusions, and corticosteroid therapy, while monitoring fetal platelet counts closely throughout the course of pregnancy. Screening of pregnant women may become a public health issue only after antenatal therapy is more standardized.     

Efficacy of HPA-1a (PlA1)-negative platelets in a patient with post-transfusion purpura

Post-transfusion purpura (PTP) is a rare form of alloimmune thrombocytopenia that is self-limited but which carries a 10-15% mortality related to fatal hemorrhage. Immunomodulatory therapies such as plasmapheresis and intravenous immunoglobulin G (IVIg) can shorten the duration of thrombocytopenia. However, in a bleeding patient with PTP, more urgent therapy may be required. Textbooks of hematology [1-3] as well as reports in the literature [4,5] suggest that patients do not respond to platelet transfusions. We report a case of PTP in a patient homozygous for HPA-1b who suffered an intracranial hemorrhage. The patient was treated with IVIg and plasmapheresis. Because of her life-threatening bleeding, we also transfused the patient with HPA-1a-negative platelets. These transfusions consistently resulted in transient improvements in her platelet counts and may have limited the degree of intracranial bleeding. Our experience suggests that transfusion of platelets that lack the offending epitope in patients with PTP may be efficacious.     

European collaborative study of the antenatal management of feto-maternal alloimmune thrombocytopenia

The aims of this study were to determine whether the severity of fetomaternal alloimmune thrombocytopenia (FMAIT) in the current pregnancy could be predicted from the history of FMAIT in previous pregnancies, and to assess the effects of different types of antenatal intervention. Fifty-six fetuses were studied that all had a sibling affected by FMAIT due to human platelet antigen 1a (HPA-1a) alloimmunization. Cases with a sibling history of antenatal intracranial haemorrhage (ICH) or severe thrombocytopenia (platelet counts of < 20 x 109/l) had significantly lower pretreatment platelet counts than cases whose siblings had less severe thrombocytopenia or postnatal ICH. Maternal therapy resulted in a platelet count exceeding 50 x 109/l in 67% of cases. None of the fetuses managed by serial platelet intrauterine transfusions (IUT) suffered ICH following treatment. However, several serious complications arose with fetal blood sampling (FBS). Overall, intervention improved outcome, as three study cases suffered from antenatal ICH and three others died whereas 15 study cases had a sibling with an ICH, eight of whom died. The results of this study suggest that the start of therapy can be stratified on the basis of the sibling history of FMAIT, and support the use of maternal therapy as first-line treatment.     

Relationships between severe neonatal thrombocytopenia and maternal characteristics in pregnancies associated with autoimmune thrombocytopenia

In pregnant women with antecedents of autoimmune thrombocytopenia (AITP), no predictive factor for severe fetal thrombocytopenia has been identified. We evaluated the relationships between the course of the maternal disease before and during pregnancy and the risk of severe fetal thrombocytopenia, in 64 pregnant women with known chronic AITP antecedents, over a 12-year period. 28 pregnant women had undergone splenectomy before pregnancy and 17 experienced severe thrombocytopenia (< 50 × 10⁹/l) during pregnancy (monthly determination). Eight infants presented with severe thrombocytopenia at birth (12.5%), and four in the following days (6.25%). No severe haemorrhage was observed. Severe thrombocytopenia at birth was present in 57% (CI 95% 18–90%) of the infants born to mothers with severe pregnancy-associated thrombocytopenia and splenectomy antecedents, and in 0% (CI 95% 0–15%) of the infants born to mothers who presented none of these antecedents ( P  = 0.001). In thrombocytopenic mothers the infant platelet counts at birth were positively correlated to the nadir maternal platelet count during the index pregnancy ( r  = 0.42, P  = 0.0075).
These results suggest that severe autoimmune disease is a risk factor for severe fetal thrombocytopenia, and that pregnant women with no antecedent of splenectomy nor severe thrombocytopenia during pregnancy have a very low risk of severe fetal thrombocytopenia.     

Treatment of idiopathic thrombocytic purpura in pregnancy by high-dose intravenous immunoglobulin

Summary ITP in pregnancy may lead to fetal thrombocytopenia caused by the transplacental passage of maternal antiplatelet antibody. The most hazardous complication in the infant is intracranial hemorrhage. In addition ITP in pregnancy is reported to be associated with an increased abortion rate and an elevated fetal morbidity and mortality. Therefore obstetric management must aim at increasing maternal and fetal platelets. Severel therapeutic approaches to the treatment of ITP in pregnancy are evaluated. Two cases of ITP in pregnancy are reported. Administration of high-dose intravenous immunoglobulin is introduced as a new therapy for ITP in pregnancy. The rapid reversal of thrombocytopenia following immunoglobulin G administration suggests that it is useful especially as emergency treatment for ITP in pregnancy.     

The management of alloimmune neonatal thrombocytopenia.

Neonatal alloimmune thrombocytopenia (NAITP), defined as thrombocytopenia (platelet count < 150 x 10(9)/l) due to transplacentally acquired maternal platelet alloantibodies, occurs in approximately 1 per 1200 live births in a Caucasian population. In such a population, the majority (> 75 percent) of cases are due to fetomaternal incompatibility for the platelet specific alloantigen, HPA-1a (P1A1, Zwa). Incompatibility for the HPA-5b (Bra) alloantigen is the next most frequent cause of NAITP in Caucasians; much less common is NAITP due to incompatibility for HLA, blood group ABO or other platelet-specific antigens. In non-Caucasian populations (e.g. Orientals) HPA-1a incompatibility is a rare cause of NAITP and other alloantigens e.g. HPA-4b (Penb, Yuka) are implicated. The greatest clinical challenge relates to the antenatal management of pregnant women alloimmunized to the HPA-1a (P1A1, Zwa) antigen, and particularly the subset of such women who have a history of a previously affected infant with severe thrombocytopenia and/or intracranial hemorrhage (ICH). The risk of antenatal ICH in the fetus of such women is high enough to merit intervention, either weekly infusion of high-dose intravenous immunoglobulin G (IVIG) with or without corticosteroids given to the mother (the preferred approach in North American centres), or repeated in-utero fetal platelet transfusions (the preferred treatment approach in some European centres). Post-natal management of severely affected infants centres on the rapid provision of compatible antigen-negative platelets harvested from the mother or a phenotyped donor. The value of antenatal screening programs to detect 'at risk' alloimmunized women during pregnancy continues to be debated.     

Acute myelogenous leukemia developing in pregnancy with complete remission--a case report

A 27-year-old woman was admitted to our hospital complaining of purpuras and legs' edema in the 38th week of pregnancy. On admission, the hemoglobin was 7.8 g/dl, platelets 20,000/microliter and WBC 6,600/microliters with 52% blast cells. Bone marrow aspirate demonstrated 77.2% myeloblasts with prominent Auer rods, consistent with acute myelogenous leukemia. Receiving packed-red-cell and platelet transfusions, she delivered a normal male infant in the 39th week of pregnancy by normal labor. After delivery, she was placed on a combination chemotherapy of BHAC-MMP, subsequently DNR added. Four weeks later, a complete remission was obtained, lasting for almost one year, and her child has grown well without hematological disorder. Microscopic findings of the placenta obtained at delivery revealed no invasion of leukemic cells, but 9% blast cells were present in the placental cord blood. We reviewed 18 cases reported in Japan of acute leukemia in gestational period, that could obtain complete remission and keep the children growing well. Placental transmission of leukemic cells from mother to infant was discussed.     

Antibody Removal Therapy Used Successfully at Delivery of a Pregnant Patient with Glanzmann''s Thrombasthenia and Multiple Anti-Platelet Antibodies

A 31-year-old Japanese woman with Glanzmann's thrombasthenia became pregnant voluntarily. She had had transfusions with more than 60 units for severe bleeding. She had multiple antibodies against HLA antigens and platelet glycoprotein IIb/IIIa. No compatible platelets were available. To prevent serious hemorrhage during her delivery, antibody removal therapy was carried out three times. Large molecules including immunoglobulins were removed from more than 3 liters of plasma each time. After the titer of antiplatelet antibodies had decreased in the patient's blood, antihuman globulin-lymphocyte cytotoxicity test compatible platelets were transfused. Her bleeding time improved and delivery was induced successfully despite atonic hemorrhage of about 2,000 g of blood. Her infant had no bleeding problems. This patient is the first with Glanzmann's thrombasthenia to receive antibody removal therapy at delivery.     

Immune thrombocytopenia: effects of maternal gamma globulin infusion on maternal and fetal serum, platelet, and monocyte IgG

A 24-year-old woman with lupus-like serologic abnormalities had immune thrombocytopenia that resolved after splenectomy, but increased quantities of platelet surface IgG persisted. Three years later, during the 36th week of her first pregnancy, gamma globulin (400 mg/kg daily for 5 days) was administered intravenously to decrease the risk and/or severity of immune thrombocytopenia in her infant. The infusion produced marked but transient elevations of maternal concentrations of serum IgG and quantities of monocyte surface IgG, but no significant changes in Fc receptor-mediated rosetting of peripheral blood monocytes with antibody-sensitized platelets occurred. Modest increases in quantities of platelets and plasma platelet-specific IgG were demonstrated. The infant, delivered by cesarean section 2 days after the end of the infusion, had a normal platelet count; cord blood had a normal concentration of serum IgG, but an elevated quantity of platelet surface IgG (by comparison with values for normal adults). Infant values of plasma platelet-specific IgG, monocyte surface IgG, and monocyte/platelet rosettes also were within the range of normal for adults. Anticytomegalovirus antibody was present in large amounts in the gamma globulin infused, first appeared in maternal serum after therapy, and was detected in cord serum. The significance of these observations to the management of immune neonatal thrombocytopenia is discussed.     

Neonatal outcome in alloimmune thrombocytopenia after maternal treatment with intravenous immunoglobulin

Background

Weekly maternal intravenous immunoglobulin (IVIG) is the cornerstone of antenatal treatment of foetal and neonatal alloimmune thrombocytopenia (FNAIT). The aim of this study was to describe the neonatal outcome and management in neonates with FNAIT treated antenatally with IVIG.

Materials and methods

All neonates treated antenatally and delivered at our centre between 2006 and 2012 were included in the study. We assessed the neonatal outcome and management, including the occurrence of intracranial haemorrhage, platelet count at birth and need for postnatal platelet transfusions or postnatal IVIG treatment.

Results

A total of 22 neonates were included of whom 12 (55%) had severe thrombocytopenia at birth (platelet count ≤50×10⁹/L). Most neonates (67%, 8/12) with severe thrombocytopenia received a platelet transfusion after birth. None of the neonates required postnatal treatment with IVIG. Three neonates had petechiae and haematomas, without clinical consequences. One foetus suffered from intracranial haemorrhage, which was detected just before the planned start of antenatal IVIG at 28 weeks’ gestation.

Discussion

Our results suggest that antenatal maternal IVIG and, if necessary, postnatal matched platelet transfusions, are effective and safe for the treatment of FNAIT.     

Chronic intravascular coagulation associated with chronic myelocytic leukemia. Use of heparin in connection with a surgical procedure.

A women with Philadelphia chromosome-positive chronic myelocytic leukemia lived nearly 12 years from the time of diagnosis. During most of this period she received no therapy, and marked cyclic oscillations in the white blood cell count were documented. The last two years of her illness were marked by a hemorrhagic disorder associated with hypofibrinogenemia, thrombocytopenia, increased plasma fibrinopeptide A concentration and markedly elevated serum levels of fibrin degradation products. The coagulation disorder was rapidly reversible on several occasions with heparin therapy. After treatment with heparin and platelet transfusions, the patient underwent successful resection of a large ovarian cyst with excellent hemostasis during the procedure. Postoperatively, the administration of heparin and platelets was discontinued and a large wound hematoma developed. After resumption of therapy with heparin and platelets, the remainder of her postoperative course was uneventful. The literature on the subject is reviewed and tentative guidelines are offered concerning the management of patients with intravascular coagulation who require diagnostic or therapeutic surgical procedures.     

Pregnancy in patients with beta-thalassemia intermedia: outcome of mothers and newborns

Little is known about the outcome of pregnancy in women with beta-thalassemia intermedia (TI). Over 10 years, maternal and neonatal outcomes of women with TI followed at a single thalassemia center were reviewed. Nine spontaneous pregnancies in five women with TI were studied. Six pregnancies resulted in live newborns; two were complicated by first-trimester abortions and one by an unexplained intrauterine fetal death at 36 weeks' gestation. Two patients had splenectomy before pregnancy: one required cesarean delivery and splenectomy at 31(2/7) weeks' gestation for worsening hemolytic anemia and thrombocytopenia and another had splenectomy 8 weeks postpartum for symptomatic hypersplenism. Two patients had received transfusions before pregnancy, and two required them for the first time during pregnancy and developed antibodies, which contributed to worsening of their anemia and repeated transfusions. The mean number of transfusions received during pregnancy was 8.0 +/- 5.2 units. The mean lowest hemoglobin level in pregnancy was 5.2 +/- 2.0 g/dl. Cesarean delivery was performed in 42.9% of cases. Mean gestational age at delivery was 36.7+/- 3.1 weeks with intrauterine growth restriction (IUGR) complicating 57.1% of cases. In conclusion, IUGR complicates more than half of pregnancies with TI. Transfusions are needed in most cases, even in non-transfusion-dependent patients. Postpartum splenectomy might be necessary in some patients.     

ITP in pregnancy and the newborn: Introduction

Summary Idiopathic thrombocytopenic purpura (ITP) occurs more commonly in young women and is one of the commonest immune mediated disorders in pregnancy. It may exist as an incidental finding in an otherwise healthy pregnant woman or may be associated with symptomatic reduction in the platelet count and varying degrees of clinical hemorrhage. The condition termed incidential thrombocytopenia of pregnancy is invariably associated with a platelet count of greater than 100×10⁹/L and a very low incidence of fetal thrombocytopenia. Symptomatic thrombocytopenia is more commonly associated with low platelet counts in the fetus (estimated between 20%–40%). It has recently been suggested that the incidence of fetal thrombocytopenia is substantially lower than this figure. The management of ITP in pregnancy is complicated by the fact that fetal thrombocytopenia is difficult to diagnose and carries substantial risks during the delivery process with rare cases of fetal hemorrhage occurring spontaneously in utero. Unfortunately there are no laboratory studies that can be performed precisely in the mother that may predict the occurrence of fetal thrombocytopenia. Maternal management is usually directed towards treatment of maternal symptoms. Maternal treatment or response to treatment is inconsistently associated with predictible changes in the fetal platelet count. Obstetric management is aimed at reducing the risks of life threatening fetal hemorrhage occurring at the time of delivery, and fetal management is directed towards the obtaining of fetal platelet samples in order to plan an appropriate strategy for obstetrical delivery. Fetal blood samples are obtained either by a scalp vein puncture at the time of delivey or earlier in gestation by the use of the newer technique termed percutaneous umbilical blood sampling. Fetuses with platelet counts of less then 50×10⁹/L are generally delivered by cesarean section whereas those with counts greater than 50×10⁹/L are allowed to proceed with vaginal delivery assuming no obstetrical contraindications exist. The use of IVIgG therapy during pregnancy has theoretical implications on improving platelet counts in the mother in situations of severe hemorrhage, however cannot be considered to be appropriate treatment for the prevention of fetal thrombocytopenia, since the exogenous transport of IVIgG across the placenta appears to be inconsistent and unpredictible. The mainstay of maternal management continues to be corticosteroids and women who have failed this therapy, who continue to have bleeding or those in whom iatrogenic complications of steroids exist are candidates for IVIgG.Presented at the International Workshop on ITP, August 26 and 27, 1988, Lucerne, Switzerland