HEG has a pathophysiological mechanism that depends on many causes. Inflammation has a critical role in HEG . HEG may be severe enough to require hospitalization. It may even progress to central pontine myelinolysis and Wernicke's encephalopathy. Therefore, early diagnosis and treatment of HEG are very important for maternal and child health .
Although the link between HEG and inflammation is not fully understood, studies on inflammation markers in HEG patients suggest that there is a strong relationship between them [6,18]. The role of inflammatory processes in the development of HEG has been studied from various aspects. WBC, neutrophil, monocytes, lymphocyte, basophil, and eosinophil counts, which are among the hematological parameters, are important determinants of the inflammatory process. While neutrophils are common in active inflammation, lymphocyte counts reflect the regulatory pathway of the same process .
Caglayan et al.'s studies, no significant difference was found between the HEG and control groups in terms of lymphocyte and neutrophil counts . Differently, in another study, neutrophil and monocyte counts were higher in the HEG group, while lymphocyte counts were higher in the control group . In another clinical study, neutrophil levels were found to be higher in the HEG group, while the lymphocyte count was found to be lower . In our study, monocyte and neutrophil counts were found to be significantly higher in the HEG group compared to the control group. Eosinophil and lymphocyte levels were found to be lower. In addition, when the HEG subgroups are compared, monocyte and neutrophil counts increase, and eosinophils and lymphocyte counts decrease from mild to severe groups.
Mean platelet volume (MPV) is a machine calculated measurement of the average size of platelets present in the blood and is typically included in blood tests as part of the CBC. MPV is an indicator of inflammation due to increased destruction of platelets . There are studies showing that there is no difference between the HEG group and control groups in terms of MPV values [23-24]. Differently, MPV values were found to be higher in the HEG group in our study. In addition, a significant difference was found between the mild to the moderate group and the moderate to severe group according to MPV value (p<0.05).
Recently, it has been stated that inflammatory markers such as PCT, RDW, and MPV obtained from complete blood count have prognostic and predictive properties in various diseases such as gynecological and gastrointestinal malignancies, autoimmune diseases, and coronary artery diseases [25-26]. There are not many studies on the relationship between PCT and HEG. Tayfur et al.'s PCT values were found to be higher in women with HEG in their study. In the same study, mild, moderate, and severe HEG cases were compared and it was stated that PCT values were higher in severe HEG cases . In our study, PCT values were found to be significantly higher in the HEG group than in the control group. In addition, mild, moderate, and severe HEG cases were compared, and PCT values increase as one goes from the mild group to the severe group. A positive and significant relationship was found between PCT values and HEG..
RDW, another parameter in the complete blood count, shows the distribution of red blood cell sizes. RDW tends to increase hemolysis and red blood cell production disorders. RDW is mainly used for diagnosing anemia. It has been shown that RDW is increased in acute and chronic conditions such as pulmonary embolism, acute renal failure, and skin disease .
It is reported that HRR alone is a stronger prognostic indicator than Hb or RDW. As the reason for this, it is thought that combining the prognostic information from Hemoglobin and RDW by HRR will provide more information than a single variable . HRR is a recently used inflammatory marker derived from Hb and RDW, which are complete blood count parameters used in routine practice. In addition, it has been shown to be a bad prognostic factor alone in many cancers such as stomach cancer and lung cancer [28-29]. Cintesun et al.'s found no significant difference in RDW between the HEG and control groups in their study. In the same study, only a relationship was found between RDW and ketonuria among the available parameters. Contrary to this study, RDW was found to be higher in the control group compared to the HEG group in our study. However, no significant difference was observed between mild, moderate, and severe groups .
HEG patients are expected to develop hemoconcentration due to vomiting and dehydration. Bulanik et al.'s Hemoglobin and white blood count (WBC) values were not different from the control group in their study . Unlike this study, in our study, WBC values were found to be higher in the HEG group than in the control group.
PLR and NLR are used as important markers in many diseases such as Diabetes Mellitus, kidney failure, heart diseases, inflammatory diseases, autoimmune diseases, and hypertensive disorders . It is stated that these two special indicators increase gastrointestinal diseases, gynecological diseases, malignancies, cardiac diseases, and inflammation [33-34]. Looking at the literature, there are a few studies on the severity of MLR, PLR, NLR, and HEG. Soysal et al.'s In the study conducted by MLR, PLR, and NLR levels were reported to be higher in the patient group. In the same study, a significant correlation was found between increasing ketonuria levels and MLR, PLR, and NLR . In another study, PLR and NLR levels were found to be high in HEG patients. However, no correlation was found between PLR and NLR values and the degree of ketonuria . Kan et al.'s In their study, PLR, and NLR levels were found to be higher in the HEG group. However, no correlation was found between the severity of the disease and PLR and NLR values . In another similar study, a significant relationship was found between NLR levels and HEG groups . In our study, PLR, NLR, and MLR values were found to be higher in the HEG group. PLR, NLR, MLR values increase as one goes from the mild group to the severe group. A significant positive correlation was found between HEG group and PLR, NLR, and MLR values (p<0.05). NLR> 3.06, PLR> 155.4, and MLR> 0.22 rates were determined statistically and these parameters were significantly associated with increased risk of HEG disease.
There is no study in the literature regarding HRR in patients with hyperemesis gravidarum. We believe that the data we obtained in this study will lay the groundwork for future studies. In our study, HRR levels were found to be significantly higher in the HEG group than in the control group. When the HEG subgroups were examined, no significant difference was observed between mild, moderate and severe groups. There was no significant correlation between HRR and HEG (p>0.05). However, in our ROC analysis, the rate of HRR>0.97 was detected and it was found to be significantly associated with increased risk of HEG.
Eosinophil lymphocyte ratio (ELR) is a new marker evaluated in inflammation and malignancies. In one study, high ELR levels were associated with smoking. It has been said that it may be a useful indicator of systemic disease . It has been reported that ELR helps in distinguishing those with and without hypersensitivity to non steroidal anti inflammatory drugs in patients with bronchial asthma . In addition, it has been reported that increased ELR level worsens the survival of endometrial cancer and is associated with the high risk group . There are not many studies on ELR in the obstetric field in the literature. It is seen that some studies have been done in other medical fields. Our study is the first in the literature investigating the relationship between ELR and HEG patients. In our study, ELR levels were found to be significantly higher in the healthy control group. However, in HEG subgroups, the level of ELR decreases from mild to severe. In addition, a negative correlation was found between ELR value and HEG in the correlation study. However, according to the data we obtained, ELR levels were not associated with an increased risk of HEG disease.
Limitations of this study: First, the patient data was single center, the number of patients was not very large, and it was a retrospective study. Second, only HRR, PLR, NLR, ELR, MLR, and other hematological parameters are used as inflammatory markers. The strength of our study is that it is the first study that will lead to the demonstration of the relationship of MLR, PLR, and NLR as well as the new parameters ELR and HRR with HEG.